postgres.git / summary / log / commit / refs

commit    59634df871a4a63af679ddace44ded7492fd83bc
Author:   David Rowley <drowley@postgresql.org>
Date:     Thu Jun 22 00:51:36 2023 +0000
First released in: 16.0, 11.21, 12.16, 13.12, 14.9, 15.4

    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


 doc/src/sgml/ref/create_statistics.sgml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/doc/src/sgml/ref/create_statistics.sgml b/doc/src/sgml/ref/create_statistics.sgml
index 8770470cee1..330bdc6494a 100644
--- a/doc/src/sgml/ref/create_statistics.sgml
+++ b/doc/src/sgml/ref/create_statistics.sgml
@@ -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">


[parent: 7ddba19eb711]