diff options
Diffstat (limited to 'doc/src/sgml')
| -rw-r--r-- | doc/src/sgml/config.sgml | 11 | ||||
| -rw-r--r-- | doc/src/sgml/ref/alter_tablespace.sgml | 22 |
2 files changed, 31 insertions, 2 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index df8f858c545..34f472555e5 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.241 2009/12/25 01:09:31 rhaas Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.242 2010/01/05 21:53:58 rhaas Exp $ --> <chapter Id="runtime-config"> <title>Server Configuration</title> @@ -2000,6 +2000,9 @@ archive_command = 'copy "%p" "C:\\server\\archivedir\\%f"' # Windows <para> Sets the planner's estimate of the cost of a disk page fetch that is part of a series of sequential fetches. The default is 1.0. + This value can be overriden for a particular tablespace by setting + the tablespace parameter of the same name + (see <xref linkend="sql-altertablespace">). </para> </listitem> </varlistentry> @@ -2013,6 +2016,12 @@ archive_command = 'copy "%p" "C:\\server\\archivedir\\%f"' # Windows <para> Sets the planner's estimate of the cost of a non-sequentially-fetched disk page. The default is 4.0. + This value can be overriden for a particular tablespace by setting + the tablespace parameter of the same name + (see <xref linkend="sql-altertablespace">). + </para> + + <para> Reducing this value relative to <varname>seq_page_cost</> will cause the system to prefer index scans; raising it will make index scans look relatively more expensive. You can raise diff --git a/doc/src/sgml/ref/alter_tablespace.sgml b/doc/src/sgml/ref/alter_tablespace.sgml index 8c5341dd084..758ee13aa69 100644 --- a/doc/src/sgml/ref/alter_tablespace.sgml +++ b/doc/src/sgml/ref/alter_tablespace.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/alter_tablespace.sgml,v 1.5 2009/09/19 10:23:26 petere Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/alter_tablespace.sgml,v 1.6 2010/01/05 21:53:58 rhaas Exp $ PostgreSQL documentation --> @@ -23,6 +23,8 @@ PostgreSQL documentation <synopsis> ALTER TABLESPACE <replaceable>name</replaceable> RENAME TO <replaceable>new_name</replaceable> ALTER TABLESPACE <replaceable>name</replaceable> OWNER TO <replaceable>new_owner</replaceable> +ALTER TABLESPACE <replaceable>name</replaceable> SET ( <replaceable class="PARAMETER">tablespace_option</replaceable> = <replaceable class="PARAMETER">value</replaceable> [, ... ] ) +ALTER TABLESPACE <replaceable>name</replaceable> RESET ( <replaceable class="PARAMETER">tablespace_option</replaceable> [, ... ] ) </synopsis> </refsynopsisdiv> @@ -74,6 +76,24 @@ ALTER TABLESPACE <replaceable>name</replaceable> OWNER TO <replaceable>new_owner </para> </listitem> </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">tablespace_parameter</replaceable></term> + <listitem> + <para> + A tablespace parameter to be set or reset. Currently, the only + available parameters are <varname>seq_page_cost</> and + <varname>random_page_cost</>. Setting either value 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 same name (see + <xref linkend="guc-seq-page-cost">, + <xref linkend="guc-random-page-cost">). 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> + </listitem> + </varlistentry> </variablelist> </refsect1> |