diff options
| author | Fujii Masao <fujii@postgresql.org> | 2019-05-08 02:10:33 +0900 |
|---|---|---|
| committer | Fujii Masao <fujii@postgresql.org> | 2019-05-08 02:10:33 +0900 |
| commit | b84dbc8eb80b43e554891c459a19969d9fbdefe5 (patch) | |
| tree | 3005b4dc1ca54c9ce9fd3c2d24b69ec12b680111 /doc/src | |
| parent | 98719af6c2e30d538cd05cfe044f58ba4067b52b (diff) | |
| download | postgresql-b84dbc8eb80b43e554891c459a19969d9fbdefe5.tar.gz postgresql-b84dbc8eb80b43e554891c459a19969d9fbdefe5.zip | |
Add TRUNCATE parameter to VACUUM.
This commit adds new parameter to VACUUM command, TRUNCATE,
which specifies that VACUUM should attempt to truncate off
any empty pages at the end of the table and allow the disk space
for the truncated pages to be returned to the operating system.
This parameter, if specified, overrides the vacuum_truncate
reloption. If neither the reloption nor the VACUUM option is
used, the default is true, as before.
Author: Fujii Masao
Reviewed-by: Julien Rouhaud, Masahiko Sawada
Discussion: https://postgr.es/m/CAD21AoD+qtrSDL=GSma4Wd3kLYLeRC0hPna-YAdkDeV4z156vg@mail.gmail.com
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/create_table.sgml | 6 | ||||
| -rw-r--r-- | doc/src/sgml/ref/vacuum.sgml | 19 |
2 files changed, 23 insertions, 2 deletions
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index 786510f94ca..19af4eed9c3 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -1418,7 +1418,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM Disabling index cleanup can speed up <command>VACUUM</command> very significantly, but may also lead to severely bloated indexes if table modifications are frequent. The <literal>INDEX_CLEANUP</literal> - parameter to <xref linkend="sql-vacuum"/>, if specified, overrides + parameter of <xref linkend="sql-vacuum"/>, if specified, overrides the value of this option. </para> </listitem> @@ -1438,7 +1438,9 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM autovacuum do the truncation and the disk space for the truncated pages is returned to the operating system. Note that the truncation requires <literal>ACCESS EXCLUSIVE</literal> - lock on the table. + lock on the table. The <literal>TRUNCATE</literal> parameter + of <xref linkend="sql-vacuum"/>, if specified, overrides the value + of this option. </para> </listitem> </varlistentry> diff --git a/doc/src/sgml/ref/vacuum.sgml b/doc/src/sgml/ref/vacuum.sgml index c652f8b0bcd..f9b0fb87945 100644 --- a/doc/src/sgml/ref/vacuum.sgml +++ b/doc/src/sgml/ref/vacuum.sgml @@ -33,6 +33,7 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet DISABLE_PAGE_SKIPPING [ <replaceable class="parameter">boolean</replaceable> ] SKIP_LOCKED [ <replaceable class="parameter">boolean</replaceable> ] INDEX_CLEANUP [ <replaceable class="parameter">boolean</replaceable> ] + TRUNCATE [ <replaceable class="parameter">boolean</replaceable> ] <phrase>and <replaceable class="parameter">table_and_columns</replaceable> is:</phrase> @@ -205,6 +206,24 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet </varlistentry> <varlistentry> + <term><literal>TRUNCATE</literal></term> + <listitem> + <para> + Specifies that <command>VACUUM</command> should attempt to + truncate off any empty pages at the end of the table and allow + the disk space for the truncated pages to be returned to + the operating system. This is normally the desired behavior + and is the default unless the <literal>vacuum_truncate</literal> + option has been set to false for the table to be vacuumed. + Setting this option to false may be useful to avoid + <literal>ACCESS EXCLUSIVE</literal> lock on the table that + the truncation requires. This option is ignored if the + <literal>FULL</literal> option is used. + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><replaceable class="parameter">boolean</replaceable></term> <listitem> <para> |