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From slebre...@apache.org
Subject [2/3] git commit: Merge branch 'cassandra-1.2' into cassandra-2.0.0
Date Wed, 21 Aug 2013 10:16:34 GMT
Merge branch 'cassandra-1.2' into cassandra-2.0.0


Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo
Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/cd471824
Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/cd471824
Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/cd471824

Branch: refs/heads/cassandra-2.0
Commit: cd47182458623fb7b0c5b447a5f8a5eff33beac9
Parents: 7a300c2 55fed33
Author: Sylvain Lebresne <sylvain@datastax.com>
Authored: Wed Aug 21 12:15:59 2013 +0200
Committer: Sylvain Lebresne <sylvain@datastax.com>
Committed: Wed Aug 21 12:15:59 2013 +0200

----------------------------------------------------------------------
 doc/cql3/CQL.textile | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/cassandra/blob/cd471824/doc/cql3/CQL.textile
----------------------------------------------------------------------
diff --cc doc/cql3/CQL.textile
index ba90994,bb9a632..c87b9a5
--- a/doc/cql3/CQL.textile
+++ b/doc/cql3/CQL.textile
@@@ -500,11 -487,9 +502,11 @@@ WHERE movie = 'Serenity'
  
  UPDATE UserActions SET total = total + 2 WHERE user = B70DE1D0-9908-4AE3-BE34-5573E5B09F14
AND action = 'click';
  p. 
- The @UPDATE@ statement writes one or more columns for a given row in a table. The @<where-clause>@
is used to select the row to update and must include all columns composing the @PRIMARY KEY@.
Other columns values are specified through @<assignment>@ after the @SET@ keyword.
+ The @UPDATE@ statement writes one or more columns for a given row in a table. The @<where-clause>@
is used to select the row to update and must include all columns composing the @PRIMARY KEY@
(the @IN@ relation is only supported for the last column of the partition key). Other columns
values are specified through @<assignment>@ after the @SET@ keyword.
  
 -Note that unlike in SQL, @UPDATE@ does not check the prior existence of the row: the row
is created if none existed before, and updated otherwise. Furthermore, there is no mean to
know which of creation or update happened. In fact, the semantic of @INSERT@ and @UPDATE@
are identical.
 +Note that unlike in SQL, @UPDATE@ does not check the prior existence of the row by default:
the row is created if none existed before, and updated otherwise. Furthermore, there is no
mean to know which of creation or update happened.
 +
 +It is however possible to use the conditions on some columns through @IF@, in which case
the row will not be updated unless such condition are met. But please note that using @IF@
conditions will incur a non negligible performance cost (internally, Paxos will be used) so
this should be used sparingly.
  
  In an @UPDATE@ statement, all updates within the same partition key are applied atomically
and in isolation.
  


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