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Increase the default value of default_statistics_target from 10 to 100,

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and its maximum value from 1000 to 10000.  ALTER TABLE SET STATISTICS
similarly now allows a value up to 10000.  Per discussion.
This commit is contained in:
Tom Lane
2008-12-13 19:13:44 +00:00
parent b69bde7749
commit 65e3ea7641
9 changed files with 27 additions and 27 deletions
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4
doc/src/sgml/ref/alter_table.sgml
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@@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.101 2008/11/14 10:22:45 petere Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.102 2008/12/13 19:13:44 tgl Exp $
PostgreSQL documentation
-->
@@ -142,7 +142,7 @@ where <replaceable class="PARAMETER">action</replaceable> is one of:
This form
sets the per-column statistics-gathering target for subsequent
<xref linkend="sql-analyze" endterm="sql-analyze-title"> operations.
The target can be set in the range 0 to 1000; alternatively, set it
The target can be set in the range 0 to 10000; alternatively, set it
to -1 to revert to using the system default statistics
target (<xref linkend="guc-default-statistics-target">).
For more information on the use of statistics by the

12
doc/src/sgml/ref/analyze.sgml
View File

@@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/analyze.sgml,v 1.24 2008/11/14 10:22:45 petere Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/analyze.sgml,v 1.25 2008/12/13 19:13:44 tgl Exp $
PostgreSQL documentation
-->
@@ -132,10 +132,10 @@ ANALYZE [ VERBOSE ] [ <replaceable class="PARAMETER">table</replaceable> [ ( <re
will change slightly each time <command>ANALYZE</command> is run,
even if the actual table contents did not change. This might result
in small changes in the planner's estimated costs shown by
<xref linkend="sql-explain" endterm="sql-explain-title">. In rare situations, this
non-determinism will cause the query optimizer to choose a
different query plan between runs of <command>ANALYZE</command>. To
avoid this, raise the amount of statistics collected by
<xref linkend="sql-explain" endterm="sql-explain-title">.
In rare situations, this non-determinism will cause the planner's
choices of query plans to change after <command>ANALYZE</command> is run.
To avoid this, raise the amount of statistics collected by
<command>ANALYZE</command>, as described below.
</para>
@@ -148,7 +148,7 @@ ANALYZE [ VERBOSE ] [ <replaceable class="PARAMETER">table</replaceable> [ ( <re
endterm="sql-altertable-title">). The target value sets the
maximum number of entries in the most-common-value list and the
maximum number of bins in the histogram. The default target value
is 10, but this can be adjusted up or down to trade off accuracy of
is 100, but this can be adjusted up or down to trade off accuracy of
planner estimates against the time taken for
<command>ANALYZE</command> and the amount of space occupied in
<literal>pg_statistic</literal>. In particular, setting the