-<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.528 2007/10/19 01:56:06 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.529 2007/10/20 16:41:09 momjian Exp $ -->
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<listitem>
<para>
- Control over whether <literal>NULL</>s sort first or last, using
- <literal>ORDER BY ... NULLS FIRST/LAST</>
+ Control over whether <literal>NULL</>s sort first or last
</para>
</listitem>
<listitem>
<para>
- Updatable cursors using <literal>UPDATE/DELETE WHERE CURRENT OF</>
+ Updatable cursors
</para>
</listitem>
<listitem>
<para>
- Numerous improvements in logging and statistics collection,
- including the ability to emit postmaster log messages in
- <acronym>CSV</> format, which can be loaded into a database
- table for analysis
+ Numerous improvements in logging and statistics collection
</para>
</listitem>
<listitem>
<para>
- Support Security Service Provider Interface (SSPI) on
- authentication for Windows and GSSAPI
+ Support Security Service Provider Interface (<acronym>SSPI</>) for
+ authentication on Windows
</para>
</listitem>
<listitem>
<para>
- Asynchronous commit option allows transactions to be committed
- but on-disk changes to be delayed
+ Asynchronous commit allows transactions to be committed but on-disk
+ changes to be delayed
</para>
</listitem>
<listitem>
<para>
- Asynchronous commit option allows transactions to be committed
- but on-disk changes to be delayed (Simon)
+ Asynchronous commit allows transactions to be committed but on-disk
+ changes to be delayed (Simon)
</para>
<para>
</para>
<para>
- To allow high concurrency <productname>PostgreSQL</> retains old
- versions of updated rows. Previously only <command>VACUUM</>
- could reuse space taken by dead rows. With <acronym>HOT</> dead
- row space can be reused at the time of <command>UPDATE</> or
- <command>INSERT</>. This allows for more consistent performance.
- <acronym>HOT</> even allows deleted row space reuse.
- <command>UPDATE</> space reuse is only possible if no modified
- columns are indexed.
+ To allow high concurrency <command>UPDATE</> creates a new tuple,
+ rather than replacing the old tuple. Previously only
+ <command>VACUUM</> could reuse space taken by old tuples. With
+ <acronym>HOT</> dead tuple space can be reused at the time of
+ <command>UPDATE</> or <command>INSERT</>. This allows for more
+ consistent performance. <acronym>HOT</> even allows deleted row
+ space reuse. <acronym>HOT</> space reuse is not possible if
+ <command>UPDATE</> changes indexed columns.
</para>
</listitem>
</para>
<para>
- This is done by scanning the table and using a filter to save
- the few requested rows, rather than sorting the entire table.
+ This is done by sequentially scanning the table and using a filter
+ to save the few requested rows, rather than sorting the entire
+ table. This is used if there is no matching index.
</para>
</listitem>
<listitem>
<para>
- Support Security Service Provider Interface (SSPI)
- authentication on Windows (Magnus)
+ Support Security Service Provider Interface (<acronym>SSPI</>) for
+ authentication on Windows
+ </para>
+
+ <para>
+ This also adds support for the <acryonym>GSSAPI</> authentication
+ <acronym>API</>.
</para>
</listitem>
Allow logfile creation in CSV format (Arul Shaji, Greg Smith,
Andrew Dunstan)
</para>
+
+ <para>
+ The CSV file can be loaded into a database table for analysis.
+ </para>
</listitem>
<listitem>
<listitem>
<para>
- Control over whether <literal>NULL</>s sort first or last, using
- <literal>ORDER BY ... NULLS FIRST/LAST</> (Teodor, Tom)
+ Control over whether <literal>NULL</>s sort first or last (Teodor, Tom)
+ </para>
+
+ <para>
+ The syntax is <literal>ORDER BY ... NULLS FIRST/LAST</>.
</para>
</listitem>
</para>
<para>
- This eliminates the need to reference a primary key to update or
- delete rows returned by a cursor.
+ This eliminates the need to reference a primary key to
+ <command>UPDATE</> or <command>DELETE</> rows returned by a cursor.
+ The syntax is <literal>UPDATE/DELETE WHERE CURRENT OF</>.
</para>
</listitem>