diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/vacuum.sgml | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/doc/src/sgml/ref/vacuum.sgml b/doc/src/sgml/ref/vacuum.sgml index 442977a50d5..a48f75ad7ba 100644 --- a/doc/src/sgml/ref/vacuum.sgml +++ b/doc/src/sgml/ref/vacuum.sgml @@ -235,22 +235,22 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet Perform index vacuum and index cleanup phases of <command>VACUUM</command> in parallel using <replaceable class="parameter">integer</replaceable> background workers (for the details of each vacuum phase, please - refer to <xref linkend="vacuum-phases"/>). If the - <literal>PARALLEL</literal> option is omitted, then the number of workers - is determined based on the number of indexes that support parallel vacuum - operation on the relation, and is further limited by <xref - linkend="guc-max-parallel-workers-maintenance"/>. - An index can participate in parallel vacuum if and only if the size - of the index is more than <xref linkend="guc-min-parallel-index-scan-size"/>. - Please note that it is not guaranteed that the number of parallel workers - specified in <replaceable class="parameter">integer</replaceable> will - be used during execution. It is possible for a vacuum to run with fewer - workers than specified, or even with no workers at all. Only one worker - can be used per index. So parallel workers are launched only when there - are at least <literal>2</literal> indexes in the table. Workers for - vacuum are launched before the start of each phase and exit at the end of - the phase. These behaviors might change in a future release. This - option can't be used with the <literal>FULL</literal> option. + refer to <xref linkend="vacuum-phases"/>). In plain <command>VACUUM</command> + (without <literal>FULL</literal>), if the <literal>PARALLEL</literal> option + is omitted, then the number of workers is determined based on the number of + indexes on the relation that support parallel vacuum operation and is further + limited by <xref linkend="guc-max-parallel-workers-maintenance"/>. An index + can participate in parallel vacuum if and only if the size of the index is + more than <xref linkend="guc-min-parallel-index-scan-size"/>. Please note + that it is not guaranteed that the number of parallel workers specified in + <replaceable class="parameter">integer</replaceable> will be used during + execution. It is possible for a vacuum to run with fewer workers than + specified, or even with no workers at all. Only one worker can be used per + index. So parallel workers are launched only when there are at least + <literal>2</literal> indexes in the table. Workers for vacuum are launched + before the start of each phase and exit at the end of the phase. These + behaviors might change in a future release. This option can't be used with + the <literal>FULL</literal> option. </para> </listitem> </varlistentry> |