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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >btree_gin</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 9.2.24 Documentation" HREF="index.html"><LINK REL="UP" TITLE="Additional Supplied Modules" HREF="contrib.html"><LINK REL="PREVIOUS" TITLE="auto_explain" HREF="auto-explain.html"><LINK REL="NEXT" TITLE="btree_gist" HREF="btree-gist.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2017-11-06T22:43:11"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.2.24 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="auto_explain" HREF="auto-explain.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="contrib.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Appendix F. Additional Supplied Modules</TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="btree_gist" HREF="btree-gist.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="BTREE-GIN" >F.4. btree_gin</A ></H1 ><P > <TT CLASS="FILENAME" >btree_gin</TT > provides sample GIN operator classes that implement B-tree equivalent behavior for the data types <TT CLASS="TYPE" >int2</TT >, <TT CLASS="TYPE" >int4</TT >, <TT CLASS="TYPE" >int8</TT >, <TT CLASS="TYPE" >float4</TT >, <TT CLASS="TYPE" >float8</TT >, <TT CLASS="TYPE" >timestamp with time zone</TT >, <TT CLASS="TYPE" >timestamp without time zone</TT >, <TT CLASS="TYPE" >time with time zone</TT >, <TT CLASS="TYPE" >time without time zone</TT >, <TT CLASS="TYPE" >date</TT >, <TT CLASS="TYPE" >interval</TT >, <TT CLASS="TYPE" >oid</TT >, <TT CLASS="TYPE" >money</TT >, <TT CLASS="TYPE" >"char"</TT >, <TT CLASS="TYPE" >varchar</TT >, <TT CLASS="TYPE" >text</TT >, <TT CLASS="TYPE" >bytea</TT >, <TT CLASS="TYPE" >bit</TT >, <TT CLASS="TYPE" >varbit</TT >, <TT CLASS="TYPE" >macaddr</TT >, <TT CLASS="TYPE" >inet</TT >, and <TT CLASS="TYPE" >cidr</TT >. </P ><P > 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. </P ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN146660" >F.4.1. Example Usage</A ></H2 ><PRE CLASS="PROGRAMLISTING" >CREATE TABLE test (a int4); -- create index CREATE INDEX testidx ON test USING gin (a); -- query SELECT * FROM test WHERE a < 10;</PRE ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN146663" >F.4.2. Authors</A ></H2 ><P > Teodor Sigaev (<CODE CLASS="EMAIL" ><<A HREF="mailto:teodor@stack.net" >teodor@stack.net</A >></CODE >) and Oleg Bartunov (<CODE CLASS="EMAIL" ><<A HREF="mailto:oleg@sai.msu.su" >oleg@sai.msu.su</A >></CODE >). See <A HREF="http://www.sai.msu.su/~megera/oddmuse/index.cgi/Gin" TARGET="_top" >http://www.sai.msu.su/~megera/oddmuse/index.cgi/Gin</A > for additional information. </P ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="auto-explain.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="btree-gist.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >auto_explain</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="contrib.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >btree_gist</TD ></TR ></TABLE ></DIV ></BODY ></HTML >