doc: Add description about re-analysis and re-planning of a prepared statement.

A prepared statement is re-analyzed and re-planned whenever database
objects used in the statement have undergone definitional changes or
the planner statistics of them have been updated. The former has been
documented from before, but the latter was not previously. This commit
adds the description about the latter case into the docs.

Author: Atsushi Torikoshi
Reviewed-by: Andy Fan, Fujii Masao
Discussion: https://postgr.es/m/3ac82f4817c9fe274a905c8a38d87bd9@oss.nttdata.com
This commit is contained in:
Fujii Masao 2020-11-26 16:17:10 +09:00
parent f3a8f73ec2
commit 4a36eab79a

View File

@ -184,7 +184,8 @@ EXPLAIN EXECUTE <replaceable>name</replaceable>(<replaceable>parameter_values</r
analysis and planning of the statement, <productname>PostgreSQL</productname> will
force re-analysis and re-planning of the statement before using it
whenever database objects used in the statement have undergone
definitional (DDL) changes since the previous use of the prepared
definitional (DDL) changes or the planner statistics of them have
been updated since the previous use of the prepared
statement. Also, if the value of <xref linkend="guc-search-path"/> changes
from one use to the next, the statement will be re-parsed using the new
<varname>search_path</varname>. (This latter behavior is new as of