database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-30 11:03:19 +03:00
Code Activity

Add functions pg_set_attribute_stats() and pg_clear_attribute_stats().

Browse Source 
Enable manipulation of attribute statistics. Only superficial
validation is performed, so it's possible to add nonsense, and it's up
to the planner (or other users of statistics) to behave reasonably in
that case.

Bump catalog version.

Author: Corey Huinker
Discussion: https://postgr.es/m/CADkLM=eErgzn7ECDpwFcptJKOk9SxZEk5Pot4d94eVTZsvj3gw@mail.gmail.com
This commit is contained in:
Jeff Davis
2024-10-22 15:06:55 -07:00
parent dbe6bd4343
commit ce207d2a79
11 changed files with 2263 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

72
doc/src/sgml/func.sgml
View File

@ -30222,6 +30222,78 @@ DETAIL: Make sure pg_wal_replay_wait() isn't called within a transaction with a
</para>
</entry>
</row>
<row>
<entry role="func_table_entry">
<para role="func_signature">
<indexterm>
<primary>pg_set_attribute_stats</primary>
</indexterm>
<function>pg_set_attribute_stats</function> (
<parameter>relation</parameter> <type>regclass</type>,
<parameter>attname</parameter> <type>name</type>,
<parameter>inherited</parameter> <type>boolean</type>
<optional>, <parameter>null_frac</parameter> <type>real</type></optional>
<optional>, <parameter>avg_width</parameter> <type>integer</type></optional>
<optional>, <parameter>n_distinct</parameter> <type>real</type></optional>
<optional>, <parameter>most_common_vals</parameter> <type>text</type>, <parameter>most_common_freqs</parameter> <type>real[]</type> </optional>
<optional>, <parameter>histogram_bounds</parameter> <type>text</type> </optional>
<optional>, <parameter>correlation</parameter> <type>real</type> </optional>
<optional>, <parameter>most_common_elems</parameter> <type>text</type>, <parameter>most_common_elem_freqs</parameter> <type>real[]</type> </optional>
<optional>, <parameter>elem_count_histogram</parameter> <type>real[]</type> </optional>
<optional>, <parameter>range_length_histogram</parameter> <type>text</type> </optional>
<optional>, <parameter>range_empty_frac</parameter> <type>real</type> </optional>
<optional>, <parameter>range_bounds_histogram</parameter> <type>text</type> </optional> )
<returnvalue>void</returnvalue>
</para>
<para>
Creates or updates attribute-level statistics for the given relation
and attribute name to the specified values. The parameters correspond
to to attributes of the same name found in the <link
linkend="view-pg-stats"><structname>pg_stats</structname></link>
view.
</para>
<para>
Optional parameters default to <literal>NULL</literal>, which leave
the corresponding statistic unchanged.
</para>
<para>
Ordinarily, these statistics are collected automatically or updated
as a part of <xref linkend="sql-vacuum"/> or <xref
linkend="sql-analyze"/>, so it's not necessary to call this
function. However, it may be useful when testing the effects of
statistics on the planner to understand or anticipate plan changes.
</para>
<para>
The caller must have the <literal>MAINTAIN</literal> privilege on
the table or be the owner of the database.
</para>
</entry>
</row>
<row>
<entry role="func_table_entry">
<para role="func_signature">
<indexterm>
<primary>pg_clear_attribute_stats</primary>
</indexterm>
<function>pg_clear_attribute_stats</function> (
<parameter>relation</parameter> <type>regclass</type>,
<parameter>attname</parameter> <type>name</type>,
<parameter>inherited</parameter> <type>boolean</type> )
<returnvalue>boolean</returnvalue>
</para>
<para>
Clears table-level statistics for the given relation attribute, as
though the table was newly created.
</para>
<para>
The caller must have the <literal>MAINTAIN</literal> privilege on
the table or be the owner of the database.
</para>
</entry>
</row>
</tbody>
</tgroup>
</table>