From c46f861c0dde5813b8c472a65dfc4e76d093ad0f Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Thu, 10 Jun 2010 21:48:28 +0000
Subject: [PATCH] Update text of 9.0 release notes
Josh Berkus
---
doc/src/sgml/release-9.0.sgml | 250 ++++++++++++++++++----------------
1 file changed, 133 insertions(+), 117 deletions(-)
diff --git a/doc/src/sgml/release-9.0.sgml b/doc/src/sgml/release-9.0.sgml
index 8777a2c9040..e5002c13415 100644
--- a/doc/src/sgml/release-9.0.sgml
+++ b/doc/src/sgml/release-9.0.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/release-9.0.sgml,v 2.28 2010/06/07 02:01:08 itagaki Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/release-9.0.sgml,v 2.29 2010/06/10 21:48:28 momjian Exp $ -->
<sect1 id="release-9-0">
<title>Release 9.0</title>
@@ -8,10 +8,6 @@
<simpara>2010-??-??</simpara>
</note>
-<!-- beta2 notes
-recovery_connections -> hot_standby
--->
-
<sect2>
<title>Overview</title>
@@ -32,123 +28,78 @@ recovery_connections -> hot_standby
<!-- This list duplicates items below, but without authors or details-->
<listitem>
- <para>
- Allow continuous archive standby systems to accept read-only queries
- </para>
- </listitem>
-
- <listitem>
- <para>
- Allow continuous archive (<acronym>WAL</>) files to be streamed to a
- standby system
- </para>
- </listitem>
-
- <listitem>
- <para>
- Add the ability to make mass permission changes per
- schema using the new <link
- linkend="SQL-GRANT"><command>GRANT</>/<command>REVOKE
- IN SCHEMA</></link> clause
- </para>
- </listitem>
-
- <listitem>
- <para>
- Add the ability to control large object permissions with
- <command>GRANT</>/<command>REVOKE</>
- </para>
- </listitem>
-
- <listitem>
- <para>
- Implement anonymous functions using the <link
- linkend="SQL-DO"><command>DO</></link> statement
- </para>
- </listitem>
-
- <listitem>
- <para>
- Allow function calls to supply parameter names and match them to named
- parameters in the function definition (Pavel Stehule)
- </para>
- </listitem>
-
- <listitem>
- <para>
- Install server-side language PL/pgSQL by default
- </para>
- </listitem>
-
- <listitem>
- <para>
- Major PL/Perl enhancements
- </para>
- </listitem>
- <listitem>
- <para>
- Allow SQL-compliant <link
- linkend="SQL-CREATETRIGGER">per-column triggers</link>
- </para>
- </listitem>
-
- <listitem>
<para>
- Add <link linkend="SQL-CREATETABLE-compatibility">deferrable
- unique constraints</link>
+ Built-in, binary, log-based replication. This advance consists of two features:
+ Hot Standby allows continuous archive standby database servers to accept read-only
+ queries, and Streaming Replication allows continuous archive (<acronym>WAL</>) files
+ to be streamed over a network port to a standby database server.
</para>
</listitem>
<listitem>
<para>
- Have <link linkend="SQL-LISTEN"><command>LISTEN</></link>/<link
- linkend="SQL-NOTIFY"><command>NOTIFY</></link> store events
- in a memory queue, rather than a system table
+ Easier database object permissions management. <link
+ linkend="SQL-GRANT"><command>GRANT</>/<command>REVOKE
+ IN SCHEMA</></link> supports mass permissions changes, and
+ the <link linkend="SQL-ALTERDEFAULTPRIVILEGES"><command>ALTER
+ DEFAULT PRIVILEGES</></link> command controls privileges
+ of all newly-created objects. Large object permissions now
+ support <command>GRANT</>/<command>REVOKE</> as well.
</para>
</listitem>
<listitem>
<para>
- Allow <link linkend="SQL-NOTIFY"><command>NOTIFY</></link>
- to pass an optional string to listeners
+ Broadly enhanced stored procedure support.
+ The <link linkend="SQL-DO"><command>DO</></link> statement permits
+ ad-hoc or anonymous code blocks. Functions can now be called using named
+ parameters. PL/pgSQL is now installed by default, and PL/Perl and PL/Python
+ have been enhanced in several ways.
</para>
</listitem>
<listitem>
<para>
- Change <command>VACUUM FULL</> to rewrite the entire table and
- indexes, rather than moving around single rows to compact space
+ Triggers now support two new features,
+ SQL-compliant <link
+ linkend="SQL-CREATETRIGGER">per-column triggers</link>, and
+ conditional trigger execution.
</para>
</listitem>
<listitem>
<para>
- Add prefix support for the full text search synonym dictionary
+ <link linkend="SQL-CREATETABLE-compatibility">Deferrable
+ unique constraints, now permit mass updates to unique keys.</link>
</para>
</listitem>
<listitem>
<para>
- Use red-black trees for <acronym>GIN</> index creation
+ Exclusion constraints let database designers define uniqueness
+ based on complex criteria, including for non-scalar data such
+ as time periods, ranges and arrays.
</para>
</listitem>
<listitem>
<para>
- Add <link
- linkend="functions-binarystring-other"><function>get_bit()</></link>
- and <function>set_bit()</> functions for <type>bit</>
- strings, mirroring those for <type>bytea</>
+ The <link linkend="SQL-LISTEN"><command>LISTEN</></link>/<link
+ linkend="SQL-NOTIFY"><command>NOTIFY</></link>
+ feature has been overhauled to make it into
+ a high-performance event queuing system. It now stores
+ events in a memory-based queue, and it now allows delivery
+ of a string payload to listeners with each event.
</para>
</listitem>
<listitem>
<para>
- Add the ability for clients to set an <link
- linkend="libpq-connect-application-name">application
- name</link>, which is displayed in
- <structname>pg_stat_activity</>
+ As part of our decade-long effort to eliminate the pain of VACUUM,
+ <command>VACUUM FULL</> is not substantially faster by
+ rewriting the entire table and
+ indexes, rather than moving around single rows to compact space.
</para>
</listitem>
@@ -164,7 +115,7 @@ recovery_connections -> hot_standby
<listitem>
<para>
Add <link linkend="pgupgrade"><filename>/contrib/pg_upgrade</></link>
- to support in-place upgrades
+ to support in-place upgrades from 8.3 or 8.4 to 9.0.
</para>
</listitem>
@@ -208,7 +159,7 @@ recovery_connections -> hot_standby
Remove server variable <varname>regex_flavor</>, which
was defaulted to <link
linkend="posix-syntax-details"><literal>advanced</></link>
- (e.g. Perl-regex compatible) for many years (Tom Lane)
+ (e.g. Perl-regex compatible) for many years. (Tom Lane)
</para>
</listitem>
@@ -307,9 +258,23 @@ recovery_connections -> hot_standby
</para>
<para>
- Administrators still can rename such columns manually. Expression
- index names are also not renamed. WHY ARE EXPRESSION INDEXES
- SIGNIFICANT?
+ Administrators still can rename such columns manually. This change
+ will require an update of the JDBC driver and possibly other drivers
+ so that unique indexes are correctly recognized.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ No longer change function input variable names via
+ <command>REPLACE FUNCTION</command>(Pavel Stehule).
+ </para>
+
+ <para>
+ In order to support names parameter calls, it is
+ no longer possible to change the aliases for input variables
+ in the function declaration in place. You now have to <command>DROP
+ </command> and recreate the function.
</para>
</listitem>
@@ -333,7 +298,8 @@ recovery_connections -> hot_standby
linkend="plpgsql-var-subst"><varname>plpgsql.variable_conflict</></link>,
or by the per-function option <literal>#variable_conflict</>.
The former behavior was to bind to variable names over
- column names.
+ column names, but not consistently. Stored procedures
+ with naming conflicts will probably need to be refactored.
</para>
</listitem>
@@ -357,7 +323,7 @@ recovery_connections -> hot_standby
</para>
<para>
- Variables can be double-quoted to avoid this restriction.
+ Variables can be double-quoted to avoid this restriction.
</para>
</listitem>
</itemizedlist>
@@ -372,9 +338,17 @@ recovery_connections -> hot_standby
<title>Server</title>
<sect4>
- <title>Continuous Archiving</title>
- <itemizedlist>
+ <title>Continuous Archiving and Binary Replication</title>
+
+ <para>
+ PostgreSQL's native standby capability has been expanded both to
+ support read-only queries on standby slaves and to greatly reduce
+ the lag between master and standby servers. For many users, this
+ will be a useful and low-administration form of replication, either
+ for high availability or for horizontal scalability.
+ </para>
+ <itemizedlist>
<listitem>
<para>
Allow continuous archive standby systems to accept read-only queries
@@ -396,6 +370,7 @@ recovery_connections -> hot_standby
</para>
<para>
+ This feature is called Streaming Replication.
Previously <acronym>WAL</> files could be sent to standby systems only
as 16 megabytes files; this allows master changes to be sent to the
standby with very little delay. There are new <filename>postgresql.conf</>
@@ -421,6 +396,12 @@ recovery_connections -> hot_standby
<sect4>
<title>Performance</title>
+
+ <para>
+ Version 9.0 also contains several performance and optimizer enhancements to
+ improve specific uses of PostgreSQL and remedy certain poor-performing cases.
+ </para>
+
<itemizedlist>
<listitem>
@@ -454,27 +435,30 @@ recovery_connections -> hot_standby
<title>Optimizer</title>
<itemizedlist>
+
<listitem>
<para>
- Allow <literal>IS NOT NULL</> restrictions to use indexes (Tom Lane)
+ Remove unnecessary <link linkend="queries-join">outer
+ joins</link> (Robert Haas)
</para>
<para>
- This is particularly useful for finding
- <function>MAX()</>/<function>MIN()</> values in indexes that also
- contain NULLs.
+ Outer joins where the inner side is unique and not referenced in
+ the query are unnecessary and are therefore now removed. This will
+ accelerate many automatically generated queries, such as those created
+ by object-relational mappers.
</para>
</listitem>
<listitem>
<para>
- Remove unnecessary <link linkend="queries-join">outer
- joins</link> (Robert Haas)
+ Allow <literal>IS NOT NULL</> restrictions to use indexes (Tom Lane)
</para>
<para>
- Outer joins where the inner side is unique and not referenced in
- the query are unnecessary and are therefore now removed.
+ This is particularly useful for finding
+ <function>MAX()</>/<function>MIN()</> values in indexes that also
+ contain NULLs.
</para>
</listitem>
@@ -567,7 +551,9 @@ recovery_connections -> hot_standby
<para>
This allows user-override of the number or percentage of distinct
values for a column and optionally its child tables. This value
- is normally computed by <command>ANALYZE</>.
+ is normally computed by <command>ANALYZE</>. Database administrators
+ can use this feature to fix some poor statistics, especially on
+ tables with millions or billions of rows.
</para>
</listitem>
@@ -900,8 +886,10 @@ recovery_connections -> hot_standby
</para>
<para>
- It currently supports tables, views, sequences, and functions, and
- also has per-schema control.
+ This greatly simplifies the assignment of object priveleges in
+ a complex database application. Defaults currently support tables
+ views, sequences, and functions. Defaults may be assigned on a
+ per-schema basis or database-wide.
</para>
</listitem>
@@ -995,8 +983,17 @@ recovery_connections -> hot_standby
TABLE CONSTRAINT ... EXCLUDE</></link> clause. While
uniqueness checks could be specified using this syntax,
the real value of this feature is in using complex
- operators that do not have built-in constraints.
+ operators that do not have built-in constraints.
+ </para>
+
+ <para>
+ The primary use of exclusion constraints is to allow defining
+ non-overlapping uniqueness, such as for time periods, arrays
+ or ranges of values. This supports data integrity at the
+ table level for calendaring, time-management, and scientific
+ applications.
</para>
+
</listitem>
<listitem>
@@ -1026,6 +1023,13 @@ recovery_connections -> hot_standby
linkend="SQL-GRANT"><command>GRANT</>/<command>REVOKE
IN SCHEMA</></link> clause (Petr Jelinek)
</para>
+
+ <para>
+ This simplifies the assignment of object permissions
+ and makes it easier to utilize database roles for application
+ data security.
+ </para>
+
</listitem>
<listitem>
@@ -1055,7 +1059,9 @@ recovery_connections -> hot_standby
</para>
<para>
- This greatly improves performance for these operations.
+ LISTEN/NOTIFY may now be used as a full-featured, high-performance
+ event queue system for PostgreSQL, with transactional support
+ and guaranteed delivery.
</para>
</listitem>
@@ -1114,6 +1120,18 @@ recovery_connections -> hot_standby
<title><link linkend="SQL-EXPLAIN"><command>EXPLAIN</></link></title>
<itemizedlist>
+ <listitem>
+ <para>
+ Allow <command>EXPLAIN</> output in <acronym>XML</>, <acronym>JSON</>,
+ and <acronym>YAML</> formats (Robert Haas, Greg Sabino Mullane)
+ </para>
+
+ <para>
+ The new output formats will support the development of new tools
+ for analysis of EXPLAIN output.
+ </para>
+ </listitem>
+
<listitem>
<para>
Add new <command>EXPLAIN (BUFFERS)</> to report query buffer
@@ -1121,6 +1139,7 @@ recovery_connections -> hot_standby
</para>
<para>
+ This allows better query profiling for individual queries.
log_*_stats log output, e.g. <link
linkend="runtime-config-statistics-monitor">log_statement_stats</link>,
no longer shows this information.
@@ -1134,13 +1153,6 @@ recovery_connections -> hot_standby
</para>
</listitem>
- <listitem>
- <para>
- Allow <command>EXPLAIN</> output in <acronym>XML</>, <acronym>JSON</>,
- and <acronym>YAML</> formats (Robert Haas, Greg Sabino Mullane)
- </para>
- </listitem>
-
<listitem>
<para>
Allow <command>EXPLAIN</> options to be specified inside parentheses
@@ -1169,8 +1181,11 @@ recovery_connections -> hot_standby
</para>
<para>
- The previous method was usually slower and caused index bloat.
+ The previous method was usually slower and caused index bloat.
+ Note that the new method may use more disk space during VACUUM
+ FULL.
</para>
+
</listitem>
<listitem>
@@ -1228,9 +1243,10 @@ recovery_connections -> hot_standby
</para>
<para>
- Red-black trees are self-balanced so allow for faster index
- creation.
+ Red-black trees are self-balanced. This means much faster
+ GIN index creation.
</para>
+
</listitem>
</itemizedlist>
--
GitLab