diff options
| author | Alvaro Herrera <alvherre@alvh.no-ip.org> | 2015-09-08 12:51:42 -0300 |
|---|---|---|
| committer | Alvaro Herrera <alvherre@alvh.no-ip.org> | 2015-09-08 12:51:42 -0300 |
| commit | 1aba62ec635f5852bc45ce65482366e541e61ff5 (patch) | |
| tree | 1161cc00324cb8d229b831a944432646ae1552d5 /doc/src/sgml/ref/create_tablespace.sgml | |
| parent | 665a00c9e2598e3be366cb9f99c0a04a51dd8c7a (diff) | |
| download | postgresql-1aba62ec635f5852bc45ce65482366e541e61ff5.tar.gz postgresql-1aba62ec635f5852bc45ce65482366e541e61ff5.zip | |
Allow per-tablespace effective_io_concurrency
Per discussion, nowadays it is possible to have tablespaces that have
wildly different I/O characteristics from others. Setting different
effective_io_concurrency parameters for those has been measured to
improve performance.
Author: Julien Rouhaud
Reviewed by: Andres Freund
Diffstat (limited to 'doc/src/sgml/ref/create_tablespace.sgml')
| -rw-r--r-- | doc/src/sgml/ref/create_tablespace.sgml | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/doc/src/sgml/ref/create_tablespace.sgml b/doc/src/sgml/ref/create_tablespace.sgml index 5756c3e080f..cf08408f961 100644 --- a/doc/src/sgml/ref/create_tablespace.sgml +++ b/doc/src/sgml/ref/create_tablespace.sgml @@ -104,14 +104,15 @@ CREATE TABLESPACE <replaceable class="parameter">tablespace_name</replaceable> <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 + available parameters are <varname>seq_page_cost</>, + <varname>random_page_cost</> and <varname>effective_io_concurrency</>. + 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">, + <xref linkend="guc-effective-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> </listitem> |