natas_hw
/
cassandra
mirror of https://github.com/apache/cassandra
0
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Merge branch 'cassandra-2.2' into cassandra-3.0

This commit is contained in:
Sylvain Lebresne 2015-12-22 11:54:21 +01:00
parent 21103bea23 e654c1bf04
commit 450fca99df
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
doc/cql3/CQL.textile
View File

@ -982,7 +982,7 @@ APPLY BATCH;
The @BATCH@ statement group multiple modification statements (insertions/updates and deletions) into a single statement. It serves several purposes:
# It saves network round-trips between the client and the server (and sometimes between the server coordinator and the replicas) when batching multiple updates.
# All updates in a @BATCH@ belonging to a given partition key are performed in isolation.
# By default, all operations in the batch are performed atomically. See the notes on "@UNLOGGED@":#unloggedBatch for more details.
# By default, all operations in the batch are performed as @LOGGED@, to ensure all mutations eventually complete (or none will). See the notes on "@UNLOGGED@":#unloggedBatch for more details.
Note that:
* @BATCH@ statements may only contain @UPDATE@, @INSERT@ and @DELETE@ statements.
@ -991,9 +991,9 @@ Note that:
h4(#unloggedBatch). @UNLOGGED@
By default, Cassandra uses a batch log to ensure all operations in a batch are applied atomically. (Note that the operations are still only isolated within a single partition.)
By default, Cassandra uses a batch log to ensure all operations in a batch eventually complete or none will (note however that operations are only isolated within a single partition).
There is a performance penalty for batch atomicity when a batch spans multiple partitions. If you do not want to incur this penalty, you can tell Cassandra to skip the batchlog with the @UNLOGGED@ option. If the @UNLOGGED@ option is used, operations are only atomic within a single partition.
There is a performance penalty for batch atomicity when a batch spans multiple partitions. If you do not want to incur this penalty, you can tell Cassandra to skip the batchlog with the @UNLOGGED@ option. If the @UNLOGGED@ option is used, a failed batch might leave the patch only partly applied.
h4(#counterBatch). @COUNTER@