index 15505f337c16f1703e42dd2dc5afed3ef18dba42..b80040d0cc265799bf772ffda4b1a8a80bbd168f 100644 (file)
@@ -4730,12 +4730,12 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008年01月01日';
<para>
It is also important to consider the overhead of partitioning during
query planning and execution. The query planner is generally able to
- handle partition hierarchies up a few thousand partitions fairly well,
- provided that typical queries allow the query planner to prune all but a
- small number of partitions. Planning times become longer and memory
+ handle partition hierarchies with up to a few thousand partitions fairly
+ well, provided that typical queries allow the query planner to prune all
+ but a small number of partitions. Planning times become longer and memory
consumption becomes higher when more partitions remain after the planner
performs partition pruning. This is particularly true for the
- <command>UPDATE</command> and <command>DELETE</command> commands. Another
+ <command>UPDATE</command> and <command>DELETE</command> commands. Another
reason to be concerned about having a large number of partitions is that
the server's memory consumption may grow significantly over a period of
time, especially if many sessions touch large numbers of partitions.