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diff --git a/doc/src/sgml/btree-gin.sgml b/doc/src/sgml/btree-gin.sgml new file mode 100644 index 0000000..4611720 --- /dev/null +++ b/doc/src/sgml/btree-gin.sgml @@ -0,0 +1,66 @@ +<!-- doc/src/sgml/btree-gin.sgml --> + +<sect1 id="btree-gin" xreflabel="btree_gin"> + <title>btree_gin — GIN operator classes with B-tree behavior</title> + + <indexterm zone="btree-gin"> + <primary>btree_gin</primary> + </indexterm> + + <para> + <filename>btree_gin</filename> provides GIN operator classes that + implement B-tree equivalent behavior for the data types + <type>int2</type>, <type>int4</type>, <type>int8</type>, <type>float4</type>, + <type>float8</type>, <type>timestamp with time zone</type>, + <type>timestamp without time zone</type>, <type>time with time zone</type>, + <type>time without time zone</type>, <type>date</type>, <type>interval</type>, + <type>oid</type>, <type>money</type>, <type>"char"</type>, + <type>varchar</type>, <type>text</type>, <type>bytea</type>, <type>bit</type>, + <type>varbit</type>, <type>macaddr</type>, <type>macaddr8</type>, <type>inet</type>, + <type>cidr</type>, <type>uuid</type>, <type>name</type>, <type>bool</type>, + <type>bpchar</type>, and all <type>enum</type> types. + </para> + + <para> + In general, these operator classes will not outperform the equivalent + standard B-tree index methods, and they lack one major feature of the + standard B-tree code: the ability to enforce uniqueness. However, + they are useful for GIN testing and as a base for developing other + GIN operator classes. Also, for queries that test both a GIN-indexable + column and a B-tree-indexable column, it might be more efficient to create + a multicolumn GIN index that uses one of these operator classes than to create + two separate indexes that would have to be combined via bitmap ANDing. + </para> + + <para> + This module is considered <quote>trusted</quote>, that is, it can be + installed by non-superusers who have <literal>CREATE</literal> privilege + on the current database. + </para> + + <sect2 id="btree-gin-example-usage"> + <title>Example Usage</title> + +<programlisting> +CREATE TABLE test (a int4); +-- create index +CREATE INDEX testidx ON test USING GIN (a); +-- query +SELECT * FROM test WHERE a < 10; +</programlisting> + + </sect2> + + <sect2 id="btree-gin-authors"> + <title>Authors</title> + + <para> + Teodor Sigaev (<email>teodor@stack.net</email>) and + Oleg Bartunov (<email>oleg@sai.msu.su</email>). See + <ulink url="http://www.sai.msu.su/~megera/oddmuse/index.cgi/Gin"></ulink> + for additional information. + </para> + + </sect2> + +</sect1> |