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Release updates suggested by Tom.
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@ -1,5 +1,5 @@
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<!--
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$Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 momjian Exp $
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$Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.230 2003/10/31 19:24:17 momjian Exp $
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-->
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<appendix id="release">
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@ -18,19 +18,19 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo
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In previous releases, IN/NOT IN subqueries were joined to the
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upper query by sequentially scanning the subquery looking for
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a join. The 7.4 code uses the same sophisticated techniques
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used by ordinary joins and so is much faster, and is now faster
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than EXISTS subqueries.
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used by ordinary joins and so is much faster. An IN
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will now usually as fast as or faster than an equivalent EXISTS
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subquery; this reverses the conventional wisdom that applied to
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previous releases.
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</para>
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</listitem>
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<listitem><para> Improved GROUP BY processing by using hash buckets</para>
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<para>
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In previous releases, GROUP BY totals were accumulated by
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sequentially scanning the list of groups looking for a match;
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the 7.4 code places GROUP BY values in hash buckets so the
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proper match can be found much quicker. This is particularly
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significant in speeding up queries that have a large
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number of distinct GROUP BY values.
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In previous releases, GROUP BY values were accumulated and sorted
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to obtain group-by counts; the 7.4 code places GROUP BY values in
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hash buckets so sorting is not required, or reverts to the old
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behavior if the group-by buckets will not fit in memory.
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</para>
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</listitem>
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@ -47,6 +47,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo
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specified by the query; 7.4 allows full optimization of
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queries using ANSI join syntax, meaning the optimizer considers
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all possible join orderings and chooses the most efficient.
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Outer joins, however, must still follow the declared ordering.
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</para>
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</listitem>
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@ -72,7 +73,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo
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<listitem><para> Full support for IPv6 connections and IPv6 address
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data types</para>
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<para>
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Prior releases allowed only IPv6 connections and IP data types only
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Prior releases allowed only IPv4 connections and IP data types only
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supported IPv4 addresses. This release adds full IPv6 support in
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both of these areas.
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</para>
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@ -107,9 +108,13 @@ pages, and other free space management improvements.</para>
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</para>
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</listitem>
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<listitem><para> New protocol improves connection speed/reliability,
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and adds error codes, status information, a binary protocol, error
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reporting verbosity, and cleaner startup packets.</para>
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<listitem><para> New client-to-server protocol adds error codes, more status
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information, better support for binary data transmission, parameter
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values separated from SQL commands, prepared statements available at the
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protocol level, clean recovery from COPY failures, and cleaner startup
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packets. The older protocol is still supported by both servers and
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clients.
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</para>
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</listitem>
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<listitem><para> Allow cursors to exist outside transactions,
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@ -230,6 +235,7 @@ required for those wishing to migrate data from any previous release.</para>
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systems.
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</para>
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</listitem>
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<listitem><para>Syntax errors now reported as 'syntax error' rather than 'parse error' (Tom)</para></listitem>
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</itemizedlist></para></sect2>
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<sect2><title> Server Operation Changes</title>
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@ -358,7 +364,7 @@ required for those wishing to migrate data from any previous release.</para>
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</listitem>
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<listitem><para>Align shared buffers on 32-byte boundary for copy speed improvement (Manfred Spraul)</para>
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<para>
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Certain CPU's perform faster data copies when addresses are 32-bit
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Certain CPU's perform faster data copies when addresses are 32-byte
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aligned.
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</para>
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</listitem>
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@ -475,17 +481,21 @@ required for those wishing to migrate data from any previous release.</para>
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strings.
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</para>
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</listitem>
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<listitem><para>Fix subquery aggregates of upper query columns to match SQL spec. (Tom)</para>
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<listitem><para>Fix aggregates in subqueries to match SQL spec (Tom)</para>
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<para>
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bjm
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The SQL spec says that an aggregate function appearing within a nested
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subquery belongs to the outer query if its argument contains only
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outer-query variables. Prior PG releases did not handle this fine point
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correctly.
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</para>
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</listitem>
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<listitem><para>Add option to prevent auto-addition of tables referenced in query (Nigel J.
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Andrews) </para>
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<para>
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By default, tables mentioned in the query are automatically added
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to the FROM clause if they are not already there. This option
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disabled that behavior.
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to the FROM clause if they are not already there. This is compatible with
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historic Postgres behavior but is contrary to the SQL spec.
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This option allows selecting spec-compatible behavior.
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</para>
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</listitem>
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<listitem><para>Allow UPDATE ... SET col = DEFAULT (Rod)</para>
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@ -634,7 +644,7 @@ required for those wishing to migrate data from any previous release.</para>
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the transaction aborts.
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</para>
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</listitem>
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<listitem><para>Multiple pggla_dump fixes, including tar format and large objects</para></listitem>
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<listitem><para>Multiple pg_dump fixes, including tar format and large objects</para></listitem>
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<listitem><para>Allow pg_dump to dump specific schemas (Neil)</para></listitem>
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<listitem><para>Allow pg_dump to preserve column storage characteristics (Christopher)</para>
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<para>
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