<para>

The new option is called <literal>NOT VALID</>, which can

later be modified to <literal>VALIDATED</> and validation

checks performed.

checks performed. Together these allow you to add a Foreign Key

with minimal impact on read and write operations.

</para>

</listitem>

</para>

<para>

This feature can be used to implement updatable views.

This feature can be used to implementfullyupdatable views.

</para>

</listitem>

<listitem>

<para>

Reduce lock levels for <link

Minimise lock levels for <link

linkend="SQL-CREATETRIGGER"><command>CREATE TRIGGER</></link>

andsome <link linkend="SQL-ALTERTABLE"><command>ALTER

andmany <link linkend="SQL-ALTERTABLE"><command>ALTER

TABLE</></link> and <link linkend="SQL-CREATERULE"><command>CREATE

RULE</></link> operations (Simon Riggs)

</para>

<para>

This improvesconcurrency.

This improvesdatabase availability when altering active databases.

</para>

</listitem>

</para>

</listitem>

<listitem>

<para>

Extensive proofreading and documentation improvements

(Thom Brown, Josh Kupershmidt, Susanne Ebrecht)

</para>

</listitem>

<listitem>

<para>

Add documentation for <link