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Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 18447f404ce..963824d0506 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -8644,6 +8644,39 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; </listitem> </varlistentry> + <varlistentry id="guc-vacuum-failsafe-age" xreflabel="vacuum_failsafe_age"> + <term><varname>vacuum_failsafe_age</varname> (<type>integer</type>) + <indexterm> + <primary><varname>vacuum_failsafe_age</varname> configuration parameter</primary> + </indexterm> + </term> + <listitem> + <para> + Specifies the maximum age (in transactions) that a table's + <structname>pg_class</structname>.<structfield>relfrozenxid</structfield> + field can attain before <command>VACUUM</command> takes + extraordinary measures to avoid system-wide transaction ID + wraparound failure. This is <command>VACUUM</command>'s + strategy of last resort. The failsafe typically triggers + when an autovacuum to prevent transaction ID wraparound has + already been running for some time, though it's possible for + the failsafe to trigger during any <command>VACUUM</command>. + </para> + <para> + When the failsafe is triggered, any cost-based delay that is + in effect will no longer be applied, and further non-essential + maintenance tasks (such as index vacuuming) are bypassed. + </para> + <para> + The default is 1.6 billion transactions. Although users can + set this value anywhere from zero to 2.1 billion, + <command>VACUUM</command> will silently adjust the effective + value to no less than 105% of <xref + linkend="guc-autovacuum-freeze-max-age"/>. + </para> + </listitem> + </varlistentry> + <varlistentry id="guc-vacuum-multixact-freeze-table-age" xreflabel="vacuum_multixact_freeze_table_age"> <term><varname>vacuum_multixact_freeze_table_age</varname> (<type>integer</type>) <indexterm> @@ -8690,6 +8723,39 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv; </listitem> </varlistentry> + <varlistentry id="guc-multixact-failsafe-age" xreflabel="vacuum_multixact_failsafe_age"> + <term><varname>vacuum_multixact_failsafe_age</varname> (<type>integer</type>) + <indexterm> + <primary><varname>vacuum_multixact_failsafe_age</varname> configuration parameter</primary> + </indexterm> + </term> + <listitem> + <para> + Specifies the maximum age (in transactions) that a table's + <structname>pg_class</structname>.<structfield>relminmxid</structfield> + field can attain before <command>VACUUM</command> takes + extraordinary measures to avoid system-wide multixact ID + wraparound failure. This is <command>VACUUM</command>'s + strategy of last resort. The failsafe typically triggers when + an autovacuum to prevent transaction ID wraparound has already + been running for some time, though it's possible for the + failsafe to trigger during any <command>VACUUM</command>. + </para> + <para> + When the failsafe is triggered, any cost-based delay that is + in effect will no longer be applied, and further non-essential + maintenance tasks (such as index vacuuming) are bypassed. + </para> + <para> + The default is 1.6 billion multixacts. Although users can set + this value anywhere from zero to 2.1 billion, + <command>VACUUM</command> will silently adjust the effective + value to no less than 105% of <xref + linkend="guc-autovacuum-multixact-freeze-max-age"/>. + </para> + </listitem> + </varlistentry> + <varlistentry id="guc-bytea-output" xreflabel="bytea_output"> <term><varname>bytea_output</varname> (<type>enum</type>) <indexterm> |