diff --git a/contrib/dblink/dblink.cpp b/contrib/dblink/dblink.cpp
index 01586432b..822c39c0a 100755
--- a/contrib/dblink/dblink.cpp
+++ b/contrib/dblink/dblink.cpp
@@ -1781,7 +1781,7 @@ static char** get_pkey_attnames(Relation rel, int16* indnkeyatts)
     indexRelation = heap_open(IndexRelationId, AccessShareLock);
     ScanKeyInit(&skey, Anum_pg_index_indrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
 
-    scan = systable_beginscan(indexRelation, IndexIndrelidIndexId, true, SnapshotNow, 1, &skey);
+    scan = systable_beginscan(indexRelation, IndexIndrelidIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid(indexTuple = systable_getnext(scan))) {
         Form_pg_index index = (Form_pg_index)GETSTRUCT(indexTuple);
diff --git a/contrib/sepgsql/label.cpp b/contrib/sepgsql/label.cpp
index c9ad1ece1..34ef4f4a0 100644
--- a/contrib/sepgsql/label.cpp
+++ b/contrib/sepgsql/label.cpp
@@ -634,7 +634,7 @@ static void exec_object_restorecon(struct selabel_handle* sehnd, Oid catalogId)
      */
     rel = heap_open(catalogId, AccessShareLock);
 
-    sscan = systable_beginscan(rel, InvalidOid, false, SnapshotNow, 0, NULL);
+    sscan = systable_beginscan(rel, InvalidOid, false, NULL, 0, NULL);
     while (HeapTupleIsValid(tuple = systable_getnext(sscan))) {
         Form_pg_database datForm;
         Form_pg_namespace nspForm;
diff --git a/src/common/backend/catalog/aclchk.cpp b/src/common/backend/catalog/aclchk.cpp
index 1fa648a01..05088d951 100644
--- a/src/common/backend/catalog/aclchk.cpp
+++ b/src/common/backend/catalog/aclchk.cpp
@@ -1526,7 +1526,7 @@ void RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
 
         ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objid));
 
-        scan = systable_beginscan(rel, DefaultAclOidIndexId, true, SnapshotNow, 1, skey);
+        scan = systable_beginscan(rel, DefaultAclOidIndexId, true, NULL, 1, skey);
 
         tuple = systable_getnext(scan);
 
@@ -1623,7 +1623,7 @@ void RemoveDefaultACLById(Oid defaclOid)
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(defaclOid));
 
-    scan = systable_beginscan(rel, DefaultAclOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(rel, DefaultAclOidIndexId, true, NULL, 1, skey);
 
     tuple = systable_getnext(scan);
 
@@ -2987,7 +2987,7 @@ static void ExecGrant_Largeobject(InternalGrant* istmt)
         /* There's no syscache for pg_largeobject_metadata */
         ScanKeyInit(&entry[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(loid));
 
-        scan = systable_beginscan(relation, LargeObjectMetadataOidIndexId, true, SnapshotNow, 1, entry);
+        scan = systable_beginscan(relation, LargeObjectMetadataOidIndexId, true, NULL, 1, entry);
 
         tuple = systable_getnext(scan);
         if (!HeapTupleIsValid(tuple))
@@ -6153,7 +6153,7 @@ bool pg_largeobject_ownercheck(Oid lobj_oid, Oid roleid)
 
     ScanKeyInit(&entry[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(lobj_oid));
 
-    scan = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, SnapshotNow, 1, entry);
+    scan = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, NULL, 1, entry);
 
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
@@ -6483,7 +6483,7 @@ bool pg_extension_ownercheck(Oid ext_oid, Oid roleid)
 
     ScanKeyInit(&entry[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ext_oid));
 
-    scan = systable_beginscan(pg_extension, ExtensionOidIndexId, true, SnapshotNow, 1, entry);
+    scan = systable_beginscan(pg_extension, ExtensionOidIndexId, true, NULL, 1, entry);
 
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
diff --git a/src/common/backend/catalog/cstore_ctlg.cpp b/src/common/backend/catalog/cstore_ctlg.cpp
index c32c25b06..5b1f7038a 100644
--- a/src/common/backend/catalog/cstore_ctlg.cpp
+++ b/src/common/backend/catalog/cstore_ctlg.cpp
@@ -909,7 +909,7 @@ static void drop_delta_rel(Oid deltataRelId)
     Relation depRel = relation_open(DependRelationId, RowExclusiveLock);
     ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId));
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(deltataRelId));
-    scan = systable_beginscan(depRel, DependDependerIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 2, key);
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         simple_heap_delete(depRel, &tup->t_self);
     }
diff --git a/src/common/backend/catalog/dependency.cpp b/src/common/backend/catalog/dependency.cpp
index bc40d9610..dd46eeda9 100644
--- a/src/common/backend/catalog/dependency.cpp
+++ b/src/common/backend/catalog/dependency.cpp
@@ -569,7 +569,7 @@ static void findDependentObjects(const ObjectAddress* object, int flags, ObjectA
     } else
         nkeys = 2;
 
-    scan = systable_beginscan(*depRel, DependDependerIndexId, true, SnapshotNow, nkeys, key);
+    scan = systable_beginscan(*depRel, DependDependerIndexId, true, NULL, nkeys, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend foundDep = (Form_pg_depend)GETSTRUCT(tup);
@@ -718,7 +718,7 @@ static void findDependentObjects(const ObjectAddress* object, int flags, ObjectA
     } else
         nkeys = 2;
 
-    scan = systable_beginscan(*depRel, DependReferenceIndexId, true, SnapshotNow, nkeys, key);
+    scan = systable_beginscan(*depRel, DependReferenceIndexId, true, NULL, nkeys, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend foundDep = (Form_pg_depend)GETSTRUCT(tup);
@@ -1076,7 +1076,7 @@ static void deleteOneObject(const ObjectAddress* object, Relation* depRel, int f
     } else
         nkeys = 2;
 
-    scan = systable_beginscan(*depRel, DependDependerIndexId, true, SnapshotNow, nkeys, key);
+    scan = systable_beginscan(*depRel, DependDependerIndexId, true, NULL, nkeys, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         simple_heap_delete(*depRel, &tup->t_self);
@@ -1100,7 +1100,7 @@ static void deleteOneObject(const ObjectAddress* object, Relation* depRel, int f
         } else
             nkeys = 2;
 
-        scan = systable_beginscan(*depRel, DependReferenceIndexId, true, SnapshotNow, nkeys, key);
+        scan = systable_beginscan(*depRel, DependReferenceIndexId, true, NULL, nkeys, key);
 
         while (HeapTupleIsValid(tup = systable_getnext(scan))) {
             Form_pg_depend Pinnedobj = (Form_pg_depend)GETSTRUCT(tup);
@@ -2419,7 +2419,7 @@ char* getObjectDescription(const ObjectAddress* object)
             ScanKeyInit(
                 &skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-            rcscan = systable_beginscan(castDesc, CastOidIndexId, true, SnapshotNow, 1, skey);
+            rcscan = systable_beginscan(castDesc, CastOidIndexId, true, NULL, 1, skey);
 
             tup = systable_getnext(rcscan);
 
@@ -2503,7 +2503,7 @@ char* getObjectDescription(const ObjectAddress* object)
             ScanKeyInit(
                 &skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-            adscan = systable_beginscan(attrdefDesc, AttrDefaultOidIndexId, true, SnapshotNow, 1, skey);
+            adscan = systable_beginscan(attrdefDesc, AttrDefaultOidIndexId, true, NULL, 1, skey);
 
             tup = systable_getnext(adscan);
 
@@ -2595,7 +2595,7 @@ char* getObjectDescription(const ObjectAddress* object)
             ScanKeyInit(
                 &skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-            amscan = systable_beginscan(amopDesc, AccessMethodOperatorOidIndexId, true, SnapshotNow, 1, skey);
+            amscan = systable_beginscan(amopDesc, AccessMethodOperatorOidIndexId, true, NULL, 1, skey);
 
             tup = systable_getnext(amscan);
 
@@ -2642,7 +2642,7 @@ char* getObjectDescription(const ObjectAddress* object)
             ScanKeyInit(
                 &skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-            amscan = systable_beginscan(amprocDesc, AccessMethodProcedureOidIndexId, true, SnapshotNow, 1, skey);
+            amscan = systable_beginscan(amprocDesc, AccessMethodProcedureOidIndexId, true, NULL, 1, skey);
 
             tup = systable_getnext(amscan);
 
@@ -2687,7 +2687,7 @@ char* getObjectDescription(const ObjectAddress* object)
             ScanKeyInit(
                 &skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-            rcscan = systable_beginscan(ruleDesc, RewriteOidIndexId, true, SnapshotNow, 1, skey);
+            rcscan = systable_beginscan(ruleDesc, RewriteOidIndexId, true, NULL, 1, skey);
 
             tup = systable_getnext(rcscan);
 
@@ -2717,7 +2717,7 @@ char* getObjectDescription(const ObjectAddress* object)
             ScanKeyInit(
                 &skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-            tgscan = systable_beginscan(trigDesc, TriggerOidIndexId, true, SnapshotNow, 1, skey);
+            tgscan = systable_beginscan(trigDesc, TriggerOidIndexId, true, NULL, 1, skey);
 
             tup = systable_getnext(tgscan);
 
@@ -2885,7 +2885,7 @@ char* getObjectDescription(const ObjectAddress* object)
             ScanKeyInit(
                 &skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-            rcscan = systable_beginscan(defaclrel, DefaultAclOidIndexId, true, SnapshotNow, 1, skey);
+            rcscan = systable_beginscan(defaclrel, DefaultAclOidIndexId, true, NULL, 1, skey);
 
             tup = systable_getnext(rcscan);
 
@@ -2984,7 +2984,7 @@ char* getObjectDescription(const ObjectAddress* object)
                 F_OIDEQ,
                 ObjectIdGetDatum(object->objectId));
 
-            SysScanDesc scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyOidIndex, true, SnapshotNow, 1, scanKey);
+            SysScanDesc scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyOidIndex, true, NULL, 1, scanKey);
 
             HeapTuple tuple = systable_getnext(scanDesc);
             if (HeapTupleIsValid(tuple) == false) {
@@ -3160,7 +3160,7 @@ bool TSConfigurationHasDependentObjects(Oid tsconfoid)
 
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tsconfoid));
 
-    scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Form_pg_depend pg_depend = (Form_pg_depend)GETSTRUCT(tuple);
 
@@ -3227,7 +3227,7 @@ static void findTsDependentObjects(ObjectAddresses* targetObjects, Relation depR
 
         ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(cur->classId));
         ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(cur->objectId));
-        scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+        scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
         while(HeapTupleIsValid(tup = systable_getnext(scan))) {
             Form_pg_depend foundDep = (Form_pg_depend)GETSTRUCT(tup);
             otherObj.classId = foundDep->classid;
diff --git a/src/common/backend/catalog/heap.cpp b/src/common/backend/catalog/heap.cpp
index c23c22265..0b42f9605 100644
--- a/src/common/backend/catalog/heap.cpp
+++ b/src/common/backend/catalog/heap.cpp
@@ -2905,7 +2905,7 @@ static void RelationRemoveInheritance(Oid relid)
 
     ScanKeyInit(&key, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
 
-    scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, SnapshotNow, 1, &key);
+    scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, &key);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan)))
         simple_heap_delete(catalogRelation, &tuple->t_self);
@@ -2963,7 +2963,7 @@ void DeleteAttributeTuples(Oid relid)
     /* Use the index to scan only attributes of the target relation */
     ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
 
-    scan = systable_beginscan(attrel, AttributeRelidNumIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(attrel, AttributeRelidNumIndexId, true, NULL, 1, key);
 
     /* Delete all the matching tuples */
     while ((atttup = systable_getnext(scan)) != NULL)
@@ -2996,7 +2996,7 @@ void DeleteSystemAttributeTuples(Oid relid)
     ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
     ScanKeyInit(&key[1], Anum_pg_attribute_attnum, BTLessEqualStrategyNumber, F_INT2LE, Int16GetDatum(0));
 
-    scan = systable_beginscan(attrel, AttributeRelidNumIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(attrel, AttributeRelidNumIndexId, true, NULL, 2, key);
 
     /* Delete all the matching tuples */
     while ((atttup = systable_getnext(scan)) != NULL)
@@ -3156,7 +3156,7 @@ void RemoveAttrDefault(Oid relid, AttrNumber attnum, DropBehavior behavior, bool
     ScanKeyInit(&scankeys[0], Anum_pg_attrdef_adrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
     ScanKeyInit(&scankeys[1], Anum_pg_attrdef_adnum, BTEqualStrategyNumber, F_INT2EQ, Int16GetDatum(attnum));
 
-    scan = systable_beginscan(attrdef_rel, AttrDefaultIndexId, true, SnapshotNow, 2, scankeys);
+    scan = systable_beginscan(attrdef_rel, AttrDefaultIndexId, true, NULL, 2, scankeys);
 
     /* There should be at most one matching tuple, but we loop anyway */
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
@@ -3204,7 +3204,7 @@ void RemoveAttrDefaultById(Oid attrdefId)
     /* Find the pg_attrdef tuple */
     ScanKeyInit(&scankeys[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(attrdefId));
 
-    scan = systable_beginscan(attrdef_rel, AttrDefaultOidIndexId, true, SnapshotNow, 1, scankeys);
+    scan = systable_beginscan(attrdef_rel, AttrDefaultOidIndexId, true, NULL, 1, scankeys);
 
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
@@ -3945,7 +3945,7 @@ static bool MergeWithExistingConstraint(
         F_OIDEQ,
         ObjectIdGetDatum(RelationGetNamespace(rel)));
 
-    conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, SnapshotNow, 2, skey);
+    conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, NULL, 2, skey);
 
     while (HeapTupleIsValid(tup = systable_getnext(conscan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tup);
@@ -4254,7 +4254,7 @@ void RemoveStatistics(Oid relid, AttrNumber attnum)
     }
 
     pgstatistic = heap_open(StatisticRelationId, RowExclusiveLock);
-    scan = systable_beginscan(pgstatistic, StatisticRelidKindAttnumInhIndexId, true, SnapshotNow, nkeys, key);
+    scan = systable_beginscan(pgstatistic, StatisticRelidKindAttnumInhIndexId, true, NULL, nkeys, key);
 
     /* we must loop even when attnum != 0, in case of inherited stats */
     while (HeapTupleIsValid(tuple = systable_getnext(scan)))
@@ -4269,7 +4269,7 @@ void RemoveStatistics(Oid relid, AttrNumber attnum)
      */
     nkeys = 2;
     pgstatistic = heap_open(StatisticExtRelationId, RowExclusiveLock);
-    scan = systable_beginscan(pgstatistic, StatisticExtRelidKindInhKeyIndexId, true, SnapshotNow, nkeys, key);
+    scan = systable_beginscan(pgstatistic, StatisticExtRelidKindInhKeyIndexId, true, NULL, nkeys, key);
 
     /* we must loop here, in case of inherited stats and extended stats */
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
@@ -4666,7 +4666,7 @@ List* heap_truncate_find_FKs(List* relationIds)
      */
     fkeyRel = heap_open(ConstraintRelationId, AccessShareLock);
 
-    fkeyScan = systable_beginscan(fkeyRel, InvalidOid, false, SnapshotNow, 0, NULL);
+    fkeyScan = systable_beginscan(fkeyRel, InvalidOid, false, NULL, 0, NULL);
 
     while (HeapTupleIsValid(tuple = systable_getnext(fkeyScan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -6750,7 +6750,7 @@ bool FindExistingConstraint(const char* ccname, Relation rel)
         F_OIDEQ,
         ObjectIdGetDatum(RelationGetNamespace(rel)));
 
-    conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, SnapshotNow, 2, skey);
+    conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, NULL, 2, skey);
 
     while (HeapTupleIsValid(tup = systable_getnext(conscan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tup);
diff --git a/src/common/backend/catalog/index.cpp b/src/common/backend/catalog/index.cpp
index 490b2c27b..49754b173 100644
--- a/src/common/backend/catalog/index.cpp
+++ b/src/common/backend/catalog/index.cpp
@@ -4697,7 +4697,7 @@ static void reindexPartIndex(Oid indexId, Oid partOid, bool skip_constraint_chec
 
         ScanKeyInit(&partKey, Anum_pg_partition_indextblid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(partOid));
 
-        partScan = systable_beginscan(partRel, PartitionIndexTableIdIndexId, true, SnapshotNow, 1, &partKey);
+        partScan = systable_beginscan(partRel, PartitionIndexTableIdIndexId, true, NULL, 1, &partKey);
 
         while ((partTuple = systable_getnext(partScan)) != NULL) {
             partForm = (Form_pg_partition)GETSTRUCT(partTuple);
diff --git a/src/common/backend/catalog/namespace.cpp b/src/common/backend/catalog/namespace.cpp
index 636bfc9d4..e5891207a 100644
--- a/src/common/backend/catalog/namespace.cpp
+++ b/src/common/backend/catalog/namespace.cpp
@@ -4737,7 +4737,7 @@ bool checkGroup(Oid relid, bool missing_ok)
              */
             pgxc_group = heap_open(PgxcGroupRelationId, AccessShareLock);
 
-            scan = systable_beginscan(pgxc_group, PgxcGroupGroupNameIndexId, true, SnapshotNow, 0, NULL);
+            scan = systable_beginscan(pgxc_group, PgxcGroupGroupNameIndexId, true, NULL, 0, NULL);
 
             while (HeapTupleIsValid(tuple1 = systable_getnext(scan))) {
                 Form_pgxc_group groupForm = (Form_pgxc_group)GETSTRUCT(tuple1);
diff --git a/src/common/backend/catalog/pg_collation.cpp b/src/common/backend/catalog/pg_collation.cpp
index 6b20ce55b..7cd73ce47 100644
--- a/src/common/backend/catalog/pg_collation.cpp
+++ b/src/common/backend/catalog/pg_collation.cpp
@@ -151,7 +151,7 @@ void RemoveCollationById(Oid collationOid)
 
     ScanKeyInit(&scanKeyData, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(collationOid));
 
-    scandesc = systable_beginscan(rel, CollationOidIndexId, true, SnapshotNow, 1, &scanKeyData);
+    scandesc = systable_beginscan(rel, CollationOidIndexId, true, NULL, 1, &scanKeyData);
 
     tuple = systable_getnext(scandesc);
 
diff --git a/src/common/backend/catalog/pg_constraint.cpp b/src/common/backend/catalog/pg_constraint.cpp
index df389c57c..14648d38a 100644
--- a/src/common/backend/catalog/pg_constraint.cpp
+++ b/src/common/backend/catalog/pg_constraint.cpp
@@ -382,7 +382,7 @@ bool ConstraintNameIsUsed(ConstraintCategory conCat, Oid objId, Oid objNamespace
     ScanKeyInit(
         &skey[1], Anum_pg_constraint_connamespace, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objNamespace));
 
-    conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, SnapshotNow, 2, skey);
+    conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, NULL, 2, skey);
 
     while (HeapTupleIsValid(tup = systable_getnext(conscan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tup);
@@ -464,7 +464,7 @@ char* ChooseConstraintName(const char* name1, const char* name2, const char* lab
                 F_OIDEQ,
                 ObjectIdGetDatum(namespaceid));
 
-            conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, SnapshotNow, 2, skey);
+            conscan = systable_beginscan(conDesc, ConstraintNameNspIndexId, true, NULL, 2, skey);
 
             found = (HeapTupleIsValid(systable_getnext(conscan)));
 
@@ -635,11 +635,11 @@ void AlterConstraintNamespaces(Oid ownerId, Oid oldNspId, Oid newNspId, bool isT
     if (isType) {
         ScanKeyInit(&key[0], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ownerId));
 
-        scan = systable_beginscan(conRel, ConstraintTypidIndexId, true, SnapshotNow, 1, key);
+        scan = systable_beginscan(conRel, ConstraintTypidIndexId, true, NULL, 1, key);
     } else {
         ScanKeyInit(&key[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ownerId));
 
-        scan = systable_beginscan(conRel, ConstraintRelidIndexId, true, SnapshotNow, 1, key);
+        scan = systable_beginscan(conRel, ConstraintRelidIndexId, true, NULL, 1, key);
     }
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
@@ -721,7 +721,7 @@ Oid get_relation_constraint_oid(Oid relid, const char* conname, bool missing_ok)
 
     ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
 
-    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -770,7 +770,7 @@ Oid get_domain_constraint_oid(Oid typid, const char* conname, bool missing_ok)
 
     ScanKeyInit(&skey[0], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(typid));
 
-    scan = systable_beginscan(pg_constraint, ConstraintTypidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_constraint, ConstraintTypidIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -824,7 +824,7 @@ bool check_functional_grouping(Oid relid, Index varno, Index varlevelsup, List*
 
     ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
 
-    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -914,7 +914,7 @@ List* get_parse_dependency_rel_list(List* conids)
         Oid conid = lfirst_oid(lc);
         ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, conid);
 
-        scan = systable_beginscan(pg_constraint, ConstraintOidIndexId, true, SnapshotNow, 1, skey);
+        scan = systable_beginscan(pg_constraint, ConstraintOidIndexId, true, NULL, 1, skey);
 
         /* Only one record should be qualified, and get the relid */
         if (HeapTupleIsValid(tuple = systable_getnext(scan))) {
diff --git a/src/common/backend/catalog/pg_db_role_setting.cpp b/src/common/backend/catalog/pg_db_role_setting.cpp
index 9be3da01e..16b9437f2 100644
--- a/src/common/backend/catalog/pg_db_role_setting.cpp
+++ b/src/common/backend/catalog/pg_db_role_setting.cpp
@@ -63,7 +63,7 @@ void AlterSetting(Oid databaseid, Oid roleid, VariableSetStmt* setstmt)
     ScanKeyInit(
         &scankey[0], Anum_pg_db_role_setting_setdatabase, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(databaseid));
     ScanKeyInit(&scankey[1], Anum_pg_db_role_setting_setrole, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(roleid));
-    scan = systable_beginscan(rel, DbRoleSettingDatidRolidIndexId, true, SnapshotNow, 2, scankey);
+    scan = systable_beginscan(rel, DbRoleSettingDatidRolidIndexId, true, NULL, 2, scankey);
     tuple = systable_getnext(scan);
 
     /*
@@ -238,7 +238,7 @@ void ApplySetting(Oid databaseid, Oid roleid, Relation relsetting, GucSource sou
         &keys[0], Anum_pg_db_role_setting_setdatabase, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(databaseid));
     ScanKeyInit(&keys[1], Anum_pg_db_role_setting_setrole, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(roleid));
 
-    scan = systable_beginscan(relsetting, DbRoleSettingDatidRolidIndexId, true, SnapshotNow, 2, keys);
+    scan = systable_beginscan(relsetting, DbRoleSettingDatidRolidIndexId, true, NULL, 2, keys);
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         bool isnull = false;
         Datum datum;
diff --git a/src/common/backend/catalog/pg_depend.cpp b/src/common/backend/catalog/pg_depend.cpp
index 3618a4423..35ed5310e 100644
--- a/src/common/backend/catalog/pg_depend.cpp
+++ b/src/common/backend/catalog/pg_depend.cpp
@@ -250,7 +250,7 @@ long deleteDependencyRecordsFor(Oid classId, Oid objectId, bool skipExtensionDep
     ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(classId));
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objectId));
 
-    scan = systable_beginscan(depRel, DependDependerIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         if (skipExtensionDeps && ((Form_pg_depend)GETSTRUCT(tup))->deptype == DEPENDENCY_EXTENSION)
@@ -291,7 +291,7 @@ long deleteDependencyRecordsForClass(Oid classId, Oid objectId, Oid refclassId,
     ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(classId));
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objectId));
 
-    scan = systable_beginscan(depRel, DependDependerIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend depform = (Form_pg_depend)GETSTRUCT(tup);
@@ -361,7 +361,7 @@ long changeDependencyFor(Oid classId, Oid objectId, Oid refClassId, Oid oldRefOb
     ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(classId));
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objectId));
 
-    scan = systable_beginscan(depRel, DependDependerIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         Form_pg_depend depform = (Form_pg_depend)GETSTRUCT(tup);
@@ -420,7 +420,7 @@ static bool isObjectPinned(const ObjectAddress* object, Relation rel)
 
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
 
-    scan = systable_beginscan(rel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(rel, DependReferenceIndexId, true, NULL, 2, key);
 
     /*
      * Since we won't generate additional pg_depend entries for pinned
@@ -469,7 +469,7 @@ Oid getExtensionOfObject(Oid classId, Oid objectId)
     ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(classId));
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objectId));
 
-    scan = systable_beginscan(depRel, DependDependerIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         Form_pg_depend depform = (Form_pg_depend)GETSTRUCT(tup);
@@ -511,7 +511,7 @@ bool sequenceIsOwned(Oid seqId, Oid* tableId, int32* colId)
     ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId));
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(seqId));
 
-    scan = systable_beginscan(depRel, DependDependerIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         Form_pg_depend depform = (Form_pg_depend)GETSTRUCT(tup);
@@ -559,7 +559,7 @@ List* getOwnedSequences(Oid relid, List* attrList)
         &key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId));
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
 
-    scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend deprec = (Form_pg_depend)GETSTRUCT(tup);
@@ -612,7 +612,7 @@ Oid get_constraint_index(Oid constraintId)
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(constraintId));
     ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(0));
 
-    scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 3, key);
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 3, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend deprec = (Form_pg_depend)GETSTRUCT(tup);
@@ -657,7 +657,7 @@ Oid get_index_constraint(Oid indexId)
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(indexId));
     ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(0));
 
-    scan = systable_beginscan(depRel, DependDependerIndexId, true, SnapshotNow, 3, key);
+    scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 3, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend deprec = (Form_pg_depend)GETSTRUCT(tup);
diff --git a/src/common/backend/catalog/pg_enum.cpp b/src/common/backend/catalog/pg_enum.cpp
index 6f51612b1..525bdb449 100644
--- a/src/common/backend/catalog/pg_enum.cpp
+++ b/src/common/backend/catalog/pg_enum.cpp
@@ -145,7 +145,7 @@ void EnumValuesDelete(Oid enumTypeOid)
 
     ScanKeyInit(&key[0], Anum_pg_enum_enumtypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(enumTypeOid));
 
-    scan = systable_beginscan(pg_enum, EnumTypIdLabelIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(pg_enum, EnumTypIdLabelIndexId, true, NULL, 1, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         simple_heap_delete(pg_enum, &tup->t_self);
diff --git a/src/common/backend/catalog/pg_hashbucket.cpp b/src/common/backend/catalog/pg_hashbucket.cpp
index 66db22b3f..c9302ce6e 100644
--- a/src/common/backend/catalog/pg_hashbucket.cpp
+++ b/src/common/backend/catalog/pg_hashbucket.cpp
@@ -389,7 +389,7 @@ Oid searchHashBucketByBucketid(oidvector *bucketlist, Oid bucketid)
                 BTEqualStrategyNumber, F_INT4EQ,
                 Int32GetDatum(bucketlist->dim1));
 
-    scan = systable_beginscan(pg_hashbucket, HashBucketBidIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(pg_hashbucket, HashBucketBidIndexId, true, NULL, 3, key);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Datum      bucketDatum;
         bool      isnull = false;
@@ -440,7 +440,7 @@ text* searchMergeListByRelid(Oid reloid, bool *find, bool retresult)
                 BTEqualStrategyNumber, F_OIDEQ,
                 ObjectIdGetDatum(reloid));
 
-    scan = systable_beginscan(pgxc_class_rel, PgxcClassPgxcRelIdIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(pgxc_class_rel, PgxcClassPgxcRelIdIndexId, true, NULL, 1, key);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Datum      pgxcDatum;
         bool      isnull = false;
diff --git a/src/common/backend/catalog/pg_inherits.cpp b/src/common/backend/catalog/pg_inherits.cpp
index 5d28922a0..81742cefe 100644
--- a/src/common/backend/catalog/pg_inherits.cpp
+++ b/src/common/backend/catalog/pg_inherits.cpp
@@ -73,7 +73,7 @@ List* find_inheritance_children(Oid parentrelId, LOCKMODE lockmode)
 
     ScanKeyInit(&key[0], Anum_pg_inherits_inhparent, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(parentrelId));
 
-    scan = systable_beginscan(relation, InheritsParentIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(relation, InheritsParentIndexId, true, NULL, 1, key);
 
     while ((inheritsTuple = systable_getnext(scan)) != NULL) {
         inhrelid = ((Form_pg_inherits)GETSTRUCT(inheritsTuple))->inhrelid;
@@ -297,7 +297,7 @@ bool typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId)
 
         ScanKeyInit(&skey, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(this_relid));
 
-        inhscan = systable_beginscan(inhrel, InheritsRelidSeqnoIndexId, true, SnapshotNow, 1, &skey);
+        inhscan = systable_beginscan(inhrel, InheritsRelidSeqnoIndexId, true, NULL, 1, &skey);
 
         while ((inhtup = systable_getnext(inhscan)) != NULL) {
             Form_pg_inherits inh = (Form_pg_inherits)GETSTRUCT(inhtup);
diff --git a/src/common/backend/catalog/pg_largeobject.cpp b/src/common/backend/catalog/pg_largeobject.cpp
index b16feb5c8..ea3785dce 100644
--- a/src/common/backend/catalog/pg_largeobject.cpp
+++ b/src/common/backend/catalog/pg_largeobject.cpp
@@ -95,7 +95,7 @@ void LargeObjectDrop(Oid loid)
      */
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(loid));
 
-    scan = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, NULL, 1, skey);
 
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
@@ -110,7 +110,7 @@ void LargeObjectDrop(Oid loid)
      */
     ScanKeyInit(&skey[0], Anum_pg_largeobject_loid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(loid));
 
-    scan = systable_beginscan(pg_largeobject, LargeObjectLOidPNIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_largeobject, LargeObjectLOidPNIndexId, true, NULL, 1, skey);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         simple_heap_delete(pg_largeobject, &tuple->t_self);
     }
@@ -140,7 +140,7 @@ void LargeObjectAlterOwner(Oid loid, Oid newOwnerId)
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(loid));
 
-    scan = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, NULL, 1, skey);
 
     oldtup = systable_getnext(scan);
     if (!HeapTupleIsValid(oldtup))
@@ -232,7 +232,7 @@ bool LargeObjectExists(Oid loid)
 
     pg_lo_meta = heap_open(LargeObjectMetadataRelationId, AccessShareLock);
 
-    sd = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, SnapshotNow, 1, skey);
+    sd = systable_beginscan(pg_lo_meta, LargeObjectMetadataOidIndexId, true, NULL, 1, skey);
 
     tuple = systable_getnext(sd);
     if (HeapTupleIsValid(tuple))
diff --git a/src/common/backend/catalog/pg_partition.cpp b/src/common/backend/catalog/pg_partition.cpp
index ca424a4cd..72fc0627d 100644
--- a/src/common/backend/catalog/pg_partition.cpp
+++ b/src/common/backend/catalog/pg_partition.cpp
@@ -694,7 +694,7 @@ List* getPartitionObjectIdList(Oid relid, char relkind)
     ScanKeyInit(&key[0], Anum_pg_partition_parttype, BTEqualStrategyNumber, F_CHAREQ, CharGetDatum(relkind));
     ScanKeyInit(&key[1], Anum_pg_partition_parentid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
 
-    scan = systable_beginscan(relation, PartitionParentOidIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(relation, PartitionParentOidIndexId, true, NULL, 2, key);
     while (HeapTupleIsValid((tuple = systable_getnext(scan)))) {
         partitionid = HeapTupleGetOid(tuple);
 
@@ -728,7 +728,7 @@ List* searchPartitionIndexesByblid(Oid blid)
 
     ScanKeyInit(&key[0], Anum_pg_partition_indextblid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(blid));
 
-    scan = systable_beginscan(partRel, PartitionIndexTableIdIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(partRel, PartitionIndexTableIdIndexId, true, NULL, 1, key);
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         dtp = heap_copytuple(tup);
         l = lappend(l, dtp);
@@ -761,7 +761,18 @@ List* searchPgPartitionByParentId(char parttype, Oid parentId)
     ScanKeyInit(&key[0], Anum_pg_partition_parttype, BTEqualStrategyNumber, F_CHAREQ, CharGetDatum(parttype));
     ScanKeyInit(&key[1], Anum_pg_partition_parentid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(parentId));
 
-    scan = systable_beginscan(pg_partition, PartitionParentOidIndexId, true, SnapshotNow, 2, key);
+    /*
+     * The caller might need a tuple that's newer than the one the historic
+     * snapshot; currently the only case requiring to do so is looking up the
+     * relfilenode of non mapped system relations during decoding.
+     */
+    Snapshot snapshot = NULL;
+    snapshot = SnapshotNow;
+    if (HistoricSnapshotActive()) {
+        snapshot = GetCatalogSnapshot();
+    }
+
+    scan = systable_beginscan(pg_partition, PartitionParentOidIndexId, true, snapshot, 2, key);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         dtuple = heap_copytuple(tuple);
 
diff --git a/src/common/backend/catalog/pg_range.cpp b/src/common/backend/catalog/pg_range.cpp
index 9f7e3cad3..d3697b787 100644
--- a/src/common/backend/catalog/pg_range.cpp
+++ b/src/common/backend/catalog/pg_range.cpp
@@ -116,7 +116,7 @@ void RangeDelete(Oid rangeTypeOid)
 
     ScanKeyInit(&key[0], Anum_pg_range_rngtypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(rangeTypeOid));
 
-    scan = systable_beginscan(pg_range, RangeTypidIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(pg_range, RangeTypidIndexId, true, NULL, 1, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         simple_heap_delete(pg_range, &tup->t_self);
diff --git a/src/common/backend/catalog/pg_shdepend.cpp b/src/common/backend/catalog/pg_shdepend.cpp
index 633b3691f..c39463bb4 100644
--- a/src/common/backend/catalog/pg_shdepend.cpp
+++ b/src/common/backend/catalog/pg_shdepend.cpp
@@ -212,7 +212,7 @@ static void shdepChangeDep(Relation sdepRel, Oid classid, Oid objid, int32 objsu
     ScanKeyInit(&key[2], Anum_pg_shdepend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objid));
     ScanKeyInit(&key[3], Anum_pg_shdepend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(objsubid));
 
-    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, SnapshotNow, 4, key);
+    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, NULL, 4, key);
 
     while ((scantup = systable_getnext(scan)) != NULL) {
         /* Ignore if not of the target dependency type */
@@ -478,7 +478,7 @@ SysScanDesc initAndGetScanByRefId(Relation sdepRel, Oid classId, Oid objectId)
     ScanKeyInit(&key[0], Anum_pg_shdepend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(classId));
     ScanKeyInit(&key[1], Anum_pg_shdepend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(objectId));
 
-    return systable_beginscan(sdepRel, SharedDependReferenceIndexId, true, SnapshotNow, NumberOfReferenceKey, key);
+    return systable_beginscan(sdepRel, SharedDependReferenceIndexId, true, NULL, NumberOfReferenceKey, key);
 }
 
 SysScanDesc initAndGetScanByDependerIndexId(
@@ -511,7 +511,7 @@ SysScanDesc initAndGetScanByDependerIndexId(
         }
     }
 
-    return systable_beginscan(sdepRel, SharedDependDependerIndexId, true, SnapshotNow, maxAttributeId, key);
+    return systable_beginscan(sdepRel, SharedDependDependerIndexId, true, NULL, maxAttributeId, key);
 }
 
 /*
@@ -708,7 +708,7 @@ void copyTemplateDependencies(Oid templateDbId, Oid newDbId)
     /* Scan all entries with dbid = templateDbId */
     ScanKeyInit(&key[0], Anum_pg_shdepend_dbid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(templateDbId));
 
-    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, NULL, 1, key);
 
     /* Set up to copy the tuples except for inserting newDbId */
     rc = memset_s(values, sizeof(values), 0, sizeof(values));
@@ -788,7 +788,7 @@ void dropDatabaseDependencies(Oid databaseId)
      */
     ScanKeyInit(&key[0], Anum_pg_shdepend_dbid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(databaseId));
     /* We leave the other index fields unspecified */
-    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, NULL, 1, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
 #ifdef ENABLE_MOT
@@ -918,7 +918,7 @@ static void shdepDropDependency(Relation sdepRel, Oid classId, Oid objectId, int
         nkeys = 4;
     }
 
-    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, SnapshotNow, nkeys, key);
+    scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true, NULL, nkeys, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_shdepend shdepForm = (Form_pg_shdepend)GETSTRUCT(tup);
@@ -1410,7 +1410,7 @@ bool CheckDependencyOnRespool(Oid classId, Oid refobjectId, List** foundlist, bo
         &key[0], Anum_pg_shdepend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ResourcePoolRelationId));
     ScanKeyInit(&key[1], Anum_pg_shdepend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(refobjectId));
 
-    scan = systable_beginscan(sdepRel, SharedDependReferenceIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(sdepRel, SharedDependReferenceIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_shdepend sdepForm = (Form_pg_shdepend)GETSTRUCT(tup);
diff --git a/src/common/backend/catalog/pgxc_class.cpp b/src/common/backend/catalog/pgxc_class.cpp
index 837c7a7dd..3b2d5f8c6 100644
--- a/src/common/backend/catalog/pgxc_class.cpp
+++ b/src/common/backend/catalog/pgxc_class.cpp
@@ -425,7 +425,7 @@ bool RelationRedisCheck(Relation rel)
         &skey, Anum_pgxc_class_pcrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
 
     pcrel = heap_open(PgxcClassRelationId, AccessShareLock);
-    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, SnapshotNow, 1, &skey);
+    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, NULL, 1, &skey);
     htup = systable_getnext(pcscan);
     if (!HeapTupleIsValid(htup)) {
         /* Assume local relation only */
diff --git a/src/common/backend/client_logic/client_logic.cpp b/src/common/backend/client_logic/client_logic.cpp
index 724017017..6b256b915 100644
--- a/src/common/backend/client_logic/client_logic.cpp
+++ b/src/common/backend/client_logic/client_logic.cpp
@@ -992,7 +992,7 @@ void remove_cmk_args_by_id(Oid id)
     HeapTuple tuple;
 
     ScanKeyInit(&scankey, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(id));
-    scan = systable_beginscan(ce_rel, ClientLogicGlobalSettingsArgsOidIndexId, true, SnapshotNow, 1, &scankey);
+    scan = systable_beginscan(ce_rel, ClientLogicGlobalSettingsArgsOidIndexId, true, NULL, 1, &scankey);
 
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
@@ -1010,7 +1010,7 @@ void remove_cek_args_by_id(Oid id)
     HeapTuple tuple;
 
     ScanKeyInit(&scankey, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(id));
-    scan = systable_beginscan(ce_rel, ClientLogicColumnSettingsArgsOidIndexId, true, SnapshotNow, 1, &scankey);
+    scan = systable_beginscan(ce_rel, ClientLogicColumnSettingsArgsOidIndexId, true, NULL, 1, &scankey);
 
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
@@ -1032,7 +1032,7 @@ void get_global_setting_description(StringInfo buffer, const ObjectAddress *obje
     cmKeys = heap_open(ClientLogicGlobalSettingsId, AccessShareLock);
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
-    rcscan = systable_beginscan(cmKeys, ClientLogicGlobalSettingsOidIndexId, true, SnapshotNow, 1, skey);
+    rcscan = systable_beginscan(cmKeys, ClientLogicGlobalSettingsOidIndexId, true, NULL, 1, skey);
     tup = systable_getnext(rcscan);
     if (!HeapTupleIsValid(tup)) {
         systable_endscan(rcscan);
@@ -1057,7 +1057,7 @@ void get_column_setting_description(StringInfo buffer, const ObjectAddress *obje
     column_setting_rel = heap_open(ClientLogicColumnSettingsId, AccessShareLock);
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
-    rcscan = systable_beginscan(column_setting_rel, ClientLogicColumnSettingsOidIndexId, true, SnapshotNow, 1, skey);
+    rcscan = systable_beginscan(column_setting_rel, ClientLogicColumnSettingsOidIndexId, true, NULL, 1, skey);
     tup = systable_getnext(rcscan);
     if (!HeapTupleIsValid(tup)) {
         systable_endscan(rcscan);
@@ -1105,7 +1105,7 @@ void get_global_setting_args_description(StringInfo buffer, const ObjectAddress
     rel = heap_open(ClientLogicGlobalSettingsArgsId, AccessShareLock);
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
-    rcscan = systable_beginscan(rel, ClientLogicGlobalSettingsArgsOidIndexId, true, SnapshotNow, 1, skey);
+    rcscan = systable_beginscan(rel, ClientLogicGlobalSettingsArgsOidIndexId, true, NULL, 1, skey);
     tup = systable_getnext(rcscan);
     if (!HeapTupleIsValid(tup)) {
         systable_endscan(rcscan);
@@ -1129,7 +1129,7 @@ void get_column_setting_args_description(StringInfo buffer, const ObjectAddress
     rel = heap_open(ClientLogicColumnSettingsArgsId, AccessShareLock);
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(object->objectId));
-    rcscan = systable_beginscan(rel, ClientLogicColumnSettingsArgsOidIndexId, true, SnapshotNow, 1, skey);
+    rcscan = systable_beginscan(rel, ClientLogicColumnSettingsArgsOidIndexId, true, NULL, 1, skey);
     tup = systable_getnext(rcscan);
     if (!HeapTupleIsValid(tup)) {
         systable_endscan(rcscan);
diff --git a/src/common/backend/parser/analyze.cpp b/src/common/backend/parser/analyze.cpp
index 623eb91f4..cf5d21947 100644
--- a/src/common/backend/parser/analyze.cpp
+++ b/src/common/backend/parser/analyze.cpp
@@ -3972,7 +3972,7 @@ static bool is_rel_child_of_rel(RangeTblEntry* child_rte, RangeTblEntry* parent_
     /* Scan pg_inherits and get all the subclass OIDs one by one. */
     relation = heap_open(InheritsRelationId, AccessShareLock);
     ScanKeyInit(&key[0], Anum_pg_inherits_inhparent, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(parentOID));
-    scan = systable_beginscan(relation, InheritsParentIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(relation, InheritsParentIndexId, true, NULL, 1, key);
 
     while ((inheritsTuple = systable_getnext(scan)) != NULL) {
         inhrelid = ((Form_pg_inherits)GETSTRUCT(inheritsTuple))->inhrelid;
diff --git a/src/common/backend/pgxc_single/locator/locator.cpp b/src/common/backend/pgxc_single/locator/locator.cpp
index b7fc1e302..3f5562059 100644
--- a/src/common/backend/pgxc_single/locator/locator.cpp
+++ b/src/common/backend/pgxc_single/locator/locator.cpp
@@ -963,7 +963,7 @@ void RelationBuildLocator(Relation rel)
         &skey, Anum_pgxc_class_pcrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
 
     pcrel = heap_open(PgxcClassRelationId, AccessShareLock);
-    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, SnapshotNow, 1, &skey);
+    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, NULL, 1, &skey);
     htup = systable_getnext(pcscan);
     if (!HeapTupleIsValid(htup)) {
         /* Assume local relation only */
diff --git a/src/common/backend/pgxc_single/nodemgr/groupmgr.cpp b/src/common/backend/pgxc_single/nodemgr/groupmgr.cpp
index 2ca428f80..c1d0dfa95 100644
--- a/src/common/backend/pgxc_single/nodemgr/groupmgr.cpp
+++ b/src/common/backend/pgxc_single/nodemgr/groupmgr.cpp
@@ -3367,7 +3367,7 @@ char* PgxcGroupGetFirstLogicCluster()
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTGreaterStrategyNumber, F_OIDGT, ObjectIdGetDatum(0));
 
-    scan = systable_beginscan(pgxc_group_rel, PgxcGroupOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pgxc_group_rel, PgxcGroupOidIndexId, true, NULL, 1, skey);
 
     while ((tup = systable_getnext(scan)) != NULL) {
         group_kind = get_group_kind(tup);
@@ -4614,7 +4614,7 @@ List* PgxcGroupGetLogicClusterList(Bitmapset* nodeids)
     }
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTGreaterStrategyNumber, F_OIDGT, ObjectIdGetDatum(0));
-    scan = systable_beginscan(pgxc_group_rel, PgxcGroupOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pgxc_group_rel, PgxcGroupOidIndexId, true, NULL, 1, skey);
 
     while ((tup = systable_getnext(scan)) != NULL) {
         Oid group_oid = HeapTupleGetOid(tup);
diff --git a/src/common/backend/pgxc_single/nodemgr/nodemgr.cpp b/src/common/backend/pgxc_single/nodemgr/nodemgr.cpp
index a475cd5a1..300ab74d0 100644
--- a/src/common/backend/pgxc_single/nodemgr/nodemgr.cpp
+++ b/src/common/backend/pgxc_single/nodemgr/nodemgr.cpp
@@ -1174,7 +1174,7 @@ void PgxcNodeAlter(AlterNodeStmt* stmt)
 
         HeapTuple tmptup;
         TupleDesc pg_node_dsc = RelationGetDescr(rel);
-        SysScanDesc scan = systable_beginscan(rel, InvalidOid, false, SnapshotNow, 0, NULL);
+        SysScanDesc scan = systable_beginscan(rel, InvalidOid, false, NULL, 0, NULL);
         while (HeapTupleIsValid((tmptup = systable_getnext(scan)))) {
             bool isnull = true;
             Oid scanoid = HeapTupleGetOid(tmptup);
diff --git a/src/common/backend/pgxc_single/pool/execRemote.cpp b/src/common/backend/pgxc_single/pool/execRemote.cpp
index fb6c839c9..119081c0d 100644
--- a/src/common/backend/pgxc_single/pool/execRemote.cpp
+++ b/src/common/backend/pgxc_single/pool/execRemote.cpp
@@ -8210,7 +8210,7 @@ bool IsInheritor(Oid relid)
 
     pginherits = heap_open(InheritsRelationId, AccessShareLock);
     ScanKeyInit(&key[0], Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, relid);
-    scan = systable_beginscan(pginherits, InheritsRelidSeqnoIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(pginherits, InheritsRelidSeqnoIndexId, true, NULL, 1, key);
     if (HeapTupleIsValid(systable_getnext(scan))) {
         ret = true;
     }
diff --git a/src/common/backend/utils/adt/clientlogicsettings.cpp b/src/common/backend/utils/adt/clientlogicsettings.cpp
index f66a0a673..4181c8371 100644
--- a/src/common/backend/utils/adt/clientlogicsettings.cpp
+++ b/src/common/backend/utils/adt/clientlogicsettings.cpp
@@ -82,7 +82,7 @@ Datum globalsettingin(PG_FUNCTION_ARGS)
             CStringGetDatum(key_name_or_oid));
 
         hdesc = heap_open(ClientLogicGlobalSettingsId, AccessShareLock);
-        sysscan = systable_beginscan(hdesc, ClientLogicGlobalSettingsNameIndexId, true, SnapshotNow, 1, skey);
+        sysscan = systable_beginscan(hdesc, ClientLogicGlobalSettingsNameIndexId, true, NULL, 1, skey);
 
         while (HeapTupleIsValid(tuple = systable_getnext(sysscan))) {
             result = Oid HeapTupleGetOid(tuple);
@@ -166,7 +166,7 @@ Datum columnsettingin(PG_FUNCTION_ARGS)
             CStringGetDatum(key_name_or_oid));
 
         hdesc = heap_open(ClientLogicColumnSettingsId, AccessShareLock);
-        sysscan = systable_beginscan(hdesc, ClientLogicColumnSettingsNameIndexId, true, SnapshotNow, 1, skey);
+        sysscan = systable_beginscan(hdesc, ClientLogicColumnSettingsNameIndexId, true, NULL, 1, skey);
 
         while (HeapTupleIsValid(tuple = systable_getnext(sysscan))) {
             result = Oid HeapTupleGetOid(tuple);
diff --git a/src/common/backend/utils/adt/dbsize.cpp b/src/common/backend/utils/adt/dbsize.cpp
index 18e668685..41c9a4355 100644
--- a/src/common/backend/utils/adt/dbsize.cpp
+++ b/src/common/backend/utils/adt/dbsize.cpp
@@ -518,7 +518,7 @@ static double calculate_source_database_size()
     /*scan the pg_class to fetch the reltuples of every relation.*/
     class_rel = heap_open(RelationRelationId, AccessShareLock);
     pg_class_tuple_desc = class_rel->rd_att;
-    scan = systable_beginscan(class_rel, InvalidOid, false, SnapshotNow, 0, NULL);
+    scan = systable_beginscan(class_rel, InvalidOid, false, NULL, 0, NULL);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         tuple_class = (Form_pg_class)GETSTRUCT(tuple);
         Oid relid = HeapTupleHeaderGetOid(tuple->t_data);
diff --git a/src/common/backend/utils/adt/extended_statistics.cpp b/src/common/backend/utils/adt/extended_statistics.cpp
index 00e27dfa2..eaf9ab977 100644
--- a/src/common/backend/utils/adt/extended_statistics.cpp
+++ b/src/common/backend/utils/adt/extended_statistics.cpp
@@ -921,7 +921,7 @@ List* es_explore_declared_stats(Oid relid, VacuumStmt* vacstmt, bool inh)
     ScanKeyInit(&key[2], Anum_pg_statistic_ext_stainherit, BTEqualStrategyNumber, F_BOOLEQ, BoolGetDatum(inh));
 
     Relation relation = heap_open(StatisticExtRelationId, AccessShareLock);
-    SysScanDesc scan = systable_beginscan(relation, StatisticExtRelidKindInhKeyIndexId, true, SnapshotNow, 3, key);
+    SysScanDesc scan = systable_beginscan(relation, StatisticExtRelidKindInhKeyIndexId, true, NULL, 3, key);
 
     List* es_list = NIL;
     for (HeapTuple tuple = NULL; NULL != (tuple = systable_getnext(scan));) {
@@ -1114,7 +1114,7 @@ static List* es_search_extended_statistics(
 
     Relation relation = heap_open(StatisticExtRelationId, AccessShareLock);
     SysScanDesc scan =
-        systable_beginscan(relation, StatisticExtRelidKindInhKeyIndexId, true, SnapshotNow, num_key, key);
+        systable_beginscan(relation, StatisticExtRelidKindInhKeyIndexId, true, NULL, num_key, key);
 
     int count = 0;
     for (HeapTuple tuple = NULL; NULL != (tuple = systable_getnext(scan));) {
diff --git a/src/common/backend/utils/adt/regproc.cpp b/src/common/backend/utils/adt/regproc.cpp
index 360cd2efc..815b23a89 100644
--- a/src/common/backend/utils/adt/regproc.cpp
+++ b/src/common/backend/utils/adt/regproc.cpp
@@ -56,7 +56,7 @@ static Datum regprocin_booststrap(char* procname)
     ScanKeyInit(&skey[0], Anum_pg_proc_proname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(procname));
 
     hdesc = heap_open(ProcedureRelationId, AccessShareLock);
-    sysscan = systable_beginscan(hdesc, ProcedureNameArgsNspIndexId, true, SnapshotNow, 1, skey);
+    sysscan = systable_beginscan(hdesc, ProcedureNameArgsNspIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(tuple = systable_getnext(sysscan))) {
         result = (RegProcedure)HeapTupleGetOid(tuple);
@@ -416,7 +416,7 @@ Datum regoperin(PG_FUNCTION_ARGS)
             &skey[0], Anum_pg_operator_oprname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(opr_name_or_oid));
 
         hdesc = heap_open(OperatorRelationId, AccessShareLock);
-        sysscan = systable_beginscan(hdesc, OperatorNameNspIndexId, true, SnapshotNow, 1, skey);
+        sysscan = systable_beginscan(hdesc, OperatorNameNspIndexId, true, NULL, 1, skey);
 
         while (HeapTupleIsValid(tuple = systable_getnext(sysscan))) {
             result = HeapTupleGetOid(tuple);
@@ -730,7 +730,7 @@ Datum regclassin(PG_FUNCTION_ARGS)
             &skey[0], Anum_pg_class_relname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(class_name_or_oid));
 
         hdesc = heap_open(RelationRelationId, AccessShareLock);
-        sysscan = systable_beginscan(hdesc, ClassNameNspIndexId, true, SnapshotNow, 1, skey);
+        sysscan = systable_beginscan(hdesc, ClassNameNspIndexId, true, NULL, 1, skey);
 
         if (HeapTupleIsValid(tuple = systable_getnext(sysscan)))
             result = HeapTupleGetOid(tuple);
@@ -877,7 +877,7 @@ Datum regtypein(PG_FUNCTION_ARGS)
         ScanKeyInit(&skey[0], Anum_pg_type_typname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(typ_name_or_oid));
 
         hdesc = heap_open(TypeRelationId, AccessShareLock);
-        sysscan = systable_beginscan(hdesc, TypeNameNspIndexId, true, SnapshotNow, 1, skey);
+        sysscan = systable_beginscan(hdesc, TypeNameNspIndexId, true, NULL, 1, skey);
 
         if (HeapTupleIsValid(tuple = systable_getnext(sysscan)))
             result = HeapTupleGetOid(tuple);
diff --git a/src/common/backend/utils/adt/ruleutils.cpp b/src/common/backend/utils/adt/ruleutils.cpp
index 9d0a669ac..7dd76fc10 100644
--- a/src/common/backend/utils/adt/ruleutils.cpp
+++ b/src/common/backend/utils/adt/ruleutils.cpp
@@ -940,7 +940,7 @@ static void get_table_partitiondef(StringInfo query, StringInfo buf, Oid tableoi
     ScanKeyInit(&key[0], Anum_pg_partition_parttype, BTEqualStrategyNumber, F_CHAREQ, CharGetDatum(relkind));
     ScanKeyInit(&key[1], Anum_pg_partition_parentid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableoid));
 
-    scan = systable_beginscan(relation, PartitionParentOidIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(relation, PartitionParentOidIndexId, true, NULL, 2, key);
     while (HeapTupleIsValid((tuple = systable_getnext(scan)))) {
         int2vector* partVec = NULL;
         Datum datum = SysCacheGetAttr(PARTRELID, tuple, Anum_pg_partition_partkey, &isnull);
@@ -1208,7 +1208,7 @@ static int get_table_attribute(
                 ScanKeyInit(
                     &skey[0], Anum_pg_attrdef_adrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableoid));
 
-                adscan = systable_beginscan(attrdefDesc, AttrDefaultIndexId, true, SnapshotNow, 1, skey);
+                adscan = systable_beginscan(attrdefDesc, AttrDefaultIndexId, true, NULL, 1, skey);
 
                 while (HeapTupleIsValid(tup = systable_getnext(adscan))) {
                     attrdef = (Form_pg_attrdef)GETSTRUCT(tup);
@@ -1252,7 +1252,7 @@ char* printDistributeKey(Oid relOid)
     ScanKeyInit(&skey, Anum_pgxc_class_pcrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relOid));
 
     pcrel = heap_open(PgxcClassRelationId, AccessShareLock);
-    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, SnapshotNow, 1, &skey);
+    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, NULL, 1, &skey);
     htup = systable_getnext(pcscan);
 
     if (!HeapTupleIsValid(htup)) {
@@ -1551,7 +1551,7 @@ static void get_foreign_constraint_info(StringInfo buf, Oid tableoid, const char
 
     ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableoid));
 
-    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -1606,7 +1606,7 @@ static void get_index_list_info(Oid tableoid, StringInfo buf, const char* relnam
     ScanKeyInit(&skey, Anum_pg_index_indrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableoid));
 
     indrel = heap_open(IndexRelationId, AccessShareLock);
-    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, SnapshotNow, 1, &skey);
+    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid(htup = systable_getnext(indscan))) {
         Form_pg_index index = (Form_pg_index)GETSTRUCT(htup);
@@ -1899,7 +1899,7 @@ static void get_table_alter_info(
 
         ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableoid));
 
-        scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+        scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, NULL, 1, skey);
 
         while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
             Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -2187,7 +2187,7 @@ static char* pg_get_tabledef_worker(Oid tableoid)
 
     ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableoid));
 
-    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_constraint, ConstraintRelidIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -2319,7 +2319,7 @@ static char* pg_get_triggerdef_worker(Oid trigid, bool pretty)
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(trigid));
 
-    tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true, SnapshotNow, 1, skey);
+    tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true, NULL, 1, skey);
 
     ht_trig = systable_getnext(tgscan);
 
@@ -3441,7 +3441,7 @@ Datum pg_get_serial_sequence(PG_FUNCTION_ARGS)
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableOid));
     ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(attnum));
 
-    scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 3, key);
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 3, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend deprec = (Form_pg_depend)GETSTRUCT(tup);
@@ -11136,7 +11136,7 @@ Datum getDistributeKey(PG_FUNCTION_ARGS)
     ScanKeyInit(&skey, Anum_pgxc_class_pcrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relOid));
 
     pcrel = heap_open(PgxcClassRelationId, AccessShareLock);
-    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, SnapshotNow, 1, &skey);
+    pcscan = systable_beginscan(pcrel, PgxcClassPgxcRelIdIndexId, true, NULL, 1, &skey);
     htup = systable_getnext(pcscan);
 
     if (!HeapTupleIsValid(htup)) {
diff --git a/src/common/backend/utils/cache/catcache.cpp b/src/common/backend/utils/cache/catcache.cpp
index c72620d34..eb310374a 100644
--- a/src/common/backend/utils/cache/catcache.cpp
+++ b/src/common/backend/utils/cache/catcache.cpp
@@ -1575,7 +1575,7 @@ static HeapTuple SearchCatCacheMiss(
         ereport(DEBUG1, (errmsg("cache->cc_reloid - %d", cache->cc_reloid)));
 
         scandesc = systable_beginscan(
-            relation, cache->cc_indexoid, IndexScanOK(cache, cur_skey), SnapshotNow, nkeys, cur_skey);
+            relation, cache->cc_indexoid, IndexScanOK(cache, cur_skey), NULL, nkeys, cur_skey);
 
         while (HeapTupleIsValid(ntp = systable_getnext(scandesc))) {
             ct = CatalogCacheCreateEntry(cache, ntp, arguments, hashValue, hashIndex, false);
@@ -2452,7 +2452,7 @@ CatCList* SearchCatCacheList(CatCache* cache, int nkeys, Datum v1, Datum v2, Dat
         relation = heap_open(cache->cc_reloid, AccessShareLock);
 
         scandesc = systable_beginscan(
-            relation, cache->cc_indexoid, IndexScanOK(cache, cur_skey), SnapshotNow, nkeys, cur_skey);
+            relation, cache->cc_indexoid, IndexScanOK(cache, cur_skey), NULL, nkeys, cur_skey);
 
         /* The list will be ordered iff we are doing an index scan */
         ordered = (scandesc->irel != NULL);
diff --git a/src/common/backend/utils/cache/lsyscache.cpp b/src/common/backend/utils/cache/lsyscache.cpp
index 1a85e7f2d..4d243483c 100644
--- a/src/common/backend/utils/cache/lsyscache.cpp
+++ b/src/common/backend/utils/cache/lsyscache.cpp
@@ -3341,7 +3341,7 @@ static List* GetAllSliceTuples(Relation pgxcSliceRel, Oid tableOid)
         F_OIDEQ, ObjectIdGetDatum(tableOid));
     ScanKeyInit(&skey[1], Anum_pgxc_slice_type, BTEqualStrategyNumber,
         F_CHAREQ, CharGetDatum(PGXC_SLICE_TYPE_SLICE));
-    sliceScan = systable_beginscan(pgxcSliceRel, PgxcSliceOrderIndexId, true, SnapshotNow, 2, skey);
+    sliceScan = systable_beginscan(pgxcSliceRel, PgxcSliceOrderIndexId, true, NULL, 2, skey);
     while (HeapTupleIsValid((htup = systable_getnext(sliceScan)))) {
         dtup = heap_copytuple(htup);
         sliceList = lappend(sliceList, dtup);
diff --git a/src/common/backend/utils/cache/partcache.cpp b/src/common/backend/utils/cache/partcache.cpp
index c56acdd0a..aeea12d13 100644
--- a/src/common/backend/utils/cache/partcache.cpp
+++ b/src/common/backend/utils/cache/partcache.cpp
@@ -149,6 +149,10 @@ static HeapTuple ScanPgPartition(Oid targetPartId, bool indexOK, Snapshot snapsh
             (errcode(ERRCODE_UNDEFINED_DATABASE), errmsg("cannot read pg_class without having selected a database")));
     }
 
+    if (snapshot == NULL) {
+        snapshot = GetCatalogSnapshot();
+    }
+
     /*
      * form a scan key
      */
@@ -237,7 +241,7 @@ static Partition PartitionBuildDesc(Oid targetPartId, bool insertIt, bool isbukc
     /*
      * find the tuple in pg_class corresponding to the given relation id
      */
-    pg_partition_tuple = ScanPgPartition(targetPartId, true, SnapshotNow);
+    pg_partition_tuple = ScanPgPartition(targetPartId, true, NULL);
     /*
      * if no such tuple exists, return NULL
      */
@@ -378,7 +382,7 @@ Partition PartitionIdGetPartition(Oid partitionId, bool isbucket)
 
 char* PartitionOidGetName(Oid partOid)
 {
-    HeapTuple tuple = ScanPgPartition(partOid, true, SnapshotNow);
+    HeapTuple tuple = ScanPgPartition(partOid, true, NULL);
     if (!HeapTupleIsValid(tuple)) {
         return NULL;
     }
@@ -394,7 +398,7 @@ char* PartitionOidGetName(Oid partOid)
 
 Oid PartitionOidGetTablespace(Oid partOid)
 {
-    HeapTuple tuple = ScanPgPartition(partOid, true, SnapshotNow);
+    HeapTuple tuple = ScanPgPartition(partOid, true, NULL);
     if (!HeapTupleIsValid(tuple)) {
         return InvalidOid;
     }
@@ -1333,7 +1337,7 @@ static void PartitionReloadIndexInfo(Partition part)
      */
     Assert(NULL == part->pd_smgr);
 
-    pg_partition_tuple = ScanPgPartition(PartitionGetPartid(part), true, SnapshotNow);
+    pg_partition_tuple = ScanPgPartition(PartitionGetPartid(part), true, NULL);
     if (!HeapTupleIsValid(pg_partition_tuple)) {
         ereport(ERROR,
             (errcode(ERRCODE_NO_DATA),
@@ -2008,7 +2012,7 @@ bool PartitionMetadataDisabledClean(Relation pgPartition)
         &key[0], Anum_pg_partition_parttype, BTEqualStrategyNumber, F_CHAREQ, CharGetDatum(PART_OBJ_TYPE_PARTED_TABLE));
 
     partTupdesc = RelationGetDescr(pgPartition);
-    scan = systable_beginscan(pgPartition, PartitionParentOidIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(pgPartition, PartitionParentOidIndexId, true, NULL, 1, key);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         bool isNull = false;
         Datum partOptions = fastgetattr(tuple, Anum_pg_partition_reloptions, partTupdesc, &isNull);
diff --git a/src/common/backend/utils/cache/relcache.cpp b/src/common/backend/utils/cache/relcache.cpp
index b9ec32e6f..c97376f60 100644
--- a/src/common/backend/utils/cache/relcache.cpp
+++ b/src/common/backend/utils/cache/relcache.cpp
@@ -1205,11 +1205,17 @@ HeapTuple ScanPgRelation(Oid targetRelId, bool indexOK, bool force_non_historic)
     pg_class_desc = heap_open(RelationRelationId, AccessShareLock);
 
     /*
-     * for logical decoding
+     * The caller might need a tuple that's newer than the one the historic
+     * snapshot; currently the only case requiring to do so is looking up the
+     * relfilenode of non mapped system relations during decoding.
      */
     snapshot = SnapshotNow;
-    if (HistoricSnapshotActive())
-        snapshot = GetCatalogSnapshot(RelationRelationId);
+    if (HistoricSnapshotActive()) {
+        if (force_non_historic)
+            snapshot = GetNonHistoricCatalogSnapshot(RelationRelationId);
+        else
+            snapshot = GetCatalogSnapshot();
+    }
 
     /*
      * The caller might need a tuple that's newer than the one the historic
@@ -1389,6 +1395,15 @@ static void RelationBuildTupleDesc(Relation relation, bool onlyLoadInitDefVal)
         ObjectIdGetDatum(RelationGetRelid(relation)));
     ScanKeyInit(&skey[1], Anum_pg_attribute_attnum, BTGreaterStrategyNumber, F_INT2GT, Int16GetDatum(0));
 
+    /*
+     * Using historical snapshot in logic decoding.
+     */
+    Snapshot snapshot = NULL;
+    snapshot = SnapshotNow;
+    if (HistoricSnapshotActive()) {
+        snapshot =  GetCatalogSnapshot();
+    }
+
     /*
      * Open pg_attribute and begin a scan.	Force heap scan if we haven't yet
      * built the critical relcache entries (this includes initdb and startup
@@ -1396,7 +1411,7 @@ static void RelationBuildTupleDesc(Relation relation, bool onlyLoadInitDefVal)
      */
     pg_attribute_desc = heap_open(AttributeRelationId, AccessShareLock);
     pg_attribute_scan = systable_beginscan(
-        pg_attribute_desc, AttributeRelidNumIndexId, u_sess->relcache_cxt.criticalRelcachesBuilt, SnapshotNow, 2, skey);
+        pg_attribute_desc, AttributeRelidNumIndexId, u_sess->relcache_cxt.criticalRelcachesBuilt, snapshot, 2, skey);
 
     /*
      * add attribute data to relation->rd_att
@@ -1651,7 +1666,7 @@ static void RelationBuildRuleLock(Relation relation)
      */
     rewrite_desc = heap_open(RewriteRelationId, AccessShareLock);
     rewrite_tupdesc = RelationGetDescr(rewrite_desc);
-    rewrite_scan = systable_beginscan(rewrite_desc, RewriteRelRulenameIndexId, true, SnapshotNow, 1, &key);
+    rewrite_scan = systable_beginscan(rewrite_desc, RewriteRelRulenameIndexId, true, NULL, 1, &key);
 
     while (HeapTupleIsValid(rewrite_tuple = systable_getnext(rewrite_scan))) {
         Form_pg_rewrite rewrite_form = (Form_pg_rewrite)GETSTRUCT(rewrite_tuple);
@@ -2619,7 +2634,7 @@ static OpClassCacheEnt* LookupOpclassInfo(Oid operatorClassOid, StrategyNumber n
      */
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(operatorClassOid));
     rel = heap_open(OperatorClassRelationId, AccessShareLock);
-    scan = systable_beginscan(rel, OpclassOidIndexId, indexOK, SnapshotNow, 1, skey);
+    scan = systable_beginscan(rel, OpclassOidIndexId, indexOK, NULL, 1, skey);
 
     if (HeapTupleIsValid(htup = systable_getnext(scan))) {
         Form_pg_opclass opclassform = (Form_pg_opclass)GETSTRUCT(htup);
@@ -2655,7 +2670,7 @@ static OpClassCacheEnt* LookupOpclassInfo(Oid operatorClassOid, StrategyNumber n
             F_OIDEQ,
             ObjectIdGetDatum(opcentry->opcintype));
         rel = heap_open(AccessMethodProcedureRelationId, AccessShareLock);
-        scan = systable_beginscan(rel, AccessMethodProcedureIndexId, indexOK, SnapshotNow, 3, skey);
+        scan = systable_beginscan(rel, AccessMethodProcedureIndexId, indexOK, NULL, 3, skey);
 
         while (HeapTupleIsValid(htup = systable_getnext(scan))) {
             Form_pg_amproc amprocform = (Form_pg_amproc)GETSTRUCT(htup);
@@ -5022,7 +5037,7 @@ static void AttrDefaultFetch(Relation relation)
         &skey, Anum_pg_attrdef_adrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation)));
 
     adrel = heap_open(AttrDefaultRelationId, AccessShareLock);
-    adscan = systable_beginscan(adrel, AttrDefaultIndexId, true, SnapshotNow, 1, &skey);
+    adscan = systable_beginscan(adrel, AttrDefaultIndexId, true, NULL, 1, &skey);
     found = 0;
 
     while (HeapTupleIsValid(htup = systable_getnext(adscan))) {
@@ -5087,7 +5102,7 @@ static void CheckConstraintFetch(Relation relation)
         ObjectIdGetDatum(RelationGetRelid(relation)));
 
     conrel = heap_open(ConstraintRelationId, AccessShareLock);
-    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(htup = systable_getnext(conscan))) {
         Form_pg_constraint conform = (Form_pg_constraint)GETSTRUCT(htup);
@@ -5251,7 +5266,7 @@ List* RelationGetIndexList(Relation relation)
         &skey, Anum_pg_index_indrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation)));
 
     indrel = heap_open(IndexRelationId, AccessShareLock);
-    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, SnapshotNow, 1, &skey);
+    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid(htup = systable_getnext(indscan))) {
         Form_pg_index index = (Form_pg_index)GETSTRUCT(htup);
@@ -5413,7 +5428,7 @@ int RelationGetIndexNum(Relation relation)
         &skey, Anum_pg_index_indrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation)));
 
     indrel = heap_open(IndexRelationId, AccessShareLock);
-    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, SnapshotNow, 1, &skey);
+    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid(htup = systable_getnext(indscan))) {
         Form_pg_index index = (Form_pg_index)GETSTRUCT(htup);
@@ -5776,7 +5791,7 @@ static void ClusterConstraintFetch(__inout Relation relation)
         ObjectIdGetDatum(RelationGetRelid(relation)));
 
     conrel = heap_open(ConstraintRelationId, AccessShareLock);
-    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(htup = systable_getnext(conscan))) {
         Form_pg_constraint conform = (Form_pg_constraint)GETSTRUCT(htup);
@@ -6012,7 +6027,7 @@ void RelationGetExclusionInfo(Relation indexRelation, Oid** operators, Oid** pro
         ObjectIdGetDatum(indexRelation->rd_index->indrelid));
 
     conrel = heap_open(ConstraintRelationId, AccessShareLock);
-    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, skey);
     found = false;
 
     while (HeapTupleIsValid(htup = systable_getnext(conscan))) {
@@ -6936,7 +6951,7 @@ List* PartitionGetPartIndexList(Partition part)
         ObjectIdGetDatum(PartitionGetPartid(part)));
 
     partrel = heap_open(PartitionRelationId, AccessShareLock);
-    indscan = systable_beginscan(partrel, PartitionIndexTableIdIndexId, true, SnapshotNow, 1, &skey);
+    indscan = systable_beginscan(partrel, PartitionIndexTableIdIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid(parttup = systable_getnext(indscan))) {
         Form_pg_partition partform = (Form_pg_partition)GETSTRUCT(parttup);
diff --git a/src/common/backend/utils/cache/relfilenodemap.cpp b/src/common/backend/utils/cache/relfilenodemap.cpp
index fa112bd16..e1765d1f2 100644
--- a/src/common/backend/utils/cache/relfilenodemap.cpp
+++ b/src/common/backend/utils/cache/relfilenodemap.cpp
@@ -191,7 +191,10 @@ Oid RelidByRelfilenode(Oid reltablespace, Oid relfilenode)
         skey[0].sk_argument = ObjectIdGetDatum(reltablespace);
         skey[1].sk_argument = ObjectIdGetDatum(relfilenode);
 
-        scandesc = systable_beginscan(relation, ClassTblspcRelfilenodeIndexId, true, SnapshotNow, 2, skey);
+        /*
+         * Using historical snapshot in logic decoding.
+         */
+        scandesc = systable_beginscan(relation, ClassTblspcRelfilenodeIndexId, true, NULL, 2, skey);
 
         found = false;
 
@@ -270,7 +273,15 @@ Oid PartitionRelidByRelfilenode(Oid reltablespace, Oid relfilenode, Oid& partati
     skey[0].sk_argument = ObjectIdGetDatum(reltablespace);
     skey[1].sk_argument = ObjectIdGetDatum(relfilenode);
 
-    scandesc = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 2, skey);
+    /*
+     * Using historical snapshot in logic decoding.
+     */
+    Snapshot snapshot = NULL;
+    snapshot = SnapshotNow;
+    if (HistoricSnapshotActive()) {
+        snapshot =  GetCatalogSnapshot();
+    }
+    scandesc = systable_beginscan(relation, InvalidOid, false, NULL, 2, skey);
 
     while (HeapTupleIsValid(ntp = systable_getnext(scandesc))) {
         if (foundflag)
diff --git a/src/common/backend/utils/init/postinit.cpp b/src/common/backend/utils/init/postinit.cpp
index b98e986de..78fe07f28 100644
--- a/src/common/backend/utils/init/postinit.cpp
+++ b/src/common/backend/utils/init/postinit.cpp
@@ -208,7 +208,7 @@ static HeapTuple GetDatabaseTuple(const char* dbname)
      */
     relation = heap_open(DatabaseRelationId, AccessShareLock);
     scan = systable_beginscan(
-        relation, DatabaseNameIndexId, u_sess->relcache_cxt.criticalSharedRelcachesBuilt, SnapshotNow, 1, key);
+        relation, DatabaseNameIndexId, u_sess->relcache_cxt.criticalSharedRelcachesBuilt, NULL, 1, key);
 
     tuple = systable_getnext(scan);
 
@@ -245,7 +245,7 @@ static HeapTuple GetDatabaseTupleByOid(Oid dboid)
      */
     relation = heap_open(DatabaseRelationId, AccessShareLock);
     scan = systable_beginscan(
-        relation, DatabaseOidIndexId, u_sess->relcache_cxt.criticalSharedRelcachesBuilt, SnapshotNow, 1, key);
+        relation, DatabaseOidIndexId, u_sess->relcache_cxt.criticalSharedRelcachesBuilt, NULL, 1, key);
 
     tuple = systable_getnext(scan);
 
diff --git a/src/common/backend/utils/time/snapmgr.cpp b/src/common/backend/utils/time/snapmgr.cpp
index e685f4cb6..db794abc4 100644
--- a/src/common/backend/utils/time/snapmgr.cpp
+++ b/src/common/backend/utils/time/snapmgr.cpp
@@ -598,7 +598,7 @@ Snapshot GetLatestSnapshot(void)
  *      Get a snapshot that is sufficiently up-to-date for scan of the
  *      system catalog with the specified OID.
  */
-Snapshot GetCatalogSnapshot(Oid relid)
+Snapshot GetCatalogSnapshot()
 {
     /*
      * Return historic snapshot if we're doing logical decoding, but
@@ -608,7 +608,7 @@ Snapshot GetCatalogSnapshot(Oid relid)
     if (HistoricSnapshotActive())
         return u_sess->utils_cxt.HistoricSnapshot;
 
-    return GetNonHistoricCatalogSnapshot(relid);
+    return SnapshotNow;
 }
 
 /*
diff --git a/src/gausskernel/cbb/instruments/workload/instr_workload.cpp b/src/gausskernel/cbb/instruments/workload/instr_workload.cpp
index 1d52b45a0..566e5a7e4 100644
--- a/src/gausskernel/cbb/instruments/workload/instr_workload.cpp
+++ b/src/gausskernel/cbb/instruments/workload/instr_workload.cpp
@@ -263,7 +263,7 @@ static void InitInstrWorkloadTransactionUser(void)
     t_thrd.utils_cxt.CurrentResourceOwner = ResourceOwnerCreate(NULL, "ForWorkloadTransaction", MEMORY_CONTEXT_CBB);
 
     Relation relation = heap_open(AuthIdRelationId, AccessShareLock);
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
     HeapTuple tup;
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
diff --git a/src/gausskernel/cbb/workload/statctl.cpp b/src/gausskernel/cbb/workload/statctl.cpp
index 22d242bf9..deed0ec55 100644
--- a/src/gausskernel/cbb/workload/statctl.cpp
+++ b/src/gausskernel/cbb/workload/statctl.cpp
@@ -2128,7 +2128,7 @@ void WLMReAdjustAllUserSpaceInternal(bool isReset)
 
     rel = heap_open(RelationRelationId, AccessShareLock);
 
-    SysScanDesc scan = systable_beginscan(rel, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(rel, InvalidOid, false, NULL, 0, NULL);
 
     /* get all user in system table */
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
@@ -2225,7 +2225,7 @@ void WLMReAdjustUserSpaceWithResetFlagInternal(UserData* userdata, bool isReset)
 
     rel = heap_open(RelationRelationId, AccessShareLock);
 
-    SysScanDesc scan = systable_beginscan(rel, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(rel, InvalidOid, false, NULL, 0, NULL);
 
     /* get all user in system table */
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
diff --git a/src/gausskernel/cbb/workload/workload.cpp b/src/gausskernel/cbb/workload/workload.cpp
index 4a1f8a79f..5e0d0499a 100644
--- a/src/gausskernel/cbb/workload/workload.cpp
+++ b/src/gausskernel/cbb/workload/workload.cpp
@@ -199,7 +199,7 @@ void CheckRespoolMultiTenantCreate(WLMNodeGroupInfo* ng, char* cgroup, int* memp
     char* groupanme = NULL;
 
     Relation relation = heap_open(ResourcePoolRelationId, AccessShareLock);
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         Oid scanrpoid = HeapTupleGetOid(tup);
         char scancgroup[NAMEDATALEN];
@@ -385,7 +385,7 @@ void CheckRespoolMultiTenantAlter(WLMNodeGroupInfo* ng, const char* pool_name, c
 
     /* scan system table of all the resource pools */
     Relation relation = heap_open(ResourcePoolRelationId, AccessShareLock);
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
     Datum groupanme_datum;
     bool isNull = false;
     char* groupanme = NULL;
@@ -2638,7 +2638,7 @@ void DropWorkloadGroup(DropWorkloadGroupStmt* stmt)
 
     relation = heap_open(AppWorkloadGroupMappingRelationId, AccessShareLock);
 
-    scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         app_data = (Form_pg_app_workloadgroup_mapping)GETSTRUCT(tup);
@@ -3161,7 +3161,7 @@ bool BuildResourcePoolHash(LOCKMODE lockmode)
 
     TupleDesc pg_respool_dsc = RelationGetDescr(relation);
 
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         Oid rpoid = HeapTupleGetOid(tup);
@@ -3473,7 +3473,7 @@ bool BuildUserInfoHash(LOCKMODE lockmode)
 
     TupleDesc pg_authid_dsc = RelationGetDescr(relation);
 
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
 
     /* get all user in system table */
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
@@ -3799,7 +3799,7 @@ void BuildNodeGroupInfoHash(LOCKMODE lockmode)
 
     TupleDesc pg_group_dsc = RelationGetDescr(relation);
 
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
 
     /* get all user in system table */
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
@@ -3871,7 +3871,7 @@ bool GetUserChildlistFromCatalog(Oid userid, List** childlist, bool findall)
 
     TupleDesc pg_authid_dsc = RelationGetDescr(relation);
 
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         Datum authidparentidDatum = heap_getattr(tup, Anum_pg_authid_rolparentid, pg_authid_dsc, &isNULL);
diff --git a/src/gausskernel/dbmind/kernel/index_advisor.cpp b/src/gausskernel/dbmind/kernel/index_advisor.cpp
index 71ad0ae4d..19b565dbf 100644
--- a/src/gausskernel/dbmind/kernel/index_advisor.cpp
+++ b/src/gausskernel/dbmind/kernel/index_advisor.cpp
@@ -385,7 +385,7 @@ char *search_table_attname(Oid attrelid, int2 attnum)
     ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(attrelid));
     ScanKeyInit(&key[1], Anum_pg_attribute_attnum, BTEqualStrategyNumber, F_INT2EQ, Int16GetDatum(attnum));
 
-    scan = systable_beginscan(pg_attribute, AttributeRelidNumIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(pg_attribute, AttributeRelidNumIndexId, true, NULL, 2, key);
     tup = systable_getnext(scan);
     if (!HeapTupleIsValid(tup)) {
         systable_endscan(scan);
diff --git a/src/gausskernel/optimizer/commands/comment.cpp b/src/gausskernel/optimizer/commands/comment.cpp
index 7faa75c82..3e932f9bf 100644
--- a/src/gausskernel/optimizer/commands/comment.cpp
+++ b/src/gausskernel/optimizer/commands/comment.cpp
@@ -241,7 +241,7 @@ void CreateComments(Oid oid, Oid classoid, int32 subid, const char* comment)
 
     description = heap_open(DescriptionRelationId, RowExclusiveLock);
 
-    sd = systable_beginscan(description, DescriptionObjIndexId, true, SnapshotNow, 3, skey);
+    sd = systable_beginscan(description, DescriptionObjIndexId, true, NULL, 3, skey);
     if ((oldtuple = systable_getnext(sd)) != NULL) {
         /* Found the old tuple, so delete or update it */
         if (comment == NULL) {
@@ -312,7 +312,7 @@ void CreateSharedComments(Oid oid, Oid classoid, const char* comment)
 
     shdescription = heap_open(SharedDescriptionRelationId, RowExclusiveLock);
 
-    sd = systable_beginscan(shdescription, SharedDescriptionObjIndexId, true, SnapshotNow, 2, skey);
+    sd = systable_beginscan(shdescription, SharedDescriptionObjIndexId, true, NULL, 2, skey);
     if ((oldtuple = systable_getnext(sd)) != NULL) {
         /* Found the old tuple, so delete or update it */
         if (comment == NULL)
@@ -368,7 +368,7 @@ void DeleteComments(Oid oid, Oid classoid, int32 subid)
 
     description = heap_open(DescriptionRelationId, RowExclusiveLock);
 
-    sd = systable_beginscan(description, DescriptionObjIndexId, true, SnapshotNow, nkeys, skey);
+    sd = systable_beginscan(description, DescriptionObjIndexId, true, NULL, nkeys, skey);
 
     while ((oldtuple = systable_getnext(sd)) != NULL)
         simple_heap_delete(description, &oldtuple->t_self);
@@ -394,7 +394,7 @@ void DeleteSharedComments(Oid oid, Oid classoid)
 
     shdescription = heap_open(SharedDescriptionRelationId, RowExclusiveLock);
 
-    sd = systable_beginscan(shdescription, SharedDescriptionObjIndexId, true, SnapshotNow, 2, skey);
+    sd = systable_beginscan(shdescription, SharedDescriptionObjIndexId, true, NULL, 2, skey);
 
     while ((oldtuple = systable_getnext(sd)) != NULL)
         simple_heap_delete(shdescription, &oldtuple->t_self);
@@ -424,7 +424,7 @@ char* GetComment(Oid oid, Oid classoid, int32 subid)
     description = heap_open(DescriptionRelationId, AccessShareLock);
     tupdesc = RelationGetDescr(description);
 
-    sd = systable_beginscan(description, DescriptionObjIndexId, true, SnapshotNow, 3, skey);
+    sd = systable_beginscan(description, DescriptionObjIndexId, true, NULL, 3, skey);
 
     comment = NULL;
     if ((tuple = systable_getnext(sd)) != NULL) {
diff --git a/src/gausskernel/optimizer/commands/dbcommands.cpp b/src/gausskernel/optimizer/commands/dbcommands.cpp
index d35ea51e0..2c0b6fb61 100644
--- a/src/gausskernel/optimizer/commands/dbcommands.cpp
+++ b/src/gausskernel/optimizer/commands/dbcommands.cpp
@@ -1362,7 +1362,7 @@ static void movedb(const char* dbname, const char* tblspcname)
          * Update the database's pg_database tuple
          */
         ScanKeyInit(&scankey, Anum_pg_database_datname, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(dbname));
-        sysscan = systable_beginscan(pgdbrel, DatabaseNameIndexId, true, SnapshotNow, 1, &scankey);
+        sysscan = systable_beginscan(pgdbrel, DatabaseNameIndexId, true, NULL, 1, &scankey);
         oldtuple = systable_getnext(sysscan);
         if (!HeapTupleIsValid(oldtuple)) /* shouldn't happen... */
             ereport(ERROR, (errcode(ERRCODE_UNDEFINED_DATABASE), errmsg("database \"%s\" does not exist", dbname)));
@@ -1597,7 +1597,7 @@ void AlterDatabase(AlterDatabaseStmt* stmt, bool isTopLevel)
      */
     rel = heap_open(DatabaseRelationId, RowExclusiveLock);
     ScanKeyInit(&scankey, Anum_pg_database_datname, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(stmt->dbname));
-    scan = systable_beginscan(rel, DatabaseNameIndexId, true, SnapshotNow, 1, &scankey);
+    scan = systable_beginscan(rel, DatabaseNameIndexId, true, NULL, 1, &scankey);
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
         ereport(ERROR, (errcode(ERRCODE_UNDEFINED_DATABASE), errmsg("database \"%s\" does not exist", stmt->dbname)));
@@ -1688,7 +1688,7 @@ void AlterDatabaseOwner(const char* dbname, Oid newOwnerId)
      */
     rel = heap_open(DatabaseRelationId, RowExclusiveLock);
     ScanKeyInit(&scankey, Anum_pg_database_datname, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(dbname));
-    scan = systable_beginscan(rel, DatabaseNameIndexId, true, SnapshotNow, 1, &scankey);
+    scan = systable_beginscan(rel, DatabaseNameIndexId, true, NULL, 1, &scankey);
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
         ereport(ERROR, (errcode(ERRCODE_UNDEFINED_DATABASE), errmsg("database \"%s\" does not exist", dbname)));
@@ -1803,7 +1803,7 @@ static bool get_db_info(const char* name, LOCKMODE lockmode, Oid* dbIdP, Oid* ow
          */
         ScanKeyInit(&scanKey, Anum_pg_database_datname, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(name));
 
-        scan = systable_beginscan(relation, DatabaseNameIndexId, true, SnapshotNow, 1, &scanKey);
+        scan = systable_beginscan(relation, DatabaseNameIndexId, true, NULL, 1, &scanKey);
 
         tuple = systable_getnext(scan);
 
@@ -2084,7 +2084,7 @@ Oid get_database_oid(const char* dbname, bool missing_ok)
      */
     pg_database = heap_open(DatabaseRelationId, AccessShareLock);
     ScanKeyInit(&entry[0], Anum_pg_database_datname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(dbname));
-    scan = systable_beginscan(pg_database, DatabaseNameIndexId, true, SnapshotNow, 1, entry);
+    scan = systable_beginscan(pg_database, DatabaseNameIndexId, true, NULL, 1, entry);
 
     dbtuple = systable_getnext(scan);
 
diff --git a/src/gausskernel/optimizer/commands/directory.cpp b/src/gausskernel/optimizer/commands/directory.cpp
index 3e81dd3f7..e21012a56 100644
--- a/src/gausskernel/optimizer/commands/directory.cpp
+++ b/src/gausskernel/optimizer/commands/directory.cpp
@@ -362,7 +362,7 @@ void AlterDirectoryOwner(const char* dirname, Oid newOwnerId)
      */
     rel = heap_open(PgDirectoryRelationId, RowExclusiveLock);
     ScanKeyInit(&scankey, Anum_pg_directory_directory_name, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(dirname));
-    scan = systable_beginscan(rel, PgDirectoryDirectoriesNameIndexId, true, SnapshotNow, 1, &scankey);
+    scan = systable_beginscan(rel, PgDirectoryDirectoriesNameIndexId, true, NULL, 1, &scankey);
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple)) {
         heap_close(rel, RowExclusiveLock);
diff --git a/src/gausskernel/optimizer/commands/extension.cpp b/src/gausskernel/optimizer/commands/extension.cpp
index 84ec58a92..2b3464573 100644
--- a/src/gausskernel/optimizer/commands/extension.cpp
+++ b/src/gausskernel/optimizer/commands/extension.cpp
@@ -116,7 +116,7 @@ Oid get_extension_oid(const char* extname, bool missing_ok)
 
     ScanKeyInit(&entry[0], Anum_pg_extension_extname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(extname));
 
-    scandesc = systable_beginscan(rel, ExtensionNameIndexId, true, SnapshotNow, 1, entry);
+    scandesc = systable_beginscan(rel, ExtensionNameIndexId, true, NULL, 1, entry);
 
     tuple = systable_getnext(scandesc);
 
@@ -153,7 +153,7 @@ char* get_extension_name(Oid ext_oid)
 
     ScanKeyInit(&entry[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ext_oid));
 
-    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, SnapshotNow, 1, entry);
+    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, NULL, 1, entry);
 
     tuple = systable_getnext(scandesc);
 
@@ -187,7 +187,7 @@ static Oid get_extension_schema(Oid ext_oid)
 
     ScanKeyInit(&entry[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ext_oid));
 
-    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, SnapshotNow, 1, entry);
+    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, NULL, 1, entry);
 
     tuple = systable_getnext(scandesc);
 
@@ -1564,7 +1564,7 @@ void RemoveExtensionById(Oid extId)
     rel = heap_open(ExtensionRelationId, RowExclusiveLock);
 
     ScanKeyInit(&entry[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(extId));
-    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, SnapshotNow, 1, entry);
+    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, NULL, 1, entry);
 
     tuple = systable_getnext(scandesc);
 
@@ -2045,7 +2045,7 @@ Datum pg_extension_config_dump(PG_FUNCTION_ARGS)
         F_OIDEQ,
         ObjectIdGetDatum(u_sess->cmd_cxt.CurrentExtensionObject));
 
-    extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, SnapshotNow, 1, key);
+    extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, NULL, 1, key);
 
     extTup = systable_getnext(extScan);
 
@@ -2176,7 +2176,7 @@ static void extension_config_remove(Oid extensionoid, Oid tableoid)
 
     ScanKeyInit(&key[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(extensionoid));
 
-    extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, SnapshotNow, 1, key);
+    extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, NULL, 1, key);
 
     extTup = systable_getnext(extScan);
 
@@ -2351,7 +2351,7 @@ void AlterExtensionNamespace(List* names, const char* newschema)
 
     ScanKeyInit(&key[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(extensionOid));
 
-    extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, SnapshotNow, 1, key);
+    extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, NULL, 1, key);
 
     extTup = systable_getnext(extScan);
 
@@ -2392,7 +2392,7 @@ void AlterExtensionNamespace(List* names, const char* newschema)
         &key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ExtensionRelationId));
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(extensionOid));
 
-    depScan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    depScan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(depTup = systable_getnext(depScan))) {
         Form_pg_depend pg_depend = (Form_pg_depend)GETSTRUCT(depTup);
@@ -2486,7 +2486,7 @@ void ExecAlterExtensionStmt(AlterExtensionStmt* stmt)
 
     ScanKeyInit(&key[0], Anum_pg_extension_extname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(stmt->extname));
 
-    extScan = systable_beginscan(extRel, ExtensionNameIndexId, true, SnapshotNow, 1, key);
+    extScan = systable_beginscan(extRel, ExtensionNameIndexId, true, NULL, 1, key);
 
     extTup = systable_getnext(extScan);
 
@@ -2610,7 +2610,7 @@ static void ApplyExtensionUpdates(
 
         ScanKeyInit(&key[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(extensionOid));
 
-        extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, SnapshotNow, 1, key);
+        extScan = systable_beginscan(extRel, ExtensionOidIndexId, true, NULL, 1, key);
 
         extTup = systable_getnext(extScan);
 
@@ -2830,7 +2830,7 @@ static void AlterExtensionOwner_internal(Relation rel, Oid extensionOid, Oid new
 
     ScanKeyInit(&entry[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(extensionOid));
 
-    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, SnapshotNow, 1, entry);
+    scandesc = systable_beginscan(rel, ExtensionOidIndexId, true, NULL, 1, entry);
 
     /* We assume that there can be at most one matching tuple */
     tup = systable_getnext(scandesc);
diff --git a/src/gausskernel/optimizer/commands/functioncmds.cpp b/src/gausskernel/optimizer/commands/functioncmds.cpp
index f19c2ba60..6cb61b29e 100644
--- a/src/gausskernel/optimizer/commands/functioncmds.cpp
+++ b/src/gausskernel/optimizer/commands/functioncmds.cpp
@@ -2114,7 +2114,7 @@ void DropCastById(Oid castOid)
     relation = heap_open(CastRelationId, RowExclusiveLock);
 
     ScanKeyInit(&scankey, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(castOid));
-    scan = systable_beginscan(relation, CastOidIndexId, true, SnapshotNow, 1, &scankey);
+    scan = systable_beginscan(relation, CastOidIndexId, true, NULL, 1, &scankey);
 
     tuple = systable_getnext(scan);
     if (!HeapTupleIsValid(tuple))
diff --git a/src/gausskernel/optimizer/commands/indexcmds.cpp b/src/gausskernel/optimizer/commands/indexcmds.cpp
index e9919d894..7cc727eaa 100644
--- a/src/gausskernel/optimizer/commands/indexcmds.cpp
+++ b/src/gausskernel/optimizer/commands/indexcmds.cpp
@@ -1921,7 +1921,7 @@ Oid GetDefaultOpClass(Oid type_id, Oid am_id)
 
     ScanKeyInit(&skey[0], Anum_pg_opclass_opcmethod, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(am_id));
 
-    scan = systable_beginscan(rel, OpclassAmNameNspIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(rel, OpclassAmNameNspIndexId, true, NULL, 1, skey);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_opclass opclass = (Form_pg_opclass)GETSTRUCT(tup);
@@ -2937,7 +2937,7 @@ static bool relationHasInformationalPrimaryKey(const Relation rel)
     ScanKeyInit(
         &skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
     conrel = heap_open(ConstraintRelationId, ShareUpdateExclusiveLock);
-    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, skey);
     while (HeapTupleIsValid(htup = systable_getnext(conscan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(htup);
 
@@ -3118,7 +3118,7 @@ static bool CheckGlobalIndexCompatible(Oid relOid, bool isGlobal, const IndexInf
 
     ScanKeyInit(&skey[0], Anum_pg_index_indrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relOid));
     indexRelation = heap_open(IndexRelationId, AccessShareLock);
-    sysScan = systable_beginscan(indexRelation, IndexIndrelidIndexId, true, SnapshotNow, 1, skey);
+    sysScan = systable_beginscan(indexRelation, IndexIndrelidIndexId, true, NULL, 1, skey);
 
     AttrNumber* currAttrsArray = (AttrNumber*)palloc0(currSize);
     rc = memcpy_s(currAttrsArray, currSize, indexInfo->ii_KeyAttrNumbers, currSize);
diff --git a/src/gausskernel/optimizer/commands/matview.cpp b/src/gausskernel/optimizer/commands/matview.cpp
index 55fa79aa8..bb8143c93 100644
--- a/src/gausskernel/optimizer/commands/matview.cpp
+++ b/src/gausskernel/optimizer/commands/matview.cpp
@@ -506,7 +506,7 @@ static void ExecutorMatMapDelete(Oid mapid, Oid relid, ItemPointer rel_ctid, Oid
     }
     Oid indexOid = (Oid)linitial_oid(indexOidList);
 
-    scan = systable_beginscan(mapRel, indexOid, true, SnapshotNow, 3, scankey);
+    scan = systable_beginscan(mapRel, indexOid, true, NULL, 3, scankey);
     if (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         Datum matctid = heap_getattr(tuple,
                                      MatMapAttributeMatctid,
@@ -1981,7 +1981,7 @@ Oid find_matview_mlog_table(Oid relid)
 
     ScanKeyInit(&scanKey, Anum_pg_class_relname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(mlogname));
     rel = heap_open(RelationRelationId, AccessShareLock);
-    scan = systable_beginscan(rel, ClassNameNspIndexId, true, SnapshotNow, 1, &scanKey);
+    scan = systable_beginscan(rel, ClassNameNspIndexId, true, NULL, 1, &scanKey);
     tup = systable_getnext(scan);
 
     if (HeapTupleIsValid(tup)) {
@@ -2472,7 +2472,7 @@ static List* get_distkey_info(Oid oid) {
 
     ScanKeyInit(&scanKey, Anum_pgxc_class_pcrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(oid));
     rel = heap_open(PgxcClassRelationId, AccessShareLock);
-    scan = systable_beginscan(rel, PgxcClassPgxcRelIdIndexId, true, SnapshotNow, 1, &scanKey);
+    scan = systable_beginscan(rel, PgxcClassPgxcRelIdIndexId, true, NULL, 1, &scanKey);
     tup = systable_getnext(scan);
 
     Assert(HeapTupleIsValid(tup));
diff --git a/src/gausskernel/optimizer/commands/opclasscmds.cpp b/src/gausskernel/optimizer/commands/opclasscmds.cpp
index 14113dbf2..736183742 100644
--- a/src/gausskernel/optimizer/commands/opclasscmds.cpp
+++ b/src/gausskernel/optimizer/commands/opclasscmds.cpp
@@ -547,7 +547,7 @@ void DefineOpClass(CreateOpClassStmt* stmt)
 
         ScanKeyInit(&skey[0], Anum_pg_opclass_opcmethod, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(amoid));
 
-        scan = systable_beginscan(rel, OpclassAmNameNspIndexId, true, SnapshotNow, 1, skey);
+        scan = systable_beginscan(rel, OpclassAmNameNspIndexId, true, NULL, 1, skey);
 
         while (HeapTupleIsValid(tup = systable_getnext(scan))) {
             Form_pg_opclass opclass = (Form_pg_opclass)GETSTRUCT(tup);
@@ -1453,7 +1453,7 @@ void RemoveAmOpEntryById(Oid entryOid)
 
     rel = heap_open(AccessMethodOperatorRelationId, RowExclusiveLock);
 
-    scan = systable_beginscan(rel, AccessMethodOperatorOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(rel, AccessMethodOperatorOidIndexId, true, NULL, 1, skey);
 
     /* we expect exactly one match */
     tup = systable_getnext(scan);
@@ -1477,7 +1477,7 @@ void RemoveAmProcEntryById(Oid entryOid)
 
     rel = heap_open(AccessMethodProcedureRelationId, RowExclusiveLock);
 
-    scan = systable_beginscan(rel, AccessMethodProcedureOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(rel, AccessMethodProcedureOidIndexId, true, NULL, 1, skey);
 
     /* we expect exactly one match */
     tup = systable_getnext(scan);
diff --git a/src/gausskernel/optimizer/commands/proclang.cpp b/src/gausskernel/optimizer/commands/proclang.cpp
index 3c7b76bd5..4f9b8ec80 100644
--- a/src/gausskernel/optimizer/commands/proclang.cpp
+++ b/src/gausskernel/optimizer/commands/proclang.cpp
@@ -440,7 +440,7 @@ static PLTemplate* find_language_template(const char* languageName)
     rel = heap_open(PLTemplateRelationId, AccessShareLock);
 
     ScanKeyInit(&key, Anum_pg_pltemplate_tmplname, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(languageName));
-    scan = systable_beginscan(rel, PLTemplateNameIndexId, true, SnapshotNow, 1, &key);
+    scan = systable_beginscan(rel, PLTemplateNameIndexId, true, NULL, 1, &key);
 
     tup = systable_getnext(scan);
     if (HeapTupleIsValid(tup)) {
diff --git a/src/gausskernel/optimizer/commands/sec_rls_cmds.cpp b/src/gausskernel/optimizer/commands/sec_rls_cmds.cpp
index 2755cae53..ff7c78722 100644
--- a/src/gausskernel/optimizer/commands/sec_rls_cmds.cpp
+++ b/src/gausskernel/optimizer/commands/sec_rls_cmds.cpp
@@ -173,7 +173,7 @@ void CreateRlsPolicy(CreateRlsPolicyStmt* stmt)
 
     /* Search old tuple by index */
     SysScanDesc scanDesc =
-        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 2, scanKey);
+        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 2, scanKey);
     HeapTuple rlsPolicyTuple = systable_getnext(scanDesc);
 
     /* Policy already exists */
@@ -188,7 +188,7 @@ void CreateRlsPolicy(CreateRlsPolicyStmt* stmt)
 
     /* RLS policies for one relation should not large than MaxRlsPolciesForRelation */
     ScanKeyInit(&scanKey[0], Anum_pg_rlspolicy_polrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(tableOid));
-    scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 1, scanKey);
+    scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 1, scanKey);
     int existRlsNum = 0;
     while ((rlsPolicyTuple = systable_getnext(scanDesc)) != NULL) {
         existRlsNum++;
@@ -310,7 +310,7 @@ void AlterRlsPolicy(AlterRlsPolicyStmt* stmt)
 
     /* Search tuple by index */
     SysScanDesc scanDesc =
-        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 2, scanKey);
+        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 2, scanKey);
     HeapTuple rlsPolicyTuple = systable_getnext(scanDesc);
 
     /* Policy does not exists */
@@ -498,7 +498,7 @@ void RenameRlsPolicy(RenameStmt* renameStmt)
 
     /* Search tuple by index */
     SysScanDesc scanDesc =
-        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 2, scanKey);
+        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 2, scanKey);
     HeapTuple rlsPolicyTuple = systable_getnext(scanDesc);
 
     /* Policy already exists */
@@ -516,7 +516,7 @@ void RenameRlsPolicy(RenameStmt* renameStmt)
     ScanKeyInit(&scanKey[0], Anum_pg_rlspolicy_polrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
     ScanKeyInit(
         &scanKey[1], Anum_pg_rlspolicy_polname, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(renameStmt->subname));
-    scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 2, scanKey);
+    scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 2, scanKey);
     rlsPolicyTuple = systable_getnext(scanDesc);
     /* Policy does not exists */
     if (HeapTupleIsValid(rlsPolicyTuple) == false) {
@@ -572,7 +572,7 @@ bool RemoveRoleFromRlsPolicy(Oid roleid, Oid rlsrelid, Oid rlspolicyid)
     ScanKeyData scanKey[1];
     ScanKeyInit(&scanKey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, rlspolicyid);
     /* search tuple by index */
-    SysScanDesc scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyOidIndex, true, SnapshotNow, 1, scanKey);
+    SysScanDesc scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyOidIndex, true, NULL, 1, scanKey);
     HeapTuple rlsPolicyTuple = systable_getnext(scanDesc);
     if (false == HeapTupleIsValid(rlsPolicyTuple)) {
         ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("could not find tuple for policy %u", rlspolicyid)));
@@ -686,7 +686,7 @@ void RemoveRlsPolicyById(Oid rlsPolicyOid)
     Relation pg_rlspolicy = heap_open(RlsPolicyRelationId, RowExclusiveLock);
 
     /* Search tuple by index */
-    SysScanDesc scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyOidIndex, true, SnapshotNow, 1, scanKey);
+    SysScanDesc scanDesc = systable_beginscan(pg_rlspolicy, PgRlspolicyOidIndex, true, NULL, 1, scanKey);
 
     HeapTuple tuple = systable_getnext(scanDesc);
     if (!HeapTupleIsValid(tuple)) {
@@ -739,7 +739,7 @@ Oid get_rlspolicy_oid(Oid relid, const char* policy_name, bool missing_ok)
 
     /* Search old tuple by index */
     SysScanDesc scanDesc =
-        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 2, scanKey);
+        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 2, scanKey);
     HeapTuple rlsPolicyTuple = systable_getnext(scanDesc);
 
     if (HeapTupleIsValid(rlsPolicyTuple)) {
@@ -783,7 +783,7 @@ void RelationBuildRlsPolicies(Relation relation)
 
     /* Search old tuple by index */
     SysScanDesc scanDesc =
-        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 1, scanKey);
+        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 1, scanKey);
 
     MemoryContext oldcxt = NULL;
     /*
@@ -1042,7 +1042,7 @@ bool RelationHasRlspolicy(Oid relid)
 
     /* Search tuple by index */
     SysScanDesc scanDesc =
-        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, SnapshotNow, 1, scanKey);
+        systable_beginscan(pg_rlspolicy, PgRlspolicyPolrelidPolnameIndex, true, NULL, 1, scanKey);
     HeapTuple rlsPolicyTuple = systable_getnext(scanDesc);
     /* Find RLS policy for this relation */
     int findPolicy = false;
diff --git a/src/gausskernel/optimizer/commands/seclabel.cpp b/src/gausskernel/optimizer/commands/seclabel.cpp
index 16129b197..5508e470c 100644
--- a/src/gausskernel/optimizer/commands/seclabel.cpp
+++ b/src/gausskernel/optimizer/commands/seclabel.cpp
@@ -151,7 +151,7 @@ static char* GetSharedSecurityLabel(const ObjectAddress* object, const char* pro
 
     pg_shseclabel = heap_open(SharedSecLabelRelationId, AccessShareLock);
 
-    scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true, SnapshotNow, 3, keys);
+    scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true, NULL, 3, keys);
 
     tuple = systable_getnext(scan);
     if (HeapTupleIsValid(tuple)) {
@@ -193,7 +193,7 @@ char* GetSecurityLabel(const ObjectAddress* object, const char* provider)
 
     pg_seclabel = heap_open(SecLabelRelationId, AccessShareLock);
 
-    scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true, SnapshotNow, 4, keys);
+    scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true, NULL, 4, keys);
 
     tuple = systable_getnext(scan);
     if (HeapTupleIsValid(tuple)) {
@@ -243,7 +243,7 @@ static void SetSharedSecurityLabel(const ObjectAddress* object, const char* prov
 
     pg_shseclabel = heap_open(SharedSecLabelRelationId, RowExclusiveLock);
 
-    scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true, SnapshotNow, 3, keys);
+    scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true, NULL, 3, keys);
 
     oldtup = systable_getnext(scan);
     if (HeapTupleIsValid(oldtup)) {
@@ -312,7 +312,7 @@ void SetSecurityLabel(const ObjectAddress* object, const char* provider, const c
 
     Relation pg_seclabel = heap_open(SecLabelRelationId, RowExclusiveLock);
 
-    SysScanDesc scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true, SnapshotNow, 4, keys);
+    SysScanDesc scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true, NULL, 4, keys);
 
     HeapTuple oldtup = systable_getnext(scan);
     if (HeapTupleIsValid(oldtup)) {
@@ -357,7 +357,7 @@ void DeleteSharedSecurityLabel(Oid objectId, Oid classId)
 
     pg_shseclabel = heap_open(SharedSecLabelRelationId, RowExclusiveLock);
 
-    scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true, SnapshotNow, 2, skey);
+    scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true, NULL, 2, skey);
     while (HeapTupleIsValid(oldtup = systable_getnext(scan)))
         simple_heap_delete(pg_shseclabel, &oldtup->t_self);
     systable_endscan(scan);
@@ -395,7 +395,7 @@ void DeleteSecurityLabel(const ObjectAddress* object)
 
     pg_seclabel = heap_open(SecLabelRelationId, RowExclusiveLock);
 
-    scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true, SnapshotNow, nkeys, skey);
+    scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true, NULL, nkeys, skey);
     while (HeapTupleIsValid(oldtup = systable_getnext(scan)))
         simple_heap_delete(pg_seclabel, &oldtup->t_self);
     systable_endscan(scan);
diff --git a/src/gausskernel/optimizer/commands/tablecmds.cpp b/src/gausskernel/optimizer/commands/tablecmds.cpp
index 0ea81d90f..b888c4cfb 100644
--- a/src/gausskernel/optimizer/commands/tablecmds.cpp
+++ b/src/gausskernel/optimizer/commands/tablecmds.cpp
@@ -8152,7 +8152,7 @@ void find_composite_type_dependencies(Oid typeOid, Relation origRelation, const
     ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(TypeRelationId));
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(typeOid));
 
-    depScan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    depScan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(depTup = systable_getnext(depScan))) {
         Form_pg_depend pg_depend = (Form_pg_depend)GETSTRUCT(depTup);
@@ -10554,7 +10554,7 @@ static void ATExecValidateConstraint(Relation rel, char* constrName, bool recurs
      */
     ScanKeyInit(
         &key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
-    scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, &key);
+    scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, &key);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -11349,7 +11349,7 @@ static void ATExecDropConstraint(Relation rel, const char* constrName, DropBehav
      */
     ScanKeyInit(
         &key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
-    scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, &key);
+    scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, &key);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         ObjectAddress conobj;
@@ -11458,7 +11458,7 @@ static void ATExecDropConstraint(Relation rel, const char* constrName, DropBehav
         CheckTableNotInUse(childrel, "ALTER TABLE");
 
         ScanKeyInit(&key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(childrelid));
-        scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, &key);
+        scan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, &key);
 
         /* scan for matching tuple - there should only be one */
         while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
@@ -11882,7 +11882,7 @@ static void ATExecAlterColumnType(AlteredTableInfo* tab, Relation rel, AlterTabl
         &key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
     ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum((int32)attnum));
 
-    scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 3, key);
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 3, key);
 
     while (HeapTupleIsValid(depTup = systable_getnext(scan))) {
         Form_pg_depend foundDep = (Form_pg_depend)GETSTRUCT(depTup);
@@ -13051,7 +13051,7 @@ static void change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid ne
 
     attRelation = heap_open(AttributeRelationId, RowExclusiveLock);
     ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationOid));
-    scan = systable_beginscan(attRelation, AttributeRelidNumIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(attRelation, AttributeRelidNumIndexId, true, NULL, 1, key);
     while (HeapTupleIsValid(attributeTuple = systable_getnext(scan))) {
         Form_pg_attribute att = (Form_pg_attribute)GETSTRUCT(attributeTuple);
         Datum repl_val[Natts_pg_attribute];
@@ -13116,7 +13116,7 @@ static void change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, L
         &key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId));
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationOid));
     /* we leave refobjsubid unspecified */
-    scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend depForm = (Form_pg_depend)GETSTRUCT(tup);
@@ -14529,7 +14529,7 @@ static void ATExecAddInherit(Relation child_rel, RangeVar* parent, LOCKMODE lock
     catalogRelation = heap_open(InheritsRelationId, RowExclusiveLock);
     ScanKeyInit(
         &key, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel)));
-    scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, SnapshotNow, 1, &key);
+    scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, &key);
 
     /* inhseqno sequences start at 1 */
     inhseqno = 0;
@@ -14750,7 +14750,7 @@ static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel
         BTEqualStrategyNumber,
         F_OIDEQ,
         ObjectIdGetDatum(RelationGetRelid(parent_rel)));
-    parent_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId, true, SnapshotNow, 1, &parent_key);
+    parent_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId, true, NULL, 1, &parent_key);
 
     while (HeapTupleIsValid(parent_tuple = systable_getnext(parent_scan))) {
         Form_pg_constraint parent_con = (Form_pg_constraint)GETSTRUCT(parent_tuple);
@@ -14772,7 +14772,7 @@ static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel
             BTEqualStrategyNumber,
             F_OIDEQ,
             ObjectIdGetDatum(RelationGetRelid(child_rel)));
-        child_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId, true, SnapshotNow, 1, &child_key);
+        child_scan = systable_beginscan(catalog_relation, ConstraintRelidIndexId, true, NULL, 1, &child_key);
 
         while (HeapTupleIsValid(child_tuple = systable_getnext(child_scan))) {
             Form_pg_constraint child_con = (Form_pg_constraint)GETSTRUCT(child_tuple);
@@ -14870,7 +14870,7 @@ static void ATExecDropInherit(Relation rel, RangeVar* parent, LOCKMODE lockmode)
     catalogRelation = heap_open(InheritsRelationId, RowExclusiveLock);
     ScanKeyInit(
         &key[0], Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
-    scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, key);
 
     while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan))) {
         Oid inhparent;
@@ -14899,7 +14899,7 @@ static void ATExecDropInherit(Relation rel, RangeVar* parent, LOCKMODE lockmode)
     catalogRelation = heap_open(AttributeRelationId, RowExclusiveLock);
     ScanKeyInit(
         &key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
-    scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId, true, NULL, 1, key);
     while (HeapTupleIsValid(attributeTuple = systable_getnext(scan))) {
         Form_pg_attribute att = (Form_pg_attribute)GETSTRUCT(attributeTuple);
 
@@ -14938,7 +14938,7 @@ static void ATExecDropInherit(Relation rel, RangeVar* parent, LOCKMODE lockmode)
         BTEqualStrategyNumber,
         F_OIDEQ,
         ObjectIdGetDatum(RelationGetRelid(parent_rel)));
-    scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId, true, NULL, 1, key);
 
     connames = NIL;
 
@@ -14954,7 +14954,7 @@ static void ATExecDropInherit(Relation rel, RangeVar* parent, LOCKMODE lockmode)
     /* Now scan the child's constraints */
     ScanKeyInit(
         &key[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
-    scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId, true, SnapshotNow, 1, key);
+    scan = systable_beginscan(catalogRelation, ConstraintRelidIndexId, true, NULL, 1, key);
 
     while (HeapTupleIsValid(constraintTuple = systable_getnext(scan))) {
         Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(constraintTuple);
@@ -15023,7 +15023,7 @@ static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid)
     ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
     ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(0));
 
-    scan = systable_beginscan(catalogRelation, DependDependerIndexId, true, SnapshotNow, 3, key);
+    scan = systable_beginscan(catalogRelation, DependDependerIndexId, true, NULL, 3, key);
 
     while (HeapTupleIsValid(depTuple = systable_getnext(scan))) {
         Form_pg_depend dep = (Form_pg_depend)GETSTRUCT(depTuple);
@@ -15073,7 +15073,7 @@ static void ATExecAddOf(Relation rel, const TypeName* ofTypename, LOCKMODE lockm
     /* Fail if the table has any inheritance parents. */
     inheritsRelation = heap_open(InheritsRelationId, AccessShareLock);
     ScanKeyInit(&key, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
-    scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId, true, SnapshotNow, 1, &key);
+    scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, &key);
     if (HeapTupleIsValid(systable_getnext(scan)))
         ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("typed tables cannot inherit")));
     systable_endscan(scan);
@@ -16384,7 +16384,7 @@ static void AlterSeqNamespaces(
     ScanKeyInit(
         &key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
     /* we leave refobjsubid unspecified */
-    scan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         Form_pg_depend depForm = (Form_pg_depend)GETSTRUCT(tup);
@@ -19909,7 +19909,7 @@ static void checkColumnForExchange(Relation partTableRel, Relation ordTableRel)
         ScanKeyInit(&scankeys[1], Anum_pg_attrdef_adnum, BTEqualStrategyNumber, F_INT2EQ,
             partVals[Anum_pg_attribute_attnum - 1]);
 
-        partAttrdefScan = systable_beginscan(attrdefRel, AttrDefaultIndexId, true, SnapshotNow, 2, scankeys);
+        partAttrdefScan = systable_beginscan(attrdefRel, AttrDefaultIndexId, true, NULL, 2, scankeys);
         partAttrdefTuple = systable_getnext(partAttrdefScan);
 
         ScanKeyInit(&scankeys[0],
@@ -19920,7 +19920,7 @@ static void checkColumnForExchange(Relation partTableRel, Relation ordTableRel)
         ScanKeyInit(&scankeys[1], Anum_pg_attrdef_adnum, BTEqualStrategyNumber, F_INT2EQ,
             ordVals[Anum_pg_attribute_attnum - 1]);
 
-        ordAttrdefScan = systable_beginscan(attrdefRel, AttrDefaultIndexId, true, SnapshotNow, 2, scankeys);
+        ordAttrdefScan = systable_beginscan(attrdefRel, AttrDefaultIndexId, true, NULL, 2, scankeys);
         ordAttrdefTuple = systable_getnext(ordAttrdefScan);
 
         if ((partAttrdefTuple != NULL) && (ordAttrdefTuple != NULL)) {
@@ -19997,7 +19997,7 @@ bool checkPartitionLocalIndexesUsable(Oid partitionOid)
     pg_part_rel = relation_open(PartitionRelationId, AccessShareLock);
     ScanKeyInit(
         &scankeys[0], Anum_pg_partition_indextblid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(partitionOid));
-    partScan = systable_beginscan(pg_part_rel, PartitionIndexTableIdIndexId, true, SnapshotNow, 1, scankeys);
+    partScan = systable_beginscan(pg_part_rel, PartitionIndexTableIdIndexId, true, NULL, 1, scankeys);
     while (NULL != (partTuple = systable_getnext(partScan))) {
         Relation indexRel = NULL;
         Partition indexPart = NULL;
@@ -20044,7 +20044,7 @@ bool checkRelationLocalIndexesUsable(Relation relation)
         &skey, Anum_pg_index_indrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation)));
 
     indrel = heap_open(IndexRelationId, AccessShareLock);
-    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, SnapshotNow, 1, &skey);
+    indscan = systable_beginscan(indrel, IndexIndrelidIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid(htup = systable_getnext(indscan))) {
         Form_pg_index index = (Form_pg_index)GETSTRUCT(htup);
@@ -20222,11 +20222,11 @@ static List* getConstraintList(Oid relOid, char conType)
     if (conType != CONSTRAINT_INVALID) {
         ScanKeyInit(&skey[1], Anum_pg_constraint_contype, BTEqualStrategyNumber, F_CHAREQ, CharGetDatum(conType));
         nkeys = 2;
-        scan = systable_beginscan(pgConstraint, ConstraintRelidIndexId, false, SnapshotNow, nkeys, skey);
+        scan = systable_beginscan(pgConstraint, ConstraintRelidIndexId, false, NULL, nkeys, skey);
 
     } else {
         nkeys = 1;
-        scan = systable_beginscan(pgConstraint, ConstraintRelidIndexId, true, SnapshotNow, nkeys, skey);
+        scan = systable_beginscan(pgConstraint, ConstraintRelidIndexId, true, NULL, nkeys, skey);
     }
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
@@ -23323,7 +23323,7 @@ static void ResetPartsRedisCtidRelOptions(Relation rel)
     ScanKeyInit(&key[1], Anum_pg_partition_parentid, BTEqualStrategyNumber,F_OIDEQ, 
         ObjectIdGetDatum(RelationGetRelid(rel)));
 
-    scan = systable_beginscan(pg_partition, PartitionParentOidIndexId, true, SnapshotNow, 2, key);
+    scan = systable_beginscan(pg_partition, PartitionParentOidIndexId, true, NULL, 2, key);
     redis_reloptions = AlterTableSetRedistribute(rel, REDIS_REL_RESET_CTID, NULL);
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         HeapTuple dtuple;
diff --git a/src/gausskernel/optimizer/commands/trigger.cpp b/src/gausskernel/optimizer/commands/trigger.cpp
index 736db0c1d..c7dddfd35 100644
--- a/src/gausskernel/optimizer/commands/trigger.cpp
+++ b/src/gausskernel/optimizer/commands/trigger.cpp
@@ -516,7 +516,7 @@ Oid CreateTrigger(CreateTrigStmt* stmt, const char* queryString, Oid relOid, Oid
     if (!isInternal) {
         ScanKeyInit(
             &key, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel)));
-        tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, SnapshotNow, 1, &key);
+        tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 1, &key);
         while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) {
             Form_pg_trigger pg_trigger = (Form_pg_trigger)GETSTRUCT(tuple);
             if (namestrcmp(&(pg_trigger->tgname), trigname) == 0)
@@ -1033,7 +1033,7 @@ void RemoveTriggerById(Oid trigOid)
      */
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(trigOid));
 
-    tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true, SnapshotNow, 1, skey);
+    tgscan = systable_beginscan(tgrel, TriggerOidIndexId, true, NULL, 1, skey);
 
     tup = systable_getnext(tgscan);
     if (!HeapTupleIsValid(tup))
@@ -1103,7 +1103,7 @@ Oid get_trigger_oid(Oid relid, const char* trigname, bool missing_ok)
     ScanKeyInit(&skey[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
     ScanKeyInit(&skey[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(trigname));
 
-    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, SnapshotNow, 2, skey);
+    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 2, skey);
 
     tup = systable_getnext(tgscan);
     if (!HeapTupleIsValid(tup)) {
@@ -1199,7 +1199,7 @@ void renametrig(RenameStmt* stmt)
      */
     ScanKeyInit(&key[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
     ScanKeyInit(&key[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, PointerGetDatum(stmt->newname));
-    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, SnapshotNow, 2, key);
+    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 2, key);
     if (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
         ereport(ERROR,
             (errcode(ERRCODE_DUPLICATE_OBJECT),
@@ -1213,7 +1213,7 @@ void renametrig(RenameStmt* stmt)
      */
     ScanKeyInit(&key[0], Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
     ScanKeyInit(&key[1], Anum_pg_trigger_tgname, BTEqualStrategyNumber, F_NAMEEQ, PointerGetDatum(stmt->subname));
-    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, SnapshotNow, 2, key);
+    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 2, key);
     if (HeapTupleIsValid(tuple = systable_getnext(tgscan))) {
         /*
          * Update pg_trigger tuple with new tgname.
@@ -1289,7 +1289,7 @@ void EnableDisableTrigger(Relation rel, const char* tgname, char fires_when, boo
     } else
         nkeys = 1;
 
-    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, SnapshotNow, nkeys, keys);
+    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, nkeys, keys);
 
     found = changed = false;
 
@@ -1383,7 +1383,7 @@ void RelationBuildTriggers(Relation relation)
         &skey, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(relation)));
 
     tgrel = heap_open(TriggerRelationId, AccessShareLock);
-    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, SnapshotNow, 1, &skey);
+    tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid(htup = systable_getnext(tgscan))) {
         Form_pg_trigger pg_trigger = (Form_pg_trigger)GETSTRUCT(htup);
@@ -4490,7 +4490,7 @@ void AfterTriggerSetState(ConstraintsSetStmt* stmt)
                     F_OIDEQ,
                     ObjectIdGetDatum(namespaceId));
 
-                conscan = systable_beginscan(conrel, ConstraintNameNspIndexId, true, SnapshotNow, 2, skey);
+                conscan = systable_beginscan(conrel, ConstraintNameNspIndexId, true, NULL, 2, skey);
 
                 while (HeapTupleIsValid(tup = systable_getnext(conscan))) {
                     Form_pg_constraint con = (Form_pg_constraint)GETSTRUCT(tup);
@@ -4543,7 +4543,7 @@ void AfterTriggerSetState(ConstraintsSetStmt* stmt)
 
             ScanKeyInit(&skey, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid));
 
-            tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true, SnapshotNow, 1, &skey);
+            tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true, NULL, 1, &skey);
 
             while (HeapTupleIsValid(htup = systable_getnext(tgscan))) {
                 Form_pg_trigger pg_trigger = (Form_pg_trigger)GETSTRUCT(htup);
@@ -5686,7 +5686,7 @@ void InvalidRelcacheForTriggerFunction(Oid funcoid, Oid returnType)
      * Find associated trigger with given function, and send invalid message to
      * the relation holding these triggers.
      */
-    sscan = systable_beginscan(trigRel, InvalidOid, false, SnapshotNow, 0, NULL);
+    sscan = systable_beginscan(trigRel, InvalidOid, false, NULL, 0, NULL);
     while (HeapTupleIsValid(tuple = systable_getnext(sscan))) {
         Form_pg_trigger trigger = (Form_pg_trigger)GETSTRUCT(tuple);
         if (trigger->tgfoid == funcoid) {
diff --git a/src/gausskernel/optimizer/commands/tsearchcmds.cpp b/src/gausskernel/optimizer/commands/tsearchcmds.cpp
index 4c3e94531..9554e25bd 100644
--- a/src/gausskernel/optimizer/commands/tsearchcmds.cpp
+++ b/src/gausskernel/optimizer/commands/tsearchcmds.cpp
@@ -1297,7 +1297,7 @@ static void makeConfigurationDependencies(HeapTuple tuple, bool removeOld, Relat
         ScanKeyInit(
             &skey, Anum_pg_ts_config_map_mapcfg, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(myself.objectId));
 
-        scan = systable_beginscan(mapRel, TSConfigMapIndexId, true, SnapshotNow, 1, &skey);
+        scan = systable_beginscan(mapRel, TSConfigMapIndexId, true, NULL, 1, &skey);
         while (HeapTupleIsValid((maptup = systable_getnext(scan)))) {
             Form_pg_ts_config_map cfgmap = (Form_pg_ts_config_map)GETSTRUCT(maptup);
 
@@ -1442,7 +1442,7 @@ void DefineTSConfiguration(List* names, List* parameters, List* cfoptions)
 
         mapRel = heap_open(TSConfigMapRelationId, RowExclusiveLock);
         ScanKeyInit(&skey, Anum_pg_ts_config_map_mapcfg, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(sourceOid));
-        scan = systable_beginscan(mapRel, TSConfigMapIndexId, true, SnapshotNow, 1, &skey);
+        scan = systable_beginscan(mapRel, TSConfigMapIndexId, true, NULL, 1, &skey);
         while (HeapTupleIsValid((maptup = systable_getnext(scan)))) {
             Form_pg_ts_config_map cfgmap = (Form_pg_ts_config_map)GETSTRUCT(maptup);
             HeapTuple newmaptup;
@@ -1598,7 +1598,7 @@ void RemoveTSConfigurationById(Oid cfgId)
     /* Remove any pg_ts_config_map entries */
     relMap = heap_open(TSConfigMapRelationId, RowExclusiveLock);
     ScanKeyInit(&skey, Anum_pg_ts_config_map_mapcfg, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(cfgId));
-    scan = systable_beginscan(relMap, TSConfigMapIndexId, true, SnapshotNow, 1, &skey);
+    scan = systable_beginscan(relMap, TSConfigMapIndexId, true, NULL, 1, &skey);
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
         simple_heap_delete(relMap, &tup->t_self);
@@ -1836,7 +1836,7 @@ static void MakeConfigurationMapping(AlterTSConfigurationStmt* stmt, HeapTuple t
                 F_INT4EQ,
                 Int32GetDatum(tokens[i]));
 
-            scan = systable_beginscan(relMap, TSConfigMapIndexId, true, SnapshotNow, 2, skey);
+            scan = systable_beginscan(relMap, TSConfigMapIndexId, true, NULL, 2, skey);
 
             while (HeapTupleIsValid((maptup = systable_getnext(scan)))) {
                 simple_heap_delete(relMap, &maptup->t_self);
@@ -1868,7 +1868,7 @@ static void MakeConfigurationMapping(AlterTSConfigurationStmt* stmt, HeapTuple t
 
         ScanKeyInit(&skey[0], Anum_pg_ts_config_map_mapcfg, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(cfgId));
 
-        scan = systable_beginscan(relMap, TSConfigMapIndexId, true, SnapshotNow, 1, skey);
+        scan = systable_beginscan(relMap, TSConfigMapIndexId, true, NULL, 1, skey);
 
         while (HeapTupleIsValid((maptup = systable_getnext(scan)))) {
             Form_pg_ts_config_map cfgmap = (Form_pg_ts_config_map)GETSTRUCT(maptup);
@@ -1969,7 +1969,7 @@ static void DropConfigurationMapping(AlterTSConfigurationStmt* stmt, HeapTuple t
         ScanKeyInit(
             &skey[1], Anum_pg_ts_config_map_maptokentype, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(tokens[i]));
 
-        scan = systable_beginscan(relMap, TSConfigMapIndexId, true, SnapshotNow, 2, skey);
+        scan = systable_beginscan(relMap, TSConfigMapIndexId, true, NULL, 2, skey);
 
         while (HeapTupleIsValid((maptup = systable_getnext(scan)))) {
             simple_heap_delete(relMap, &maptup->t_self);
diff --git a/src/gausskernel/optimizer/commands/typecmds.cpp b/src/gausskernel/optimizer/commands/typecmds.cpp
index 5f229200b..896340d5e 100644
--- a/src/gausskernel/optimizer/commands/typecmds.cpp
+++ b/src/gausskernel/optimizer/commands/typecmds.cpp
@@ -2216,7 +2216,7 @@ void AlterDomainDropConstraint(List* names, const char* constrName, DropBehavior
     ScanKeyInit(
         &key[0], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(HeapTupleGetOid(tup)));
 
-    conscan = systable_beginscan(conrel, ConstraintTypidIndexId, true, SnapshotNow, 1, key);
+    conscan = systable_beginscan(conrel, ConstraintTypidIndexId, true, NULL, 1, key);
 
     /*
      * Scan over the result set, removing any matching entries.
@@ -2394,7 +2394,7 @@ void AlterDomainValidateConstraint(List* names, char* constrName)
      */
     conrel = heap_open(ConstraintRelationId, RowExclusiveLock);
     ScanKeyInit(&key, Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(domainoid));
-    scan = systable_beginscan(conrel, ConstraintTypidIndexId, true, SnapshotNow, 1, &key);
+    scan = systable_beginscan(conrel, ConstraintTypidIndexId, true, NULL, 1, &key);
 
     while (HeapTupleIsValid(tuple = systable_getnext(scan))) {
         con = (Form_pg_constraint)GETSTRUCT(tuple);
@@ -2558,7 +2558,7 @@ static List* get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
     ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(TypeRelationId));
     ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(domainOid));
 
-    depScan = systable_beginscan(depRel, DependReferenceIndexId, true, SnapshotNow, 2, key);
+    depScan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key);
 
     while (HeapTupleIsValid(depTup = systable_getnext(depScan))) {
         Form_pg_depend pg_depend = (Form_pg_depend)GETSTRUCT(depTup);
@@ -2859,7 +2859,7 @@ List* GetDomainConstraints(Oid typeOid)
         /* Look for CHECK Constraints on this domain */
         ScanKeyInit(&key[0], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(typeOid));
 
-        scan = systable_beginscan(conRel, ConstraintTypidIndexId, true, SnapshotNow, 1, key);
+        scan = systable_beginscan(conRel, ConstraintTypidIndexId, true, NULL, 1, key);
 
         while (HeapTupleIsValid(conTup = systable_getnext(scan))) {
             Form_pg_constraint c = (Form_pg_constraint)GETSTRUCT(conTup);
diff --git a/src/gausskernel/optimizer/commands/user.cpp b/src/gausskernel/optimizer/commands/user.cpp
index cd925f248..4510c12ba 100644
--- a/src/gausskernel/optimizer/commands/user.cpp
+++ b/src/gausskernel/optimizer/commands/user.cpp
@@ -327,7 +327,7 @@ void initSqlCountUser()
     t_thrd.utils_cxt.CurrentResourceOwner = ResourceOwnerCreate(NULL, "ForSqlCount", MEMORY_CONTEXT_OPTIMIZER);
 
     Relation relation = heap_open(AuthIdRelationId, AccessShareLock);
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
     HeapTuple tup = NULL;
 
     while (HeapTupleIsValid((tup = systable_getnext(scan)))) {
@@ -3237,7 +3237,7 @@ void DropRole(DropRoleStmt* stmt)
          */
         ScanKeyInit(&scankey, Anum_pg_auth_members_roleid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(roleid));
 
-        SysScanDesc sscan = systable_beginscan(pg_auth_members_rel, AuthMemRoleMemIndexId, true, SnapshotNow, 1, &scankey);
+        SysScanDesc sscan = systable_beginscan(pg_auth_members_rel, AuthMemRoleMemIndexId, true, NULL, 1, &scankey);
         HeapTuple tmp_tuple = NULL;
         while (HeapTupleIsValid(tmp_tuple = systable_getnext(sscan))) {
             simple_heap_delete(pg_auth_members_rel, &tmp_tuple->t_self);
@@ -3247,7 +3247,7 @@ void DropRole(DropRoleStmt* stmt)
 
         ScanKeyInit(&scankey, Anum_pg_auth_members_member, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(roleid));
 
-        sscan = systable_beginscan(pg_auth_members_rel, AuthMemMemRoleIndexId, true, SnapshotNow, 1, &scankey);
+        sscan = systable_beginscan(pg_auth_members_rel, AuthMemMemRoleIndexId, true, NULL, 1, &scankey);
 
         while (HeapTupleIsValid(tmp_tuple = systable_getnext(sscan))) {
             simple_heap_delete(pg_auth_members_rel, &tmp_tuple->t_self);
@@ -4499,7 +4499,7 @@ static void AddAuthHistory(Oid roleID, const char* rolename, const char* passwd,
         fromTime = TimestampGetDatum(fromTimeDatum);
         /* get all the records from pg_auth_history of the roleID */
         ScanKeyInit(&key[0], Anum_pg_auth_history_roloid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(roleID));
-        scan = systable_beginscan(pg_auth_history_rel, AuthHistoryIndexId, true, SnapshotNow, 1, key);
+        scan = systable_beginscan(pg_auth_history_rel, AuthHistoryIndexId, true, NULL, 1, key);
 
         /* get the tuple according to reverse order of the index */
         while (HeapTupleIsValid(password_tuple = systable_getnext_back(scan))) {
@@ -4600,7 +4600,7 @@ static void DropAuthHistory(Oid roleID)
 
         ScanKeyInit(&scankey, Anum_pg_auth_history_roloid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(roleID));
 
-        sscan = systable_beginscan(pg_auth_history_rel, AuthHistoryIndexId, true, SnapshotNow, 1, &scankey);
+        sscan = systable_beginscan(pg_auth_history_rel, AuthHistoryIndexId, true, NULL, 1, &scankey);
 
         while (HeapTupleIsValid(tmp_tuple = systable_getnext(sscan))) {
             simple_heap_delete(pg_auth_history_rel, &tmp_tuple->t_self);
diff --git a/src/gausskernel/optimizer/commands/vacuum.cpp b/src/gausskernel/optimizer/commands/vacuum.cpp
index ab73bc1c6..d41e4133c 100644
--- a/src/gausskernel/optimizer/commands/vacuum.cpp
+++ b/src/gausskernel/optimizer/commands/vacuum.cpp
@@ -1237,7 +1237,7 @@ void vac_update_datfrozenxid(void)
      */
     relation = heap_open(RelationRelationId, AccessShareLock);
 
-    scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
 
     while ((classTup = systable_getnext(scan)) != NULL) {
         Form_pg_class classForm = (Form_pg_class)GETSTRUCT(classTup);
@@ -2700,7 +2700,7 @@ void CalculatePartitionedRelStats(_in_ Relation partitionRel, _in_ Relation part
         F_OIDEQ,
         ObjectIdGetDatum(RelationGetRelid(partitionRel)));
 
-    SysScanDesc partScan = systable_beginscan(partRel, PartitionParentOidIndexId, true, SnapshotNow, 2, partKey);
+    SysScanDesc partScan = systable_beginscan(partRel, PartitionParentOidIndexId, true, NULL, 2, partKey);
 
     HeapTuple partTuple = NULL;
     /* compute all pages, tuples and the minimum frozenXid */
diff --git a/src/gausskernel/optimizer/plan/planner.cpp b/src/gausskernel/optimizer/plan/planner.cpp
index ab85ed5ca..bf2fb125b 100644
--- a/src/gausskernel/optimizer/plan/planner.cpp
+++ b/src/gausskernel/optimizer/plan/planner.cpp
@@ -10704,7 +10704,7 @@ bool findConstraintByVar(Var* var, Oid relid, constraintType conType)
     ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
 
     conrel = heap_open(ConstraintRelationId, AccessShareLock);
-    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, SnapshotNow, 1, skey);
+    conscan = systable_beginscan(conrel, ConstraintRelidIndexId, true, NULL, 1, skey);
 
     /* Forantion table only can exist one information constraint now. */
     while (HeapTupleIsValid(htup = systable_getnext(conscan))) {
diff --git a/src/gausskernel/optimizer/plan/planrewrite.cpp b/src/gausskernel/optimizer/plan/planrewrite.cpp
index 44b29406c..4a3215d9a 100644
--- a/src/gausskernel/optimizer/plan/planrewrite.cpp
+++ b/src/gausskernel/optimizer/plan/planrewrite.cpp
@@ -804,7 +804,7 @@ static bool IsEqualOpr(Oid opno)
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, opno);
 
-    scan = systable_beginscan(pg_operator, OperatorOidIndexId, true, SnapshotNow, 1, skey);
+    scan = systable_beginscan(pg_operator, OperatorOidIndexId, true, NULL, 1, skey);
 
     /* Only one record should be qualified, and get the relid */
     if (HeapTupleIsValid(tuple = systable_getnext(scan))) {
diff --git a/src/gausskernel/optimizer/rewrite/rewriteRemove.cpp b/src/gausskernel/optimizer/rewrite/rewriteRemove.cpp
index 142fff4da..b01f1b38b 100644
--- a/src/gausskernel/optimizer/rewrite/rewriteRemove.cpp
+++ b/src/gausskernel/optimizer/rewrite/rewriteRemove.cpp
@@ -54,7 +54,7 @@ void RemoveRewriteRuleById(Oid ruleOid)
      */
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ruleOid));
 
-    rcscan = systable_beginscan(RewriteRelation, RewriteOidIndexId, true, SnapshotNow, 1, skey);
+    rcscan = systable_beginscan(RewriteRelation, RewriteOidIndexId, true, NULL, 1, skey);
 
     tuple = systable_getnext(rcscan);
 
diff --git a/src/gausskernel/optimizer/rewrite/rewriteSupport.cpp b/src/gausskernel/optimizer/rewrite/rewriteSupport.cpp
index fb739187a..46db8ef86 100644
--- a/src/gausskernel/optimizer/rewrite/rewriteSupport.cpp
+++ b/src/gausskernel/optimizer/rewrite/rewriteSupport.cpp
@@ -124,7 +124,7 @@ char* get_rewrite_rulename(Oid ruleid, bool missing_ok)
     errno_t rc;
     Relation rewrite_rel = heap_open(RewriteRelationId, AccessShareLock);
     ScanKeyInit(&entry, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(ruleid));
-    scan = systable_beginscan(rewrite_rel, RewriteOidIndexId, true, SnapshotNow, 1, &entry);
+    scan = systable_beginscan(rewrite_rel, RewriteOidIndexId, true, NULL, 1, &entry);
     rewrite_tup = systable_getnext(scan);
     if (!HeapTupleIsValid(rewrite_tup)) {
         if (missing_ok) {
@@ -158,7 +158,7 @@ bool rel_has_rule(Oid relid, char ev_type)
     HeapTuple rewrite_tup;
     Relation rewrite_rel = heap_open(RewriteRelationId, AccessShareLock);
     ScanKeyInit(&entry, Anum_pg_rewrite_ev_class, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid));
-    scan = systable_beginscan(rewrite_rel, RewriteRelRulenameIndexId, true, SnapshotNow, 1, &entry);
+    scan = systable_beginscan(rewrite_rel, RewriteRelRulenameIndexId, true, NULL, 1, &entry);
     while (HeapTupleIsValid((rewrite_tup = systable_getnext(scan)))) {
         Form_pg_rewrite pg_rewrite = (Form_pg_rewrite)GETSTRUCT(rewrite_tup);
         if (pg_rewrite->ev_type == ev_type) {            
diff --git a/src/gausskernel/optimizer/util/learn/encoding.cpp b/src/gausskernel/optimizer/util/learn/encoding.cpp
index e6db5ff00..a5adf6836 100644
--- a/src/gausskernel/optimizer/util/learn/encoding.cpp
+++ b/src/gausskernel/optimizer/util/learn/encoding.cpp
@@ -188,7 +188,7 @@ void SaveDataToFile(const char* filename)
 {
     Oid encodingTable = RelnameGetRelid("gs_wlm_plan_encoding_table");
     Relation relation = heap_open(encodingTable, AccessShareLock);
-    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, SnapshotNow, 0, NULL);
+    SysScanDesc scan = systable_beginscan(relation, InvalidOid, false, NULL, 0, NULL);
     HeapTuple tuple;
     TreeEncPtr enc;
     FILE* fpout = NULL;
diff --git a/src/gausskernel/process/tcop/utility.cpp b/src/gausskernel/process/tcop/utility.cpp
index e36a7b12d..51c70c6ca 100644
--- a/src/gausskernel/process/tcop/utility.cpp
+++ b/src/gausskernel/process/tcop/utility.cpp
@@ -508,7 +508,7 @@ static void check_xact_readonly(Node* parse_tree)
  */
 void PreventCommandIfReadOnly(const char* cmd_name)
 {
-    if (u_sess->attr.attr_common.XactReadOnly)
+    if (u_sess->attr.attr_common.XactReadOnly && u_sess->attr.attr_storage.replorigin_sesssion_origin == 0)
         ereport(ERROR,
             (errcode(ERRCODE_READ_ONLY_SQL_TRANSACTION),
                 /* translator: %s is name of a SQL command, eg CREATE */
diff --git a/src/gausskernel/runtime/vecexecutor/vecnode/veccstore.cpp b/src/gausskernel/runtime/vecexecutor/vecnode/veccstore.cpp
index ee10163b7..650bb1247 100644
--- a/src/gausskernel/runtime/vecexecutor/vecnode/veccstore.cpp
+++ b/src/gausskernel/runtime/vecexecutor/vecnode/veccstore.cpp
@@ -1029,7 +1029,7 @@ static CStoreStrategyNumber GetCStoreScanStrategyNumber(Oid opno)
 
     ScanKeyInit(&skey[0], ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(opno));
     hdesc = heap_open(OperatorRelationId, AccessShareLock);
-    sysscan = systable_beginscan(hdesc, OperatorOidIndexId, true, SnapshotNow, 1, skey);
+    sysscan = systable_beginscan(hdesc, OperatorOidIndexId, true, NULL, 1, skey);
 
     tuple = systable_getnext(sysscan);
     if (!HeapTupleIsValid(tuple))
diff --git a/src/gausskernel/security/gs_policy/gs_policy_audit.cpp b/src/gausskernel/security/gs_policy/gs_policy_audit.cpp
index f73340ecc..2420d454c 100644
--- a/src/gausskernel/security/gs_policy/gs_policy_audit.cpp
+++ b/src/gausskernel/security/gs_policy/gs_policy_audit.cpp
@@ -328,7 +328,7 @@ static void update_filters(const filters_set *filters_to_update, Relation policy
 
         /* Search tuple by index */
         SysScanDesc scanDesc = systable_beginscan(policy_filters_relation, GsAuditingPolicyFiltersPolicyOidIndexId, 
-                                                  true, SnapshotNow, 1, scanKey);
+                                                  true, NULL, 1, scanKey);
 
         HeapTuple auditingPolicyTuple = systable_getnext(scanDesc);
         if (!HeapTupleIsValid(auditingPolicyTuple)) {
@@ -483,7 +483,7 @@ static bool update_policy(const GsPolicyStruct *policy, Relation relation, bool
     /*
      * set up for heap-or-index scan, not need to check tgscan as systable_getnext will deal with sysscan->irel = NULL
      */
-    SysScanDesc tgscan = systable_beginscan(relation, GsAuditingPolicyOidIndexId, true, SnapshotNow, 1, &skey);
+    SysScanDesc tgscan = systable_beginscan(relation, GsAuditingPolicyOidIndexId, true, NULL, 1, &skey);
     HeapTuple tup;
     tup = systable_getnext(tgscan);
     if (!tup || !HeapTupleIsValid(tup)) {
diff --git a/src/gausskernel/security/gs_policy/gs_policy_masking.cpp b/src/gausskernel/security/gs_policy/gs_policy_masking.cpp
index 37ef226e3..5520b5007 100644
--- a/src/gausskernel/security/gs_policy/gs_policy_masking.cpp
+++ b/src/gausskernel/security/gs_policy/gs_policy_masking.cpp
@@ -142,7 +142,7 @@ void load_existing_masking_labels(policy_labelname_set *policy_labels, Oid polic
 
     /* Search tuple by index */
     SysScanDesc scanDesc = systable_beginscan(relation, GsMaskingPolicyActionsPolicyOidIndexId,
-                                              true, SnapshotNow, 1, scanKey);
+                                              true, NULL, 1, scanKey);
 
     while ((maskingPolicyTuple = systable_getnext(scanDesc)) != NULL) {
         rel_data = (Form_gs_masking_policy_actions)GETSTRUCT(maskingPolicyTuple);
@@ -442,7 +442,7 @@ static void update_masking_filters(const filters_set* filters_to_update, Relatio
         SysScanDesc scanDesc = systable_beginscan(policy_filters_relation,
                                                   GsMaskingPolicyFiltersPolicyOidIndexId,
                                                   true,
-                                                  SnapshotNow,
+                                                  NULL,
                                                   1,
                                                   scanKey);
 
@@ -486,7 +486,7 @@ static void get_policy_filter(gs_stl::gs_string *filter, Oid polid)
     SysScanDesc scanDesc = systable_beginscan(rel,
                                               GsMaskingPolicyFiltersPolicyOidIndexId, 
                                               true,
-                                              SnapshotNow,
+                                              NULL,
                                               1,
                                               scanKey);
 
@@ -736,7 +736,7 @@ static bool update_policy(const GsPolicyStruct* policy, Relation relation,
                 BTEqualStrategyNumber, F_OIDEQ,
                 ObjectIdGetDatum(policy->m_id));
 
-    SysScanDesc tgscan = systable_beginscan(relation, GsMaskingPolicyOidIndexId, true, SnapshotNow, 1, &skey);
+    SysScanDesc tgscan = systable_beginscan(relation, GsMaskingPolicyOidIndexId, true, NULL, 1, &skey);
     HeapTuple tup = NULL;
     if (tgscan == NULL) {
         (void)err_msg->append("could not scan index GsMaskingPolicyOidIndexId.");
@@ -818,7 +818,7 @@ static inline bool update_labels_in_masking_action(const PgPolicyMaskingActionSt
                 BTEqualStrategyNumber, F_OIDEQ,
                 ObjectIdGetDatum(it->second->begin()->m_id));
 
-    SysScanDesc tgscan = systable_beginscan(relation, GsMaskingPolicyActionsOidIndexId, true, SnapshotNow, 1, &skey);
+    SysScanDesc tgscan = systable_beginscan(relation, GsMaskingPolicyActionsOidIndexId, true, NULL, 1, &skey);
     HeapTuple tup = NULL;
     if (tgscan == NULL) {
         (void)err_msg->append("could not scan index GsMaskingPolicyActionsOidIndexId.");
diff --git a/src/gausskernel/security/gs_policy/gs_policy_utils.cpp b/src/gausskernel/security/gs_policy/gs_policy_utils.cpp
index b380d87f6..6ee93b854 100644
--- a/src/gausskernel/security/gs_policy/gs_policy_utils.cpp
+++ b/src/gausskernel/security/gs_policy/gs_policy_utils.cpp
@@ -223,7 +223,7 @@ bool scan_to_delete_from_relation(long long row_id, Relation relation, unsigned
                 BTEqualStrategyNumber, F_OIDEQ,
                 ObjectIdGetDatum(row_id));
 
-    SysScanDesc tgscan = systable_beginscan(relation, index_id, true, SnapshotNow, 1, &skey);
+    SysScanDesc tgscan = systable_beginscan(relation, index_id, true, NULL, 1, &skey);
 
     HeapTuple tup = systable_getnext(tgscan);
     if (!HeapTupleIsValid(tup)) {
diff --git a/src/gausskernel/security/gs_policy/policy_common.cpp b/src/gausskernel/security/gs_policy/policy_common.cpp
index 8467777b0..5151e694a 100644
--- a/src/gausskernel/security/gs_policy/policy_common.cpp
+++ b/src/gausskernel/security/gs_policy/policy_common.cpp
@@ -782,7 +782,7 @@ static void remove_policy_label(Relation relation, GsPolicyLabel *item,
     ScanKeyData skey;
     /* Find the label row to delete. */
     ScanKeyInit(&skey, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(item->m_id));
-    SysScanDesc tgscan = systable_beginscan(relation, GsPolicyLabelOidIndexId, true, SnapshotNow, 1, &skey);
+    SysScanDesc tgscan = systable_beginscan(relation, GsPolicyLabelOidIndexId, true, NULL, 1, &skey);
     HeapTuple tup = systable_getnext(tgscan);
     if (!HeapTupleIsValid(tup)) {
         ereport(ERROR, (errcode(ERRCODE_TRIGGERED_INVALID_TUPLE), 
@@ -943,7 +943,7 @@ static void remove_label(const policy_labels_set *label_resources, Relation rela
          * Find the label row to delete.
          */
         ScanKeyInit(&skey, ObjectIdAttributeNumber, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(it->m_id));
-        SysScanDesc tgscan = systable_beginscan(relation, GsPolicyLabelOidIndexId, true, SnapshotNow, 1, &skey);
+        SysScanDesc tgscan = systable_beginscan(relation, GsPolicyLabelOidIndexId, true, NULL, 1, &skey);
         HeapTuple tup = systable_getnext(tgscan);
         if (!HeapTupleIsValid(tup))
             ereport(ERROR,
diff --git a/src/gausskernel/storage/access/heap/pruneheap.cpp b/src/gausskernel/storage/access/heap/pruneheap.cpp
index e89aa9bea..e66939a7e 100644
--- a/src/gausskernel/storage/access/heap/pruneheap.cpp
+++ b/src/gausskernel/storage/access/heap/pruneheap.cpp
@@ -81,7 +81,12 @@ void heap_page_prune_opt(Relation relation, Buffer buffer)
     if (RecoveryInProgress())
         return;
 
-    oldest_xmin = u_sess->utils_cxt.RecentGlobalXmin;
+    if (IsCatalogRelation(relation) ||
+        RelationIsAccessibleInLogicalDecoding(relation)) {
+        oldest_xmin = u_sess->utils_cxt.RecentGlobalXmin;
+    } else {
+        oldest_xmin = u_sess->utils_cxt.RecentGlobalDataXmin;
+    }
 
     Assert(TransactionIdIsValid(oldest_xmin));
 
diff --git a/src/gausskernel/storage/access/index/genam.cpp b/src/gausskernel/storage/access/index/genam.cpp
index 7c1ac2a4f..0aaebebac 100644
--- a/src/gausskernel/storage/access/index/genam.cpp
+++ b/src/gausskernel/storage/access/index/genam.cpp
@@ -323,6 +323,10 @@ SysScanDesc systable_beginscan(Relation heap_relation, Oid index_id, bool index_
     } else
         irel = NULL;
 
+    if (snapshot == NULL) {
+        snapshot = GetCatalogSnapshot();
+    }
+
     sysscan = (SysScanDesc)palloc(sizeof(SysScanDescData));
 
     sysscan->heap_rel = heap_relation;
diff --git a/src/gausskernel/storage/access/transam/xloginsert.cpp b/src/gausskernel/storage/access/transam/xloginsert.cpp
index d483c6386..33256e6b8 100644
--- a/src/gausskernel/storage/access/transam/xloginsert.cpp
+++ b/src/gausskernel/storage/access/transam/xloginsert.cpp
@@ -691,6 +691,13 @@ static XLogRecData *XLogRecordAssemble(RmgrId rmid, uint8 info, XLogFPWInfo fpw_
         scratch += sizeof(XLogRecPtr);
     }
 
+    /* followed by the record's origin, if any */
+    if (u_sess->attr.attr_storage.replorigin_sesssion_origin == 0 &&
+        (u_sess->attr.attr_sql.enable_cluster_resize || t_thrd.role == AUTOVACUUM_WORKER)) {
+        t_thrd.xlog_cxt.include_origin = true;
+        u_sess->attr.attr_storage.replorigin_sesssion_origin = 1;
+    }
+
     /* followed by the record's origin, if any */
     if (t_thrd.xlog_cxt.include_origin && u_sess->attr.attr_storage.replorigin_sesssion_origin != InvalidRepOriginId) {
         *(scratch++) = XLR_BLOCK_ID_ORIGIN;
diff --git a/src/gausskernel/storage/cstore/cstore_am.cpp b/src/gausskernel/storage/cstore/cstore_am.cpp
index 4d572e2f3..02de99030 100644
--- a/src/gausskernel/storage/cstore/cstore_am.cpp
+++ b/src/gausskernel/storage/cstore/cstore_am.cpp
@@ -4720,7 +4720,7 @@ void CStoreDropColumnInCuDesc(Relation rel, AttrNumber attrnum)
     int attrno = attrnum;
     ScanKeyInit(&key[0], (AttrNumber)CUDescColIDAttr, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(attrno));
 
-    scan = systable_beginscan(cudescHeap, rel->rd_rel->relcudescidx, false, SnapshotNow, 1, key);
+    scan = systable_beginscan(cudescHeap, rel->rd_rel->relcudescidx, false, NULL, 1, key);
 
     while (HeapTupleIsValid(tup = systable_getnext(scan))) {
         simple_heap_delete(cudescHeap, &tup->t_self);
diff --git a/src/gausskernel/storage/ipc/procarray.cpp b/src/gausskernel/storage/ipc/procarray.cpp
index 2250a1d7b..f2ef25a1f 100644
--- a/src/gausskernel/storage/ipc/procarray.cpp
+++ b/src/gausskernel/storage/ipc/procarray.cpp
@@ -4090,6 +4090,7 @@ Snapshot GetLocalSnapshotData(Snapshot snapshot)
     snapshot->takenDuringRecovery = snapxid->takenDuringRecovery;
 
     TransactionId replication_slot_xmin = g_instance.proc_array_idx->replication_slot_xmin;
+    TransactionId replication_slot_catalog_xmin = g_instance.proc_array_idx->replication_slot_catalog_xmin;
 
     if (!TransactionIdIsValid(t_thrd.pgxact->xmin)) {
         t_thrd.pgxact->xmin = u_sess->utils_cxt.TransactionXmin = snapxid->xmin;
@@ -4108,6 +4109,18 @@ Snapshot GetLocalSnapshotData(Snapshot snapshot)
         TransactionIdPrecedes(replication_slot_xmin, u_sess->utils_cxt.RecentGlobalXmin))
         u_sess->utils_cxt.RecentGlobalXmin = replication_slot_xmin;
 
+    /* Non-catalog tables can be vacuumed if older than this xid */
+    u_sess->utils_cxt.RecentGlobalDataXmin = u_sess->utils_cxt.RecentGlobalXmin;
+
+    /*
+     * Check whether there's a replication slot requiring an older catalog
+     * xmin.
+     */
+    if (TransactionIdIsNormal(replication_slot_catalog_xmin) &&
+        NormalTransactionIdPrecedes(replication_slot_catalog_xmin, u_sess->utils_cxt.RecentGlobalXmin)) {
+        u_sess->utils_cxt.RecentGlobalXmin = replication_slot_catalog_xmin;
+    }
+
     u_sess->utils_cxt.RecentXmin = snapxid->xmin;
     snapshot->xmin = snapxid->xmin;
     snapshot->xmax = snapxid->xmax;
@@ -4117,8 +4130,6 @@ Snapshot GetLocalSnapshotData(Snapshot snapshot)
     snapshot->active_count = 0;
     snapshot->regd_count = 0;
     snapshot->copied = false;
-    /* Non-catalog tables can be vacuumed if older than this xid */
-    u_sess->utils_cxt.RecentGlobalDataXmin = u_sess->utils_cxt.RecentGlobalXmin;
 
     ReleaseSnapshotData(snapshot);
 
diff --git a/src/gausskernel/storage/replication/logical/decode.cpp b/src/gausskernel/storage/replication/logical/decode.cpp
index 771be2dd1..8507c7413 100644
--- a/src/gausskernel/storage/replication/logical/decode.cpp
+++ b/src/gausskernel/storage/replication/logical/decode.cpp
@@ -440,12 +440,6 @@ static void DecodeHeap3Op(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
     switch (info) {
         case XLOG_HEAP3_NEW_CID: {
-            xl_heap_new_cid *xlrec = NULL;
-            int bucket_id = 0;
-            xlrec = (xl_heap_new_cid *)buf->record_data;
-            bucket_id = XLogRecGetBucketId(buf->record);
-            SnapBuildProcessNewCid(builder, xid, buf->origptr, xlrec, bucket_id);
-
             break;
         }
         case XLOG_HEAP3_REWRITE:
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index 3deafa65a..7c39fc1c9 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -53,7 +53,7 @@ extern bool IsXidVisibleInGtmLiteLocalSnapshot(TransactionId xid, Snapshot snaps
 
 extern Snapshot GetTransactionSnapshot(bool force_local_snapshot = false);
 extern Snapshot GetLatestSnapshot(void);
-extern Snapshot GetCatalogSnapshot(Oid relid);
+extern Snapshot GetCatalogSnapshot();
 extern void SnapshotSetCommandId(CommandId curcid);
 extern Snapshot GetNonHistoricCatalogSnapshot(Oid relid);