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$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.370 2005/09/22 23:24:58 momjian Exp $

$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.371 2005/09/22 23:47:44 momjian Exp $

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</varlistentry>

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<term>

Improve performance for partitioned tables (Simon)

</term>

<listitem>

<para>

The new <varname>constraint_exclusion</varname> configuration

parameter avoids lookups on child tables where constraints indicate

that no matching rows exist in the child table.

</para>

<para>

This allows for a basic type of table partitioning. If child tables

store separate key ranges and this is enforced using appropriate

<command>CHECK</> constraints, the optimizer will skip child

table accesses when the constraint guarantees no matching rows

exist in the child table.

</para>

</listitem>

</varlistentry>

</variablelist>

</sect2>

</para>

</listitem>

<listitem>

<para>

Add <varname>constraint_exclusion</varname> configuration

parameter to restrict child table lookups based on table

constraints (Simon)

</para>

<para>

This allows for a basic type of table partitioning. If child tables

store separate key ranges and this is enforced using appropriate

<command>CHECK</> constraints, the optimizer will skip child

table accesses when the constraint guarantees no matching rows

exist in the child table.

</para>

</listitem>

<listitem>

<para>

Use <literal>O_DIRECT</> if available when using