diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ddl.sgml | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml index cdb1a07e9d3..d2082b7e88e 100644 --- a/doc/src/sgml/ddl.sgml +++ b/doc/src/sgml/ddl.sgml @@ -5075,7 +5075,13 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01'; It is possible to determine the number of partitions which were removed during this phase by observing the <quote>Subplans Removed</quote> property in the - <command>EXPLAIN</command> output. + <command>EXPLAIN</command> output. The query planner obtains locks for + all partitions which are part of the plan. However, when the executor + uses a cached plan, locks are only obtained on the partitions which + remain after partition pruning done during the initialization phase of + execution, i.e., the ones shown in the <command>EXPLAIN</command> + output and not the ones referred to by the + <quote>Subplans Removed</quote> property. </para> </listitem> |