postgres.git / summary / log / commit / refs

commit    4e17cb00dc2b57f0ac1bbe3c1fd587e982b33307
Author:   David Rowley <drowley@postgresql.org>
Date:     Thu Jun 22 00:47:15 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 e3e5c297ddb..a145c41f04b 100644
--- a/doc/src/sgml/ref/create_statistics.sgml
+++ b/doc/src/sgml/ref/create_statistics.sgml
@@ -167,6 +167,12 @@ CREATE STATISTICS [ IF NOT EXISTS ] <replaceable class="parameter">statistics_na
    maintenance. Expression statistics are built automatically for each
    expression in the statistics object definition.
   </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: 642bec1f8dd2]