Commit d908c8e2 authored by Bruce Momjian's avatar Bruce Momjian

Release updates suggested by Tom.

parent bcf4d356
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$Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 momjian Exp $ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.230 2003/10/31 19:24:17 momjian Exp $
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<appendix id="release"> <appendix id="release">
...@@ -18,19 +18,19 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo ...@@ -18,19 +18,19 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo
In previous releases, IN/NOT IN subqueries were joined to the In previous releases, IN/NOT IN subqueries were joined to the
upper query by sequentially scanning the subquery looking for upper query by sequentially scanning the subquery looking for
a join. The 7.4 code uses the same sophisticated techniques a join. The 7.4 code uses the same sophisticated techniques
used by ordinary joins and so is much faster, and is now faster used by ordinary joins and so is much faster. An IN
than EXISTS subqueries. will now usually as fast as or faster than an equivalent EXISTS
subquery; this reverses the conventional wisdom that applied to
previous releases.
</para> </para>
</listitem> </listitem>
<listitem><para> Improved GROUP BY processing by using hash buckets</para> <listitem><para> Improved GROUP BY processing by using hash buckets</para>
<para> <para>
In previous releases, GROUP BY totals were accumulated by In previous releases, GROUP BY values were accumulated and sorted
sequentially scanning the list of groups looking for a match; to obtain group-by counts; the 7.4 code places GROUP BY values in
the 7.4 code places GROUP BY values in hash buckets so the hash buckets so sorting is not required, or reverts to the old
proper match can be found much quicker. This is particularly behavior if the group-by buckets will not fit in memory.
significant in speeding up queries that have a large
number of distinct GROUP BY values.
</para> </para>
</listitem> </listitem>
...@@ -47,6 +47,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo ...@@ -47,6 +47,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo
specified by the query; 7.4 allows full optimization of specified by the query; 7.4 allows full optimization of
queries using ANSI join syntax, meaning the optimizer considers queries using ANSI join syntax, meaning the optimizer considers
all possible join orderings and chooses the most efficient. all possible join orderings and chooses the most efficient.
Outer joins, however, must still follow the declared ordering.
</para> </para>
</listitem> </listitem>
...@@ -72,7 +73,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo ...@@ -72,7 +73,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/release.sgml,v 1.229 2003/10/31 04:44:25 mo
<listitem><para> Full support for IPv6 connections and IPv6 address <listitem><para> Full support for IPv6 connections and IPv6 address
data types</para> data types</para>
<para> <para>
Prior releases allowed only IPv6 connections and IP data types only Prior releases allowed only IPv4 connections and IP data types only
supported IPv4 addresses. This release adds full IPv6 support in supported IPv4 addresses. This release adds full IPv6 support in
both of these areas. both of these areas.
</para> </para>
...@@ -107,9 +108,13 @@ pages, and other free space management improvements.</para> ...@@ -107,9 +108,13 @@ pages, and other free space management improvements.</para>
</para> </para>
</listitem> </listitem>
<listitem><para> New protocol improves connection speed/reliability, <listitem><para> New client-to-server protocol adds error codes, more status
and adds error codes, status information, a binary protocol, error information, better support for binary data transmission, parameter
reporting verbosity, and cleaner startup packets.</para> values separated from SQL commands, prepared statements available at the
protocol level, clean recovery from COPY failures, and cleaner startup
packets. The older protocol is still supported by both servers and
clients.
</para>
</listitem> </listitem>
<listitem><para> Allow cursors to exist outside transactions, <listitem><para> Allow cursors to exist outside transactions,
...@@ -230,6 +235,7 @@ required for those wishing to migrate data from any previous release.</para> ...@@ -230,6 +235,7 @@ required for those wishing to migrate data from any previous release.</para>
systems. systems.
</para> </para>
</listitem> </listitem>
<listitem><para>Syntax errors now reported as 'syntax error' rather than 'parse error' (Tom)</para></listitem>
</itemizedlist></para></sect2> </itemizedlist></para></sect2>
<sect2><title> Server Operation Changes</title> <sect2><title> Server Operation Changes</title>
...@@ -358,7 +364,7 @@ required for those wishing to migrate data from any previous release.</para> ...@@ -358,7 +364,7 @@ required for those wishing to migrate data from any previous release.</para>
</listitem> </listitem>
<listitem><para>Align shared buffers on 32-byte boundary for copy speed improvement (Manfred Spraul)</para> <listitem><para>Align shared buffers on 32-byte boundary for copy speed improvement (Manfred Spraul)</para>
<para> <para>
Certain CPU's perform faster data copies when addresses are 32-bit Certain CPU's perform faster data copies when addresses are 32-byte
aligned. aligned.
</para> </para>
</listitem> </listitem>
...@@ -475,17 +481,21 @@ required for those wishing to migrate data from any previous release.</para> ...@@ -475,17 +481,21 @@ required for those wishing to migrate data from any previous release.</para>
strings. strings.
</para> </para>
</listitem> </listitem>
<listitem><para>Fix subquery aggregates of upper query columns to match SQL spec. (Tom)</para> <listitem><para>Fix aggregates in subqueries to match SQL spec (Tom)</para>
<para> <para>
bjm The SQL spec says that an aggregate function appearing within a nested
subquery belongs to the outer query if its argument contains only
outer-query variables. Prior PG releases did not handle this fine point
correctly.
</para> </para>
</listitem> </listitem>
<listitem><para>Add option to prevent auto-addition of tables referenced in query (Nigel J. <listitem><para>Add option to prevent auto-addition of tables referenced in query (Nigel J.
Andrews) </para> Andrews) </para>
<para> <para>
By default, tables mentioned in the query are automatically added By default, tables mentioned in the query are automatically added
to the FROM clause if they are not already there. This option to the FROM clause if they are not already there. This is compatible with
disabled that behavior. historic Postgres behavior but is contrary to the SQL spec.
This option allows selecting spec-compatible behavior.
</para> </para>
</listitem> </listitem>
<listitem><para>Allow UPDATE ... SET col = DEFAULT (Rod)</para> <listitem><para>Allow UPDATE ... SET col = DEFAULT (Rod)</para>
...@@ -634,7 +644,7 @@ required for those wishing to migrate data from any previous release.</para> ...@@ -634,7 +644,7 @@ required for those wishing to migrate data from any previous release.</para>
the transaction aborts. the transaction aborts.
</para> </para>
</listitem> </listitem>
<listitem><para>Multiple pggla_dump fixes, including tar format and large objects</para></listitem> <listitem><para>Multiple pg_dump fixes, including tar format and large objects</para></listitem>
<listitem><para>Allow pg_dump to dump specific schemas (Neil)</para></listitem> <listitem><para>Allow pg_dump to dump specific schemas (Neil)</para></listitem>
<listitem><para>Allow pg_dump to preserve column storage characteristics (Christopher)</para> <listitem><para>Allow pg_dump to preserve column storage characteristics (Christopher)</para>
<para> <para>
......
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