<para>

Users should now use hstore(text, text). Since

<productname>PostgreSQL</productname> 9.0,we have emitted a

warning message when an operator named =&gt; is created because

<productname>PostgreSQL</productname> 9.0,a warning message is

emitted when an operator named =&gt; is created because

the <acronym>SQL</acronym> standard reserves that token for

another use.

</para>

</para>

</listitem>

<listitem>

<para>

Make the visibility map crash-safe (Robert Haas, Noah Misch)

</para>

<para>

This helps vacuum be more efficient, and is necessary for

index-only scans.

</para>

</listitem>

<listitem>

<para>

Improve GiST box and point index performance by producing better

<listitem>

<para>

Improve performance of <acronym>WAL</acronym> writes when multiple

transactions commit at the same time (Peter Geoghegan, Simon Riggs,

Heikki Linnakangas)

Improve performance of <acronym>WAL</acronym> writes using group

commit (Peter Geoghegan, Simon Riggs, Heikki Linnakangas)

</para>

</listitem>

<listitem>

<para>

Make the visibility map crash-safe (Robert Haas, Noah Misch)

</para>

<para>

This helps vacuum be more efficient, and is necessary for

index-only scans.

</para>

</listitem>

<listitem>

<para>

Allow the <link linkend="pg-stat-bgwriter-view">bgwriter</link>,

<link linkend="guc-wal-writer-delay">walwriter</link>,and<link

linkend="monitoring-stats">statistics collector</link> to sleep

more efficiently during periods of inactivity (Peter Geoghegan,

Heikki Linnakangas, Tom Lane)

<link linkend="guc-wal-writer-delay">walwriter</link>, <link

linkend="monitoring-stats">statistics collector</link>, archiver,

and checkpointer to sleepmore efficiently during periods of

inactivity (Peter Geoghegan,Heikki Linnakangas, Tom Lane)

</para>

<para>

This reduces <acronym>CPU</acronym> wake-ups.

This reduces <acronym>CPU</acronym> wake-ups, which dramatically

reduces power consumption on idle servers.

</para>

</listitem>

</para>

<para>

We already supported minor-version-specific <filename>.psqlrc</>

<application>psql</> already supported minor-version-specific

<filename>.psqlrc</>

files.

</para>

</listitem>

<para>

Specifically, only lock the old cluster if link mode is used,

and do it right afterwe restorethe schema.

and do it right after the schema is restored.

</para>

</listitem>