rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Doc: mention that extended stats aren't used for joins 

Statistics defined by the CREATE STATISTICS command are only used to
assist with the selectivity estimations of base relations, never for
joins.  Here we mention this fact in the notes section of the CREATE
STATISTICS command.

Discussion: https://postgr.es/m/CAApHDvrMuVgDOrmg_EtFDZ=AOovq6EsJNnHH1ddyZ8EqL4yzMw@mail.gmail.com
Backpatch-through: 11
This commit is contained in:
David Rowley 2023-06-22 12:51:36 +12:00
parent 7ddba19eb7
commit 59634df871
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
doc/src/sgml/ref/create_statistics.sgml
View File

@ -125,6 +125,12 @@ CREATE STATISTICS [ IF NOT EXISTS ] <replaceable class="parameter">statistics_na
reading it. Once created, however, the ownership of the statistics
object is independent of the underlying table(s).
</para>
<para>
Extended statistics are not currently used by the planner for selectivity
estimations made for table joins. This limitation will likely be removed
in a future version of <productname>PostgreSQL</productname>.
</para>
</refsect1>
<refsect1 id="sql-createstatistics-examples">