diff options
| author | Tom Lane | 2007-11-16 03:23:07 +0000 |
|---|---|---|
| committer | Tom Lane | 2007-11-16 03:23:07 +0000 |
| commit | 3b869902e09ca6a1b25d5bb548cd5efb753767ef (patch) | |
| tree | faad01b39ccff6209b3e0299aa3fc068e7e15d71 | |
| parent | b291e175a418d516010cad316d300131b980cebe (diff) | |
Add a couple of notes pointing out that GIN index build time is very
sensitive to maintenance_work_mem (something I just learned the hard
way).
| -rw-r--r-- | doc/src/sgml/gin.sgml | 15 | ||||
| -rw-r--r-- | doc/src/sgml/textsearch.sgml | 7 |
2 files changed, 20 insertions, 2 deletions
diff --git a/doc/src/sgml/gin.sgml b/doc/src/sgml/gin.sgml index d438db20a0..e0a9cb2c98 100644 --- a/doc/src/sgml/gin.sgml +++ b/doc/src/sgml/gin.sgml @@ -162,6 +162,17 @@ </varlistentry> <varlistentry> + <term><xref linkend="guc-maintenance-work-mem"></term> + <listitem> + <para> + Build time for a <acronym>GIN</acronym> index is very sensitive to + the <varname>maintenance_work_mem</> setting; it doesn't pay to + skimp on work memory during index creation. + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><xref linkend="guc-gin-fuzzy-search-limit"></term> <listitem> <para> @@ -177,8 +188,8 @@ </para> <para> To facilitate controlled execution of such queries - <acronym>GIN</acronym> has a configurable soft upper limit on the size - of the returned set, the + <acronym>GIN</acronym> has a configurable soft upper limit on the + number of rows returned, the <varname>gin_fuzzy_search_limit</varname> configuration parameter. It is set to 0 (meaning no limit) by default. If a non-zero limit is set, then the returned set is a subset of diff --git a/doc/src/sgml/textsearch.sgml b/doc/src/sgml/textsearch.sgml index 982d62a564..e54543e1c9 100644 --- a/doc/src/sgml/textsearch.sgml +++ b/doc/src/sgml/textsearch.sgml @@ -3257,6 +3257,13 @@ EXPLAIN SELECT * FROM apod WHERE textsearch @@ to_tsquery('supernovae'); </para> <para> + Note that <acronym>GIN</acronym> index build time can often be improved + by increasing <xref linkend="guc-maintenance-work-mem">, while + <acronym>GiST</acronym> index build time is not sensitive to that + parameter. + </para> + + <para> Partitioning of big collections and the proper use of GiST and GIN indexes allows the implementation of very fast searches with online update. Partitioning can be done at the database level using table inheritance |