diff --git a/doc/src/sgml/mvcc.sgml b/doc/src/sgml/mvcc.sgml index 020bbcd0e2..49db3f176f 100644 --- a/doc/src/sgml/mvcc.sgml +++ b/doc/src/sgml/mvcc.sgml @@ -692,6 +692,8 @@ SELECT SUM(value) FROM mytab WHERE class = 2; SHARE, SHARE ROW EXCLUSIVE, EXCLUSIVE, and ACCESS EXCLUSIVE lock modes. + This mode protects a table against concurrent data changes, and + is self-exclusive so that only one session can hold it at a time. @@ -719,9 +721,8 @@ SELECT SUM(value) FROM mytab WHERE class = 2; - This lock mode is not automatically acquired on user tables by any - PostgreSQL command. However it is - acquired on certain system catalogs in some operations. + This lock mode is not automatically acquired on tables by any + PostgreSQL command.