diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 20 | ||||
| -rw-r--r-- | doc/src/sgml/ref/alter_tablespace.sgml | 11 | ||||
| -rw-r--r-- | doc/src/sgml/ref/create_tablespace.sgml | 11 |
3 files changed, 34 insertions, 8 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 3cac340f323..672bf6f1ee7 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -2229,6 +2229,26 @@ include_dir 'conf.d' </listitem> </varlistentry> + <varlistentry id="guc-maintenance-io-concurrency" xreflabel="maintenance_io_concurrency"> + <term><varname>maintenance_io_concurrency</varname> (<type>integer</type>) + <indexterm> + <primary><varname>maintenance_io_concurrency</varname> configuration parameter</primary> + </indexterm> + </term> + <listitem> + <para> + Similar to <varname>effective_io_concurrency</varname>, but used + for maintenance work that is done on behalf of many client sessions. + </para> + <para> + The default is 10 on supported systems, otherwise 0. This value can + be overridden for tables in a particular tablespace by setting the + tablespace parameter of the same name (see + <xref linkend="sql-altertablespace"/>). + </para> + </listitem> + </varlistentry> + <varlistentry id="guc-max-worker-processes" xreflabel="max_worker_processes"> <term><varname>max_worker_processes</varname> (<type>integer</type>) <indexterm> diff --git a/doc/src/sgml/ref/alter_tablespace.sgml b/doc/src/sgml/ref/alter_tablespace.sgml index acec33469f1..356fb9f93f3 100644 --- a/doc/src/sgml/ref/alter_tablespace.sgml +++ b/doc/src/sgml/ref/alter_tablespace.sgml @@ -84,13 +84,16 @@ ALTER TABLESPACE <replaceable>name</replaceable> RESET ( <replaceable class="par <para> A tablespace parameter to be set or reset. Currently, the only available parameters are <varname>seq_page_cost</varname>, - <varname>random_page_cost</varname> and <varname>effective_io_concurrency</varname>. - Setting either value for a particular tablespace will override the + <varname>random_page_cost</varname>, <varname>effective_io_concurrency</varname> + and <varname>maintenance_io_concurrency</varname>. + Setting these values for a particular tablespace will override the planner's usual estimate of the cost of reading pages from tables in - that tablespace, as established by the configuration parameters of the + that tablespace, and the executor's prefetching behavior, as established + by the configuration parameters of the same name (see <xref linkend="guc-seq-page-cost"/>, <xref linkend="guc-random-page-cost"/>, - <xref linkend="guc-effective-io-concurrency"/>). This may be useful if + <xref linkend="guc-effective-io-concurrency"/>, + <xref linkend="guc-maintenance-io-concurrency"/>). This may be useful if one tablespace is located on a disk which is faster or slower than the remainder of the I/O subsystem. </para> diff --git a/doc/src/sgml/ref/create_tablespace.sgml b/doc/src/sgml/ref/create_tablespace.sgml index c621ec2c6bf..462b8831c27 100644 --- a/doc/src/sgml/ref/create_tablespace.sgml +++ b/doc/src/sgml/ref/create_tablespace.sgml @@ -106,13 +106,16 @@ CREATE TABLESPACE <replaceable class="parameter">tablespace_name</replaceable> <para> A tablespace parameter to be set or reset. Currently, the only available parameters are <varname>seq_page_cost</varname>, - <varname>random_page_cost</varname> and <varname>effective_io_concurrency</varname>. - Setting either value for a particular tablespace will override the + <varname>random_page_cost</varname>, <varname>effective_io_concurrency</varname> + and <varname>maintenance_io_concurrency</varname>. + Setting these values for a particular tablespace will override the planner's usual estimate of the cost of reading pages from tables in - that tablespace, as established by the configuration parameters of the + that tablespace, and the executor's prefetching behavior, as established + by the configuration parameters of the same name (see <xref linkend="guc-seq-page-cost"/>, <xref linkend="guc-random-page-cost"/>, - <xref linkend="guc-effective-io-concurrency"/>). This may be useful if + <xref linkend="guc-effective-io-concurrency"/>, + <xref linkend="guc-maintenance-io-concurrency"/>). This may be useful if one tablespace is located on a disk which is faster or slower than the remainder of the I/O subsystem. </para> |