<listitem>

<para>

<emphasis>Allow a table's row type to be cast to the table's supertype

if it's a type table.</emphasis>

if it's a type table</emphasis>

</para>

<para>

This is analagous to the existing facility that allows casting a row

<listitem>

<para>

<emphasis>Make foreign data wrappers functional, and support FOREIGN

TABLEs.</emphasis>

TABLEs</emphasis>

</para>

<para>

Foreign tables are component of SQL/MED, and provide a framework to

<listitem>

<para>

<emphasis>Allow a unique or primary key constraint to be created

using an existing index.</emphasis>

using an existing index</emphasis>

</para>

</listitem>

<listitem>

<para>

<emphasis>Implement Serializable Snapshot Isolation, in order to

provide a more robust serializable transaction mode.</emphasis>

provide a more robust serializable transaction mode</emphasis>

</para>

<para>

In previous releases, the REPEATABLE READ and SERIALIZABLE isolation

<listitem>

<para>

<emphasis>Teach ALTER TABLE .. SET DATA TYPE to avoid a table write

<emphasis>Teach ALTER TABLE ... SET DATA TYPE to avoid a table write

in some cases where it isn't necessary

</emphasis>

</para>

<listitem>

<para>

<emphasis>Support unlogged tables.</emphasis>

<emphasis>Support unlogged tables</emphasis>

</para>

<para>

The contents of an unlogged table are not WAL-logged; thus, they

<listitem>

<para>

<emphasis>Hash joins now support right and full outer joins.</emphasis>

<emphasis>Hash joins now support right and full outer joins</emphasis>

</para>

<para>

Previously, full joins could be implemented only as a merge join,

<listitem>

<para>

Support host names and host key

word <literal>all</literal>

Support host names and host key word <literal>all</literal>

in <filename>pg_hba.conf</filename>

</para>

</listitem>

<para>

<emphasis>When an autovacuum worker (other than one performing an

anti-wraparound vacuum) is unable to obtain a lock on the target

relation without blocking, skip the relation.</emphasis>

relation without blocking, skip the relation</emphasis>

</para>

<para>

This avoids pinning down an autovacuum worker. The next autovacuum

<listitem>

<para>

<emphasis>Add REPLICATION privilege for ROLEs.</emphasis>

<emphasis>Add REPLICATION privilege for ROLEs</emphasis>

</para>

<para>

This makes it possible for replication to be performed by a

<listitem>

<para>

<emphasis>Change pg_last_xlog_receive_location not to move

backwards.</emphasis>

backwards</emphasis>

</para>

</listitem>