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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 >Indexes</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="The SQL Language" HREF="sql.html"><LINK REL="PREVIOUS" TITLE="UNION, CASE, and Related Constructs" HREF="typeconv-union-case.html"><LINK REL="NEXT" TITLE="Introduction" HREF="indexes-intro.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="CHAPTER" ><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="UNION, CASE, and Related Constructs" HREF="typeconv-union-case.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="sql.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="Introduction" HREF="indexes-intro.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="INDEXES" ></A >Chapter 11. Indexes</H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT >11.1. <A HREF="indexes-intro.html" >Introduction</A ></DT ><DT >11.2. <A HREF="indexes-types.html" >Index Types</A ></DT ><DT >11.3. <A HREF="indexes-multicolumn.html" >Multicolumn Indexes</A ></DT ><DT >11.4. <A HREF="indexes-ordering.html" >Indexes and <TT CLASS="LITERAL" >ORDER BY</TT ></A ></DT ><DT >11.5. <A HREF="indexes-bitmap-scans.html" >Combining Multiple Indexes</A ></DT ><DT >11.6. <A HREF="indexes-unique.html" >Unique Indexes</A ></DT ><DT >11.7. <A HREF="indexes-expressional.html" >Indexes on Expressions</A ></DT ><DT >11.8. <A HREF="indexes-partial.html" >Partial Indexes</A ></DT ><DT >11.9. <A HREF="indexes-opclass.html" >Operator Classes and Operator Families</A ></DT ><DT >11.10. <A HREF="indexes-collations.html" >Indexes and Collations</A ></DT ><DT >11.11. <A HREF="indexes-examine.html" >Examining Index Usage</A ></DT ></DL ></DIV ><P > Indexes are a common way to enhance database performance. An index allows the database server to find and retrieve specific rows much faster than it could do without an index. But indexes also add overhead to the database system as a whole, so they should be used sensibly. </P ></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="typeconv-union-case.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="indexes-intro.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><TT CLASS="LITERAL" >UNION</TT >, <TT CLASS="LITERAL" >CASE</TT >, and Related Constructs</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="sql.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Introduction</TD ></TR ></TABLE ></DIV ></BODY ></HTML >