forked from huawei/openGauss-server
796 lines
35 KiB
C
Executable File
796 lines
35 KiB
C
Executable File
/* -------------------------------------------------------------------------
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*
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* nbtree.h
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* header file for postgres btree access method implementation.
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*
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*
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* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/access/nbtree.h
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*
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* -------------------------------------------------------------------------
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*/
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#ifndef NBTREE_H
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#define NBTREE_H
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#include "access/genam.h"
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#include "access/itup.h"
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#include "access/sdir.h"
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#include "access/xlogreader.h"
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#include "catalog/pg_index.h"
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#include "lib/stringinfo.h"
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#include "storage/bufmgr.h"
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/* There's room for a 16-bit vacuum cycle ID in BTPageOpaqueData */
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typedef uint16 BTCycleId;
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/*
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* BTPageOpaqueData -- At the end of every page, we store a pointer
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* to both siblings in the tree. This is used to do forward/backward
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* index scans. The next-page link is also critical for recovery when
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* a search has navigated to the wrong page due to concurrent page splits
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* or deletions; see src/backend/access/nbtree/README for more info.
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*
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* In addition, we store the page's btree level (counting upwards from
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* zero at a leaf page) as well as some flag bits indicating the page type
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* and status. If the page is deleted, we replace the level with the
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* next-transaction-ID value indicating when it is safe to reclaim the page.
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*
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* We also store a "vacuum cycle ID". When a page is split while VACUUM is
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* processing the index, a nonzero value associated with the VACUUM run is
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* stored into both halves of the split page. (If VACUUM is not running,
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* both pages receive zero cycleids.) This allows VACUUM to detect whether
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* a page was split since it started, with a small probability of false match
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* if the page was last split some exact multiple of MAX_BT_CYCLE_ID VACUUMs
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* ago. Also, during a split, the BTP_SPLIT_END flag is cleared in the left
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* (original) page, and set in the right page, but only if the next page
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* to its right has a different cycleid.
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*
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* NOTE: the BTP_LEAF flag bit is redundant since level==0 could be tested
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* instead.
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*/
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typedef struct BTPageOpaqueDataInternal {
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BlockNumber btpo_prev; /* left sibling, or P_NONE if leftmost */
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BlockNumber btpo_next; /* right sibling, or P_NONE if rightmost */
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union {
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uint32 level; /* tree level --- zero for leaf pages */
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ShortTransactionId xact_old; /* next transaction ID, if deleted */
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} btpo;
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uint16 btpo_flags; /* flag bits, see below */
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BTCycleId btpo_cycleid; /* vacuum cycle ID of latest split */
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} BTPageOpaqueDataInternal;
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typedef BTPageOpaqueDataInternal* BTPageOpaqueInternal;
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typedef struct BTPageOpaqueData {
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BTPageOpaqueDataInternal bt_internal;
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TransactionId xact; /* next transaction ID, if deleted */
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} BTPageOpaqueData;
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typedef BTPageOpaqueData* BTPageOpaque;
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/* Bits defined in btpo_flags */
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#define BTP_LEAF (1 << 0) /* leaf page, i.e. not internal page */
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#define BTP_ROOT (1 << 1) /* root page (has no parent) */
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#define BTP_DELETED (1 << 2) /* page has been deleted from tree */
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#define BTP_META (1 << 3) /* meta-page */
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#define BTP_HALF_DEAD (1 << 4) /* empty, but still in tree */
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#define BTP_SPLIT_END (1 << 5) /* rightmost page of split group */
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#define BTP_HAS_GARBAGE (1 << 6) /* page has LP_DEAD tuples */
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#define BTP_INCOMPLETE_SPLIT (1 << 7) /* right sibling's downlink is missing */
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/*
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* The max allowed value of a cycle ID is a bit less than 64K. This is
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* for convenience of pg_filedump and similar utilities: we want to use
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* the last 2 bytes of special space as an index type indicator, and
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* restricting cycle ID lets btree use that space for vacuum cycle IDs
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* while still allowing index type to be identified.
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*/
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#define MAX_BT_CYCLE_ID 0xFF7F
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/*
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* The Meta page is always the first page in the btree index.
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* Its primary purpose is to point to the location of the btree root page.
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* We also point to the "fast" root, which is the current effective root;
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* see README for discussion.
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*/
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typedef struct BTMetaPageData {
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uint32 btm_magic; /* should contain BTREE_MAGIC */
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uint32 btm_version; /* should contain BTREE_VERSION */
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BlockNumber btm_root; /* current root location */
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uint32 btm_level; /* tree level of the root page */
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BlockNumber btm_fastroot; /* current "fast" root location */
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uint32 btm_fastlevel; /* tree level of the "fast" root page */
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} BTMetaPageData;
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#define BTPageGetMeta(p) ((BTMetaPageData*)PageGetContents(p))
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#define BTREE_METAPAGE 0 /* first page is meta */
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#define BTREE_MAGIC 0x053162 /* magic number of btree pages */
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#define BTREE_VERSION 2 /* current version number */
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/*
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* Maximum size of a btree index entry, including its tuple header.
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*
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* We actually need to be able to fit three items on every page,
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* so restrict any one item to 1/3 the per-page available space.
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*/
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#define BTMaxItemSize(page) \
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MAXALIGN_DOWN((PageGetPageSize(page) - MAXALIGN(SizeOfPageHeaderData + 3 * sizeof(ItemIdData)) - \
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MAXALIGN(sizeof(BTPageOpaqueData))) / \
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3)
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/*
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* The leaf-page fillfactor defaults to 90% but is user-adjustable.
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* For pages above the leaf level, we use a fixed 70% fillfactor.
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* The fillfactor is applied during index build and when splitting
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* a rightmost page; when splitting non-rightmost pages we try to
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* divide the data equally.
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*/
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#define BTREE_MIN_FILLFACTOR 10
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#define BTREE_DEFAULT_FILLFACTOR 90
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#define BTREE_NONLEAF_FILLFACTOR 70
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/*
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* In general, the btree code tries to localize its knowledge about
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* page layout to a couple of routines. However, we need a special
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* value to indicate "no page number" in those places where we expect
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* page numbers. We can use zero for this because we never need to
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* make a pointer to the metadata page.
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*/
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#define P_NONE 0
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/*
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* Macros to test whether a page is leftmost or rightmost on its tree level,
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* as well as other state info kept in the opaque data.
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*/
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#define P_LEFTMOST(opaque) ((opaque)->btpo_prev == P_NONE)
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#define P_RIGHTMOST(opaque) ((opaque)->btpo_next == P_NONE)
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#define P_ISLEAF(opaque) ((opaque)->btpo_flags & BTP_LEAF)
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#define P_ISROOT(opaque) ((opaque)->btpo_flags & BTP_ROOT)
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#define P_ISDELETED(opaque) ((opaque)->btpo_flags & BTP_DELETED)
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#define P_ISHALFDEAD(opaque) ((opaque)->btpo_flags & BTP_HALF_DEAD)
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#define P_IGNORE(opaque) ((opaque)->btpo_flags & (BTP_DELETED | BTP_HALF_DEAD))
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#define P_HAS_GARBAGE(opaque) ((opaque)->btpo_flags & BTP_HAS_GARBAGE)
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#define P_INCOMPLETE_SPLIT(opaque) ((opaque)->btpo_flags & BTP_INCOMPLETE_SPLIT)
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/*
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* Lehman and Yao's algorithm requires a ``high key'' on every non-rightmost
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* page. The high key is not a data key, but gives info about what range of
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* keys is supposed to be on this page. The high key on a page is required
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* to be greater than or equal to any data key that appears on the page.
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* If we find ourselves trying to insert a key > high key, we know we need
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* to move right (this should only happen if the page was split since we
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* examined the parent page).
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*
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* Our insertion algorithm guarantees that we can use the initial least key
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* on our right sibling as the high key. Once a page is created, its high
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* key changes only if the page is split.
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*
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* On a non-rightmost page, the high key lives in item 1 and data items
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* start in item 2. Rightmost pages have no high key, so we store data
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* items beginning in item 1.
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*/
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#define P_HIKEY ((OffsetNumber)1)
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#define P_FIRSTKEY ((OffsetNumber)2)
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#define P_FIRSTDATAKEY(opaque) (P_RIGHTMOST(opaque) ? P_HIKEY : P_FIRSTKEY)
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/*
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* XLOG records for btree operations
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*
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* XLOG allows to store some information in high 4 bits of log
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* record xl_info field
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*/
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#define XLOG_BTREE_INSERT_LEAF 0x00 /* add index tuple without split */
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#define XLOG_BTREE_INSERT_UPPER 0x10 /* same, on a non-leaf page */
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#define XLOG_BTREE_INSERT_META 0x20 /* same, plus update metapage */
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#define XLOG_BTREE_SPLIT_L 0x30 /* add index tuple with split */
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#define XLOG_BTREE_SPLIT_R 0x40 /* as above, new item on right */
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#define XLOG_BTREE_SPLIT_L_ROOT 0x50 /* add tuple with split of root */
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#define XLOG_BTREE_SPLIT_R_ROOT 0x60 /* as above, new item on right */
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#define XLOG_BTREE_DELETE 0x70 /* delete leaf index tuples for a page */
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#define XLOG_BTREE_DELETE_PAGE 0x80 /* delete an entire page */
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#define XLOG_BTREE_DELETE_PAGE_META 0x90 /* same, and update metapage */
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#define XLOG_BTREE_NEWROOT 0xA0 /* new root page */
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#define XLOG_BTREE_DELETE_PAGE_HALF \
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0xB0 /* page deletion that makes \
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* parent half-dead */
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#define XLOG_BTREE_VACUUM \
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0xC0 /* delete entries on a page during \
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* vacuum */
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#define XLOG_BTREE_REUSE_PAGE \
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0xD0 /* old page is about to be reused from \
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* FSM */
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/*
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* All that we need to regenerate the meta-data page
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*/
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typedef struct xl_btree_metadata {
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BlockNumber root;
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uint32 level;
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BlockNumber fastroot;
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uint32 fastlevel;
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} xl_btree_metadata;
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/*
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* This is what we need to know about simple (without split) insert.
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*
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* This data record is used for INSERT_LEAF, INSERT_UPPER, INSERT_META.
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* Note that INSERT_META implies it's not a leaf page.
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*
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* Backup Blk 0: original page (data contains the inserted tuple)
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* Backup Blk 1: xl_btree_metadata, if INSERT_META
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*/
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typedef struct xl_btree_insert {
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OffsetNumber offnum;
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} xl_btree_insert;
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#define SizeOfBtreeInsert (offsetof(xl_btree_insert, offnum) + sizeof(OffsetNumber))
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/*
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* On insert with split, we save all the items going into the right sibling
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* so that we can restore it completely from the log record. This way takes
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* less xlog space than the normal approach, because if we did it standardly,
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* XLogInsert would almost always think the right page is new and store its
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* whole page image. The left page, however, is handled in the normal
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* incremental-update fashion.
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*
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* Note: the four XLOG_BTREE_SPLIT xl_info codes all use this data record.
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* The _L and _R variants indicate whether the inserted tuple went into the
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* left or right split page (and thus, whether newitemoff and the new item
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* are stored or not). The _HIGHKEY variants indicate that we've logged
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* explicitly left page high key value, otherwise redo should use right page
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* leftmost key as a left page high key. _HIGHKEY is specified for internal
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* pages where right page leftmost key is suppressed, and for leaf pages
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* of covering indexes where high key have non-key attributes truncated.
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*
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* Backup Blk 0: original page / new left page
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*
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* The left page's data portion contains the new item, if it's the _L variant.
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* (In the _R variants, the new item is one of the right page's tuples.)
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* If level > 0, an IndexTuple representing the HIKEY of the left page
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* follows. We don't need this on leaf pages, because it's the same as the
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* leftmost key in the new right page.
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*
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* Backup Blk 1: new right page
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*
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* The right page's data portion contains the right page's tuples in the
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* form used by _bt_restore_page.
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*
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* Backup Blk 2: next block (orig page's rightlink), if any
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*/
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typedef struct xl_btree_split {
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uint32 level; /* tree level of page being split */
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OffsetNumber firstright; /* first item moved to right page */
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OffsetNumber newitemoff; /* new item's offset (if placed on left page) */
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} xl_btree_split;
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#define SizeOfBtreeSplit (offsetof(xl_btree_split, newitemoff) + sizeof(OffsetNumber))
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/*
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* This is what we need to know about delete of individual leaf index tuples.
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* The WAL record can represent deletion of any number of index tuples on a
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* single index page when *not* executed by VACUUM.
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*
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* Backup Blk 0: index page
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*/
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typedef struct xl_btree_delete {
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RelFileNodeOld hnode; /* RelFileNode of the heap the index currently
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* points at */
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int nitems;
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/* TARGET OFFSET NUMBERS FOLLOW AT THE END */
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} xl_btree_delete;
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#define SizeOfBtreeDelete (offsetof(xl_btree_delete, nitems) + sizeof(int))
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/*
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* This is what we need to know about page reuse within btree.
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*/
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typedef struct xl_btree_reuse_page {
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RelFileNodeOld node;
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BlockNumber block;
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TransactionId latestRemovedXid;
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} xl_btree_reuse_page;
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#define SizeOfBtreeReusePage (sizeof(xl_btree_reuse_page))
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/*
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* This is what we need to know about vacuum of individual leaf index tuples.
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* The WAL record can represent deletion of any number of index tuples on a
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* single index page when executed by VACUUM.
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*
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* The correctness requirement for applying these changes during recovery is
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* that we must do one of these two things for every block in the index:
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* * lock the block for cleanup and apply any required changes
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* * EnsureBlockUnpinned()
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* The purpose of this is to ensure that no index scans started before we
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* finish scanning the index are still running by the time we begin to remove
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* heap tuples.
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*
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* Any changes to any one block are registered on just one WAL record. All
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* blocks that we need to run EnsureBlockUnpinned() are listed as a block range
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* starting from the last block vacuumed through until this one. Individual
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* block numbers aren't given.
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*
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* Note that the *last* WAL record in any vacuum of an index is allowed to
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* have a zero length array of offsets. Earlier records must have at least one.
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*/
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typedef struct xl_btree_vacuum {
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BlockNumber lastBlockVacuumed;
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/* TARGET OFFSET NUMBERS FOLLOW */
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} xl_btree_vacuum;
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#define SizeOfBtreeVacuum (offsetof(xl_btree_vacuum, lastBlockVacuumed) + sizeof(BlockNumber))
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/*
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* This is what we need to know about deletion of a btree page. The target
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* identifies the tuple removed from the parent page (note that we remove
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* this tuple's downlink and the *following* tuple's key). Note we do not
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* store any content for the deleted page --- it is just rewritten as empty
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* during recovery, apart from resetting the btpo.xact.
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*
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* Backup Blk 0: target block being deleted
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* Backup Blk 1: target block's left sibling, if any
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* Backup Blk 2: target block's right sibling
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* Backup Blk 3: target block's parent
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* Backup Blk 4: metapage (if rightsib becomes new fast root)
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*/
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typedef struct xl_btree_delete_page {
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OffsetNumber poffset; /* deleted tuple id in parent page */
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BlockNumber leftblk; /* child block's left sibling, if any */
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BlockNumber rightblk; /* child block's right sibling */
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TransactionId btpo_xact; /* value of btpo.xact for use in recovery */
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/* xl_btree_metadata FOLLOWS IF XLOG_BTREE_DELETE_PAGE_META */
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} xl_btree_delete_page;
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#define SizeOfBtreeDeletePage (offsetof(xl_btree_delete_page, btpo_xact) + sizeof(TransactionId))
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/*
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* New root log record. There are zero tuples if this is to establish an
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* empty root, or two if it is the result of splitting an old root.
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*
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* Note that although this implies rewriting the metadata page, we don't need
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* an xl_btree_metadata record --- the rootblk and level are sufficient.
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*
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* Backup Blk 0: new root page (2 tuples as payload, if splitting old root)
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* Backup Blk 1: metapage
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*/
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typedef struct xl_btree_newroot {
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BlockNumber rootblk; /* location of new root (redundant with blk 0) */
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uint32 level; /* its tree level */
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/* 0 or 2 INDEX TUPLES FOLLOW AT END OF STRUCT */
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} xl_btree_newroot;
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#define SizeOfBtreeNewroot (offsetof(xl_btree_newroot, level) + sizeof(uint32))
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/*
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* INCLUDE B-Tree indexes have non-key attributes. These are extra
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* attributes that may be returned by index-only scans, but do not influence
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* the order of items in the index (formally, non-key attributes are not
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* considered to be part of the key space). Non-key attributes are only
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* present in leaf index tuples whose item pointers actually point to heap
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* tuples. All other types of index tuples (collectively, "pivot" tuples)
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* only have key attributes, since pivot tuples only ever need to represent
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* how the key space is separated. In general, any B-Tree index that has
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* more than one level (i.e. any index that does not just consist of a
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* metapage and a single leaf root page) must have some number of pivot
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* tuples, since pivot tuples are used for traversing the tree.
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*
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* We store the number of attributes present inside pivot tuples by abusing
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* their item pointer offset field, since pivot tuples never need to store a
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* real offset (downlinks only need to store a block number). The offset
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* field only stores the number of attributes when the INDEX_ALT_TID_MASK
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* bit is set (we never assume that pivot tuples must explicitly store the
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* number of attributes, and currently do not bother storing the number of
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* attributes unless indnkeyatts actually differs from indnatts).
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* INDEX_ALT_TID_MASK is only used for pivot tuples at present, though it's
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* possible that it will be used within non-pivot tuples in the future. Do
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* not assume that a tuple with INDEX_ALT_TID_MASK set must be a pivot
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* tuple.
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*
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* The 12 least significant offset bits are used to represent the number of
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* attributes in INDEX_ALT_TID_MASK tuples, leaving 4 bits that are reserved
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* for future use (BT_RESERVED_OFFSET_MASK bits). BT_N_KEYS_OFFSET_MASK should
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* be large enough to store any number <= INDEX_MAX_KEYS.
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*/
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#define INDEX_ALT_TID_MASK INDEX_AM_RESERVED_BIT
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#define BT_RESERVED_OFFSET_MASK 0xF000
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#define BT_N_KEYS_OFFSET_MASK 0x0FFF
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/* Get/set downlink block number */
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#define BTreeInnerTupleGetDownLink(itup) ItemPointerGetBlockNumberNoCheck(&((itup)->t_tid))
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#define BTreeInnerTupleSetDownLink(itup, blkno) ItemPointerSetBlockNumber(&((itup)->t_tid), (blkno))
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/*
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* Get/set leaf page highkey's link. During the second phase of deletion, the
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* target leaf page's high key may point to an ancestor page (at all other
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* times, the leaf level high key's link is not used). See the nbtree README
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* for full details.
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*/
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#define BTreeTupleGetTopParent(itup) ItemPointerGetBlockNumberNoCheck(&((itup)->t_tid))
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#define BTreeTupleSetTopParent(itup, blkno) \
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do { \
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ItemPointerSetBlockNumber(&((itup)->t_tid), (blkno)); \
|
|
BTreeTupleSetNAtts((itup), 0); \
|
|
} while (0)
|
|
|
|
/*
|
|
* Get/set number of attributes within B-tree index tuple. Asserts should be
|
|
* removed when BT_RESERVED_OFFSET_MASK bits will be used.
|
|
*/
|
|
#define BTreeTupleGetNAtts(itup, rel) \
|
|
((itup)->t_info & INDEX_ALT_TID_MASK \
|
|
? (AssertMacro((ItemPointerGetOffsetNumberNoCheck(&(itup)->t_tid) & BT_RESERVED_OFFSET_MASK) == 0), \
|
|
ItemPointerGetOffsetNumberNoCheck(&(itup)->t_tid) & BT_N_KEYS_OFFSET_MASK) \
|
|
: IndexRelationGetNumberOfAttributes(rel))
|
|
|
|
#define BTreeTupleSetNAtts(itup, n) \
|
|
do { \
|
|
(itup)->t_info |= INDEX_ALT_TID_MASK; \
|
|
Assert(((n) & BT_RESERVED_OFFSET_MASK) == 0); \
|
|
ItemPointerSetOffsetNumber(&(itup)->t_tid, (n) & BT_N_KEYS_OFFSET_MASK); \
|
|
} while (0)
|
|
|
|
/*
|
|
* Operator strategy numbers for B-tree have been moved to access/skey.h,
|
|
* because many places need to use them in ScanKeyInit() calls.
|
|
*
|
|
* The strategy numbers are chosen so that we can commute them by
|
|
* subtraction, thus:
|
|
*/
|
|
#define BTCommuteStrategyNumber(strat) (BTMaxStrategyNumber + 1 - (strat))
|
|
|
|
/*
|
|
* When a new operator class is declared, we require that the user
|
|
* supply us with an amproc procedure (BTORDER_PROC) for determining
|
|
* whether, for two keys a and b, a < b, a = b, or a > b. This routine
|
|
* must return < 0, 0, > 0, respectively, in these three cases. (It must
|
|
* not return INT_MIN, since we may negate the result before using it.)
|
|
*
|
|
* To facilitate accelerated sorting, an operator class may choose to
|
|
* offer a second procedure (BTSORTSUPPORT_PROC). For full details, see
|
|
* src/include/utils/sortsupport.h.
|
|
*/
|
|
|
|
#define BTORDER_PROC 1
|
|
#define BTSORTSUPPORT_PROC 2
|
|
|
|
/*
|
|
* We need to be able to tell the difference between read and write
|
|
* requests for pages, in order to do locking correctly.
|
|
*/
|
|
|
|
#define BT_READ BUFFER_LOCK_SHARE
|
|
#define BT_WRITE BUFFER_LOCK_EXCLUSIVE
|
|
|
|
/*
|
|
* BTStackData -- As we descend a tree, we push the (location, downlink)
|
|
* pairs from internal pages onto a private stack. If we split a
|
|
* leaf, we use this stack to walk back up the tree and insert data
|
|
* into parent pages (and possibly to split them, too). Lehman and
|
|
* Yao's update algorithm guarantees that under no circumstances can
|
|
* our private stack give us an irredeemably bad picture up the tree.
|
|
* Again, see the paper for details.
|
|
*/
|
|
|
|
typedef struct BTStackData {
|
|
BlockNumber bts_blkno;
|
|
OffsetNumber bts_offset;
|
|
BlockNumber bts_btentry;
|
|
struct BTStackData* bts_parent;
|
|
} BTStackData;
|
|
|
|
typedef BTStackData* BTStack;
|
|
|
|
/*
|
|
* BTScanOpaqueData is the btree-private state needed for an indexscan.
|
|
* This consists of preprocessed scan keys (see _bt_preprocess_keys() for
|
|
* details of the preprocessing), information about the current location
|
|
* of the scan, and information about the marked location, if any. (We use
|
|
* BTScanPosData to represent the data needed for each of current and marked
|
|
* locations.) In addition we can remember some known-killed index entries
|
|
* that must be marked before we can move off the current page.
|
|
*
|
|
* Index scans work a page at a time: we pin and read-lock the page, identify
|
|
* all the matching items on the page and save them in BTScanPosData, then
|
|
* release the read-lock while returning the items to the caller for
|
|
* processing. This approach minimizes lock/unlock traffic. Note that we
|
|
* keep the pin on the index page until the caller is done with all the items
|
|
* (this is needed for VACUUM synchronization, see nbtree/README). When we
|
|
* are ready to step to the next page, if the caller has told us any of the
|
|
* items were killed, we re-lock the page to mark them killed, then unlock.
|
|
* Finally we drop the pin and step to the next page in the appropriate
|
|
* direction.
|
|
*
|
|
* If we are doing an index-only scan, we save the entire IndexTuple for each
|
|
* matched item, otherwise only its heap TID and offset. The IndexTuples go
|
|
* into a separate workspace array; each BTScanPosItem stores its tuple's
|
|
* offset within that array.
|
|
*/
|
|
|
|
typedef struct BTScanPosItem { /* what we remember about each match */
|
|
ItemPointerData heapTid; /* TID of referenced heap item */
|
|
OffsetNumber indexOffset; /* index item's location within page */
|
|
LocationIndex tupleOffset; /* IndexTuple's offset in workspace, if any */
|
|
Oid partitionOid; /* partition table oid in workspace, if any */
|
|
} BTScanPosItem;
|
|
|
|
typedef struct BTScanPosData {
|
|
Buffer buf; /* if valid, the buffer is pinned */
|
|
|
|
BlockNumber nextPage; /* page's right link when we scanned it */
|
|
|
|
/*
|
|
* moreLeft and moreRight track whether we think there may be matching
|
|
* index entries to the left and right of the current page, respectively.
|
|
* We can clear the appropriate one of these flags when _bt_checkkeys()
|
|
* returns continuescan = false.
|
|
*/
|
|
bool moreLeft;
|
|
bool moreRight;
|
|
|
|
/*
|
|
* If we are doing an index-only scan, nextTupleOffset is the first free
|
|
* location in the associated tuple storage workspace.
|
|
*/
|
|
int nextTupleOffset;
|
|
|
|
/*
|
|
* The items array is always ordered in index order (ie, increasing
|
|
* indexoffset). When scanning backwards it is convenient to fill the
|
|
* array back-to-front, so we start at the last slot and fill downwards.
|
|
* Hence we need both a first-valid-entry and a last-valid-entry counter.
|
|
* itemIndex is a cursor showing which entry was last returned to caller.
|
|
*/
|
|
int firstItem; /* first valid index in items[] */
|
|
int lastItem; /* last valid index in items[] */
|
|
int itemIndex; /* current index in items[] */
|
|
|
|
BTScanPosItem items[MaxIndexTuplesPerPage]; /* MUST BE LAST */
|
|
} BTScanPosData;
|
|
|
|
typedef BTScanPosData* BTScanPos;
|
|
|
|
#define BTScanPosIsValid(scanpos) BufferIsValid((scanpos).buf)
|
|
|
|
/* We need one of these for each equality-type SK_SEARCHARRAY scan key */
|
|
typedef struct BTArrayKeyInfo {
|
|
int scan_key; /* index of associated key in arrayKeyData */
|
|
int cur_elem; /* index of current element in elem_values */
|
|
int mark_elem; /* index of marked element in elem_values */
|
|
int num_elems; /* number of elems in current array value */
|
|
Datum* elem_values; /* array of num_elems Datums */
|
|
} BTArrayKeyInfo;
|
|
|
|
typedef struct BTScanOpaqueData {
|
|
/* these fields are set by _bt_preprocess_keys(): */
|
|
bool qual_ok; /* false if qual can never be satisfied */
|
|
int numberOfKeys; /* number of preprocessed scan keys */
|
|
ScanKey keyData; /* array of preprocessed scan keys */
|
|
|
|
/* workspace for SK_SEARCHARRAY support */
|
|
ScanKey arrayKeyData; /* modified copy of scan->keyData */
|
|
int numArrayKeys; /* number of equality-type array keys (-1 if
|
|
* there are any unsatisfiable array keys) */
|
|
BTArrayKeyInfo* arrayKeys; /* info about each equality-type array key */
|
|
MemoryContext arrayContext; /* scan-lifespan context for array data */
|
|
|
|
/* info about killed items if any (killedItems is NULL if never used) */
|
|
int* killedItems; /* currPos.items indexes of killed items */
|
|
int numKilled; /* number of currently stored items */
|
|
|
|
/*
|
|
* If we are doing an index-only scan, these are the tuple storage
|
|
* workspaces for the currPos and markPos respectively. Each is of size
|
|
* BLCKSZ, so it can hold as much as a full page's worth of tuples.
|
|
*/
|
|
char* currTuples; /* tuple storage for currPos */
|
|
char* markTuples; /* tuple storage for markPos */
|
|
|
|
/*
|
|
* If the marked position is on the same page as current position, we
|
|
* don't use markPos, but just keep the marked itemIndex in markItemIndex
|
|
* (all the rest of currPos is valid for the mark position). Hence, to
|
|
* determine if there is a mark, first look at markItemIndex, then at
|
|
* markPos.
|
|
*/
|
|
int markItemIndex; /* itemIndex, or -1 if not valid */
|
|
|
|
/* keep these last in struct for efficiency */
|
|
BTScanPosData currPos; /* current position data */
|
|
BTScanPosData markPos; /* marked position, if any */
|
|
} BTScanOpaqueData;
|
|
|
|
typedef BTScanOpaqueData* BTScanOpaque;
|
|
|
|
/*
|
|
* We use some private sk_flags bits in preprocessed scan keys. We're allowed
|
|
* to use bits 16-31 (see skey.h). The uppermost bits are copied from the
|
|
* index's indoption[] array entry for the index attribute.
|
|
*/
|
|
#define SK_BT_REQFWD 0x00010000 /* required to continue forward scan */
|
|
#define SK_BT_REQBKWD 0x00020000 /* required to continue backward scan */
|
|
#define SK_BT_INDOPTION_SHIFT 24 /* must clear the above bits */
|
|
#define SK_BT_DESC (INDOPTION_DESC << SK_BT_INDOPTION_SHIFT)
|
|
#define SK_BT_NULLS_FIRST (INDOPTION_NULLS_FIRST << SK_BT_INDOPTION_SHIFT)
|
|
|
|
// BTPageState and BTWriteState are moved here from nbtsort.cpp
|
|
/*
|
|
* Status record for a btree page being built. We have one of these
|
|
* for each active tree level.
|
|
*
|
|
* The reason we need to store a copy of the minimum key is that we'll
|
|
* need to propagate it to the parent node when this page is linked
|
|
* into its parent. However, if the page is not a leaf page, the first
|
|
* entry on the page doesn't need to contain a key, so we will not have
|
|
* stored the key itself on the page. (You might think we could skip
|
|
* copying the minimum key on leaf pages, but actually we must have a
|
|
* writable copy anyway because we'll poke the page's address into it
|
|
* before passing it up to the parent...)
|
|
*/
|
|
typedef struct BTPageState {
|
|
Page btps_page; /* workspace for page building */
|
|
BlockNumber btps_blkno; /* block # to write this page at */
|
|
IndexTuple btps_minkey; /* copy of minimum key (first item) on page */
|
|
OffsetNumber btps_lastoff; /* last item offset loaded */
|
|
uint32 btps_level; /* tree level (0 = leaf) */
|
|
Size btps_full; /* "full" if less than this much free space */
|
|
struct BTPageState* btps_next; /* link to parent level, if any */
|
|
} BTPageState;
|
|
|
|
/*
|
|
* Overall status record for index writing phase.
|
|
*/
|
|
typedef struct BTWriteState {
|
|
Relation index;
|
|
bool btws_use_wal; /* dump pages to WAL? */
|
|
BlockNumber btws_pages_alloced; /* # pages allocated */
|
|
BlockNumber btws_pages_written; /* # pages written out */
|
|
Page btws_zeropage; /* workspace for filling zeroes */
|
|
} BTWriteState;
|
|
|
|
typedef struct BTOrderedIndexListElement {
|
|
IndexTuple itup;
|
|
BlockNumber heapModifiedOffset;
|
|
IndexScanDesc indexScanDesc;
|
|
} BTOrderedIndexListElement;
|
|
|
|
/*
|
|
* prototypes for functions in nbtree.c (external entry points for btree)
|
|
*/
|
|
extern Datum btbuild(PG_FUNCTION_ARGS);
|
|
extern Datum btbuildempty(PG_FUNCTION_ARGS);
|
|
extern Datum btinsert(PG_FUNCTION_ARGS);
|
|
extern Datum btbeginscan(PG_FUNCTION_ARGS);
|
|
extern Datum btgettuple(PG_FUNCTION_ARGS);
|
|
extern Datum btgetbitmap(PG_FUNCTION_ARGS);
|
|
extern Datum cbtreegetbitmap(PG_FUNCTION_ARGS);
|
|
extern Datum btrescan(PG_FUNCTION_ARGS);
|
|
extern Datum btendscan(PG_FUNCTION_ARGS);
|
|
extern Datum btmarkpos(PG_FUNCTION_ARGS);
|
|
extern Datum btrestrpos(PG_FUNCTION_ARGS);
|
|
extern Datum btbulkdelete(PG_FUNCTION_ARGS);
|
|
extern Datum btvacuumcleanup(PG_FUNCTION_ARGS);
|
|
extern Datum btcanreturn(PG_FUNCTION_ARGS);
|
|
extern Datum btoptions(PG_FUNCTION_ARGS);
|
|
/*
|
|
* this is the interface of merge 2 or more index for btree index
|
|
* we also have similar interfaces for other kind of indexes, like hash/gist/gin
|
|
* thought, we are not going to implement them right now.
|
|
*/
|
|
extern Datum btmerge(PG_FUNCTION_ARGS);
|
|
|
|
/*
|
|
* prototypes for functions in nbtinsert.c
|
|
*/
|
|
extern bool _bt_doinsert(Relation rel, IndexTuple itup, IndexUniqueCheck checkUnique, Relation heapRel);
|
|
extern Buffer _bt_getstackbuf(Relation rel, BTStack stack, int access);
|
|
|
|
/*
|
|
* prototypes for functions in nbtpage.c
|
|
*/
|
|
extern void _bt_initmetapage(Page page, BlockNumber rootbknum, uint32 level);
|
|
extern Buffer _bt_getroot(Relation rel, int access);
|
|
extern Buffer _bt_gettrueroot(Relation rel);
|
|
extern void _bt_checkpage(Relation rel, Buffer buf);
|
|
extern Buffer _bt_getbuf(Relation rel, BlockNumber blkno, int access);
|
|
extern Buffer _bt_relandgetbuf(Relation rel, Buffer obuf, BlockNumber blkno, int access);
|
|
extern void _bt_relbuf(Relation rel, Buffer buf);
|
|
extern void _bt_pageinit(Page page, Size size);
|
|
extern bool _bt_page_recyclable(Page page);
|
|
extern void _bt_delitems_delete(Relation rel, Buffer buf, OffsetNumber* itemnos, int nitems, Relation heapRel);
|
|
extern void _bt_delitems_vacuum(
|
|
Relation rel, Buffer buf, OffsetNumber* itemnos, int nitems, BlockNumber lastBlockVacuumed);
|
|
extern int _bt_pagedel(Relation rel, Buffer buf, BTStack stack);
|
|
extern void _bt_page_localupgrade(Page page);
|
|
/*
|
|
* prototypes for functions in nbtsearch.c
|
|
*/
|
|
extern BTStack _bt_search(
|
|
Relation rel, int keysz, ScanKey scankey, bool nextkey, Buffer* bufP, int access, bool needStack = true);
|
|
extern Buffer _bt_moveright(Relation rel, Buffer buf, int keysz, ScanKey scankey, bool nextkey, bool forupdate, BTStack stack, int access);
|
|
extern OffsetNumber _bt_binsrch(Relation rel, Buffer buf, int keysz, ScanKey scankey, bool nextkey);
|
|
extern int32 _bt_compare(Relation rel, int keysz, ScanKey scankey, Page page, OffsetNumber offnum);
|
|
extern bool _bt_first(IndexScanDesc scan, ScanDirection dir);
|
|
extern bool _bt_next(IndexScanDesc scan, ScanDirection dir);
|
|
extern Buffer _bt_get_endpoint(Relation rel, uint32 level, bool rightmost);
|
|
extern bool _bt_gettuple_internal(IndexScanDesc scan, ScanDirection dir);
|
|
extern bool _bt_check_natts(const Relation index, Page page, OffsetNumber offnum);
|
|
|
|
/*
|
|
* prototypes for functions in nbtutils.c
|
|
*/
|
|
extern ScanKey _bt_mkscankey(Relation rel, IndexTuple itup);
|
|
extern ScanKey _bt_mkscankey_nodata(Relation rel);
|
|
extern void _bt_freeskey(ScanKey skey);
|
|
extern void _bt_freestack(BTStack stack);
|
|
extern void _bt_preprocess_array_keys(IndexScanDesc scan);
|
|
extern void _bt_start_array_keys(IndexScanDesc scan, ScanDirection dir);
|
|
extern bool _bt_advance_array_keys(IndexScanDesc scan, ScanDirection dir);
|
|
extern void _bt_mark_array_keys(IndexScanDesc scan);
|
|
extern void _bt_restore_array_keys(IndexScanDesc scan);
|
|
extern void _bt_preprocess_keys(IndexScanDesc scan);
|
|
extern IndexTuple _bt_checkkeys(
|
|
IndexScanDesc scan, Page page, OffsetNumber offnum, ScanDirection dir, bool* continuescan);
|
|
extern void _bt_killitems(IndexScanDesc scan, bool haveLock);
|
|
extern BTCycleId _bt_vacuum_cycleid(Relation rel);
|
|
extern BTCycleId _bt_start_vacuum(Relation rel);
|
|
extern void _bt_end_vacuum(Relation rel);
|
|
extern void _bt_end_vacuum_callback(int code, Datum arg);
|
|
extern Size BTreeShmemSize(void);
|
|
extern void BTreeShmemInit(void);
|
|
extern void _bt_finish_split(Relation rel, Buffer lbuf, BTStack stack);
|
|
extern IndexTuple _bt_nonkey_truncate(Relation idxrel, IndexTuple olditup);
|
|
|
|
/*
|
|
* prototypes for functions in nbtsort.c
|
|
*/
|
|
typedef struct BTSpool BTSpool; /* opaque type known only within nbtsort.c */
|
|
|
|
/* Working state for btbuild and its callback */
|
|
typedef struct {
|
|
bool isUnique;
|
|
bool haveDead;
|
|
Relation heapRel;
|
|
BTSpool* spool;
|
|
|
|
/*
|
|
* spool2 is needed only when the index is an unique index. Dead tuples
|
|
* are put into spool2 instead of spool in order to avoid uniqueness
|
|
* check.
|
|
*/
|
|
BTSpool* spool2;
|
|
double indtuples;
|
|
} BTBuildState;
|
|
|
|
extern BTSpool* _bt_spoolinit(Relation index, bool isunique, bool isdead, void* meminfo);
|
|
extern void _bt_spooldestroy(BTSpool* btspool);
|
|
extern void _bt_spool(BTSpool* btspool, ItemPointer self, Datum* values, const bool* isnull);
|
|
extern void _bt_leafbuild(BTSpool* btspool, BTSpool* spool2);
|
|
/* these 4 functions are move here from nbtsearch.cpp(static functions) */
|
|
extern void _bt_buildadd(BTWriteState* wstate, BTPageState* state, IndexTuple itup);
|
|
extern void _bt_uppershutdown(BTWriteState* wstate, BTPageState* state);
|
|
BTPageState* _bt_pagestate(BTWriteState* wstate, uint32 level);
|
|
extern bool _index_tuple_compare(TupleDesc tupdes, ScanKey indexScanKey, int keysz, IndexTuple itup, IndexTuple itup2);
|
|
extern List* insert_ordered_index(List* list, TupleDesc tupdes, ScanKey indexScanKey, int keysz, IndexTuple itup,
|
|
BlockNumber heapModifiedOffset, IndexScanDesc srcIdxRelScan);
|
|
/*
|
|
* prototypes for functions in nbtxlog.c
|
|
*/
|
|
extern void btree_redo(XLogReaderState* record);
|
|
extern void btree_desc(StringInfo buf, XLogReaderState* record);
|
|
extern void btree_xlog_startup(void);
|
|
extern void* BTreeGetIncompleteActions();
|
|
extern bool IsBtreeVacuum(const XLogReaderState* record);
|
|
extern void _bt_restore_page(Page page, char* from, int len);
|
|
extern void DumpBtreeDeleteInfo(XLogRecPtr lsn, OffsetNumber offsetList[], uint64 offsetNum);
|
|
|
|
#endif /* NBTREE_H */
|