Add an index entry for "Performance Tips". Patch from Alvaro Herrera.

doc/src/sgml/perform.sgml

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-$PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.45 2004/04/22 17:38:14 neilc Exp $
+$PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.46 2004/05/27 01:00:40 neilc Exp $
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  <chapter id="performance-tips">
   <title>Performance Tips</title>
 
+  <indexterm zone="performance-tips">
+   <primary>performance</primary>
+  </indexterm>
+
   <para>
    Query performance can be affected by many things. Some of these can 
    be manipulated by the user, while others are fundamental to the underlying