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authorBruce Momjian2022-09-03 03:32:19 +0000
committerBruce Momjian2022-09-03 03:32:19 +0000
commit75d5712452ee887e938535001f9efef337c644d9 (patch)
tree46cf87f1790a109a99dcdc37fba3214377b2181f
parent8ec6a4ef3c3a6aa08f2cc235fab8c691a8b2f341 (diff)
doc: simplify docs about analyze and inheritance/partitions
Discussion: https://postgr.es/m/[email protected] Backpatch-through: 10
-rw-r--r--doc/src/sgml/ref/analyze.sgml22
1 files changed, 7 insertions, 15 deletions
diff --git a/doc/src/sgml/ref/analyze.sgml b/doc/src/sgml/ref/analyze.sgml
index b968f740cb..2ba115d1ad 100644
--- a/doc/src/sgml/ref/analyze.sgml
+++ b/doc/src/sgml/ref/analyze.sgml
@@ -250,12 +250,13 @@ ANALYZE [ VERBOSE ] [ <replaceable class="parameter">table_and_columns</replacea
</para>
<para>
- If the table being analyzed has one or more children,
- <command>ANALYZE</command> will gather statistics twice: once on the
- rows of the parent table only, and a second time on the rows of the
- parent table with all of its children. This second set of statistics
- is needed when planning queries that traverse the entire inheritance
- tree. The autovacuum daemon, however, will only consider inserts or
+ If the table being analyzed has inheritance children,
+ <command>ANALYZE</command> gathers two sets of statistics: one on the rows
+ of the parent table only, and a second including rows of both the parent
+ table and all of its children. This second set of statistics is needed when
+ planning queries that process the inheritance tree as a whole. The child
+ tables themselves are not individually analyzed in this case.
+ The autovacuum daemon, however, will only consider inserts or
updates on the parent table itself when deciding whether to trigger an
automatic analyze for that table. If that table is rarely inserted into
or updated, the inheritance statistics will not be up to date unless you
@@ -272,15 +273,6 @@ ANALYZE [ VERBOSE ] [ <replaceable class="parameter">table_and_columns</replacea
</para>
<para>
- By contrast, if the table being analyzed has inheritance children,
- <command>ANALYZE</command> gathers two sets of statistics: one on the rows
- of the parent table only, and a second including rows of both the parent
- table and all of its children. This second set of statistics is needed when
- planning queries that process the inheritance tree as a whole. The child
- tables themselves are not individually analyzed in this case.
- </para>
-
- <para>
The autovacuum daemon does not process partitioned tables, nor does it
process inheritance parents if only the children are ever modified.
It is usually necessary to periodically run a manual