Update documentation to mention that autovacuum also does analyze so we

don't need to recommend nightly analyzes anymore unless autovacuum is off.
This commit is contained in:
Bruce Momjian 2007-09-14 13:43:03 +00:00
parent fc79628641
commit 13e26073bd
1 changed files with 14 additions and 7 deletions

View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.80 2007/09/14 02:43:18 momjian Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/maintenance.sgml,v 1.81 2007/09/14 13:43:03 momjian Exp $ -->
<chapter id="maintenance">
<title>Routine Database Maintenance Tasks</title>
@ -262,12 +262,19 @@
</tip>
<para>
Recommended practice for most sites is to schedule a database-wide
<command>ANALYZE</> once a day at a low-usage time of day; this can
usefully be combined with a nightly <command>VACUUM</>. However,
sites with relatively slowly changing table statistics might find that
this is overkill, and that less-frequent <command>ANALYZE</> runs
are sufficient.
Fortunately, autovacuum (<xref linkend="autovacuum">) monitors table
activity and performs <command>ANALYZE</command>s when necessary. This
eliminates the need for administrators to manually schedule
<command>ANALYZE</command>.
</para>
<para>
For those not using autovacuum, one approach is to schedule a
database-wide <command>ANALYZE</> once a day at a low-usage time of
day; this can usefully be combined with a nightly <command>VACUUM</>.
However, sites with relatively slowly changing table statistics might
find that this is overkill, and that less-frequent <command>ANALYZE</>
runs are sufficient.
</para>
</sect2>