<!-- doc/src/sgml/release-9.1.sgml -->
+<!-- See header comment in release.sgml about typical markup -->
<sect1 id="release-9-1">
- <title>Release 9.1alpha5</title>
+ <title>Release 9.1</title>
- <sect2>
- <title>Overview</title>
- <para>
- PostgreSQL alpha releases are snapshots of development code.
- They are intended to preview and test upcoming features and to
- provide the possibility for early feedback. They should not be
- used in production installations or active development projects.
- While the PostgreSQL code is continuously subject to a number
- of automated and manual tests, alpha releases might have serious
- bugs. Also features may be changed incompatibly or removed at
- any time during the development cycle.
- </para>
- <para>
- The development cycle of a PostgreSQL major release alternates
- between periods of development and periods of integration work,
- called commit fests, normally one month each. Alpha releases are
- planned to be produced at the end of every commit fest, thus every
- two months. Since the first commit fest starts within a month from
- the beginning of development altogether, early alpha releases are
- not indicative of the likely feature set of the final release.
- </para>
- </sect2>
- <sect2>
- <title>Testing</title>
- <para>
- The primary reason we release alphas is to get users to test new
- features as early as possible. If you are interested in helping
- with organized testing, please see
- <ulink url="http://wiki.postgresql.org/wiki/HowToBetaTest">the
- testing information page</ulink>.
- </para>
- </sect2>
-
-<!--
<note>
<title>Release Date</title>
<simpara>2011-??-??</simpara>
</note>
+ <para>CURRENT AS OF 2011-03-15</para>
+
<sect2>
<title>Overview</title>
<para>
This release of
- <productname>PostgreSQL</> adds ... Major enhancements include:
- (This list duplicates items below, but without authors or details)
+ <productname>PostgreSQL</> adds numerous major features, including:
</para>
+ <para>
+ (summary to be added)
+ </para>
<para>
The above items are explained in more detail in the sections below.
</para>
</sect2>
--->
<sect2>
standard; <link
linkend="guc-escape-string-warning"><varname>escape_string_warning</></link>
has produced warnings about this usage for years. <literal>E''</>
- strings the proper way to embed escapes in strings and is
+ strings are the proper way to embed escapes in strings and are
unaffected by this change.
</para>
</listitem>
</para>
<para>
- For example, disallow composite_name.text and text(composite_name).
- <literal>CAST</> and <literal>::</> are still available for
- casting.
+ For example, disallow
+ <literal><replaceable>composite_value</>.text</literal> and
+ <literal>text(<replaceable>composite_value</>)</literal>.
+ The <literal>CAST</> and <literal>::</> syntaxes are still available
+ for use when a cast of an entire composite value is actually intended.
</para>
</listitem>
<para>
Tighten casting checks for domains based on arrays (Tom Lane)
</para>
-
+
<para>
- **Details?
+ When a domain is based on an array type, it is allowed to <quote>look
+ through</> the domain type to access the array elements, including
+ subscripting the domain value to fetch or assign an element.
+ Assignment to an element of such a domain value, for instance via
+ <literal>UPDATE ... SET domaincol[5] = ...</>, will now result in
+ rechecking the domain type's constraints, whereas before the checks
+ were skipped.
+ </para>
+
+ <para>
+ Also, such a domain type is no longer allowed to match an
+ <type>anyarray</> parameter of a polymorphic function, except by
+ explicitly downcasting it to the base array type.
</para>
</listitem>
<para>
Fix improper checks for before/after triggers (Tom Lane)
</para>
-
+
<para>
- **Tom, I need more details on the impact of this for existing
- installs.
+ Triggers can now be fired in three cases: BEFORE, AFTER, or INSTEAD OF
+ some action. Trigger function authors should verify that their logic
+ behaves sanely in all three cases.
</para>
</listitem>
</para>
<para>
- Previously <literal>RAISE</> in a code block always scoped to
+ Previously <literal>RAISE</> in a code block was always scoped to
an attached exception block, so it was uncatchable at the same
scope.
</para>
<listitem>
<para>
Adjust PL/pgSQL's error line reporting code to be consistent
- with SQL error line reporting (Pavel Stehule)
+ with other PLs (Pavel Stehule)
</para>
-
+
<para>
- Previously error numbering was off by one.
+ Previously, PL/pgSQL would ignore (not count) an empty line at the
+ start of the function body. Since this was inconsistent with all
+ other languages, the special case was removed.
</para>
</listitem>
<para>
Have <link
linkend="monitoring-stats-funcs-table"><function>pg_stat_reset()</></link>
- reset all database-level statistics (Tom Lane)
+ reset all database-level statistics (Tomas Vondra)
</para>
<para>
- Some counters were not being reset.
+ Some <structname>pg_stat_database</> counters were not being reset.
</para>
</listitem>
</sect2>
<sect2>
- <title>Changes, current as of 2011-03-15</title>
+ <title>Changes</title>
<para>
Version 9.1 has ...
</para>
<para>
Previously <literal>FULL OUTER JOIN</literal> could only be
implemented as a merge join, and <literal>LEFT OUTER JOIN</literal>
- and <literal>RIGHT OUTER JOIN</literal> could has only the nullable
+ and <literal>RIGHT OUTER JOIN</literal> could hash only the nullable
side of the join. These changes provide additional query optimization
possibilities.
</para>
<listitem>
<para>
- Allow hash joins for array values (Tom Lane)
+ Support hashing array values (Tom Lane)
</para>
<para>
<para>
Specifically this allows Unix-based <acronym>GSSAPI</> clients
- to <acronym>SSPI</> authenticate to Windows servers.
+ to do <acronym>SSPI</> authentication with Windows servers.
</para>
</listitem>
<para>
Add <link
linkend="monitoring-stats-views-table"><structname>pg_stat_xact_*</></link>
- statistic functions and views (Joel Jacobson)
+ statistics functions and views (Joel Jacobson)
</para>
<para>
- These are like the database-wide statistics counter views but
+ These are like the database-wide statistics counter views, but
reflect counts for only the current transaction.
</para>
</listitem>
<listitem>
<para>
- Add record of last reset in database and background writer-level
+ Add time of last reset in database-level and background writer
statistics views (Tomas Vondra)
</para>
</listitem>
Increase the maximum values for
<link linkend="guc-deadlock-timeout"><varname>deadlock_timeout</varname></link>,
<link linkend="guc-log-min-duration-statement"><varname>log_min_duration_statement</varname></link>, and
- <link linkend="guc-log-autovacuum-min-duration"><varname>log_autovacuum_min_duration</varname></link>.
+ <link linkend="guc-log-autovacuum-min-duration"><varname>log_autovacuum_min_duration</varname></link>
+ (Peter Eisentraut)
</para>
<para>
</para>
<para>
- Cancelations can occur because of dropped tablespaces, lock
+ Cancellations can occur because of dropped tablespaces, lock
timeouts, old snapshots, pinned buffers, and deadlocks.
</para>
</listitem>
<listitem>
<para>
- Add a <literal>conflicts</> count to <link
+ Add a <structfield>conflicts</> count to <link
linkend="monitoring-stats-views-table"><structname>pg_stat_database</></link>
(Magnus Hagander)
</para>
<itemizedlist>
+ <listitem>
+ <para>
+ Add a true <link
+ linkend="xact-serializable"><literal>serializable</></link> isolation
+ level (Kevin Grittner, Dan Ports)
+ </para>
+
+ <para>
+ Previously, asking for serializable isolation guaranteed only that a
+ single MVCC snapshot would be used for the entire transaction, which
+ allowed certain documented anomalies. The old snapshot isolation
+ behavior is still accessible by requesting the <link
+ linkend="xact-repeatable-read"><literal>REPEATABLE READ</></link>
+ isolation level.
+ </para>
+ </listitem>
+
<listitem>
<para>
Allow data-modification commands
</para>
<para>
- This allows <command>INSERT</>/<command>UPDATE</>/<command>DELETE</>
- <literal>RETURNING</> in <literal>WITH</> clauses to pass rows
- to outer queries.
+ These commands can use <literal>RETURNING</> to pass data up to the
+ containing query.
</para>
</listitem>
<listitem>
<para>
Allow <link linkend="queries-with"><literal>WITH</></link>
- clauses to be fed into <command>INSERT</>, <command>UPDATE</>,
- <command>DELETE </> statements (Marko Tiikkaja, Hitoshi Harada)
+ clauses to be attached to <command>INSERT</>, <command>UPDATE</>,
+ <command>DELETE</> statements (Marko Tiikkaja, Hitoshi Harada)
</para>
</listitem>
<listitem>
<para>
- Allow the use of the keyword <link
- linkend="queries-union"><literal>DISTINCT</></link> in
- <literal>UNION</>/<literal>INTERSECT</>/<literal>EXCEPT</>
+ Allow use of the keyword <literal>DISTINCT</> in <link
+ linkend="queries-union"><literal>UNION</>/<literal>INTERSECT</>/<literal>EXCEPT</></link>
clauses (Tom Lane)
</para>
<para>
<literal>DISTINCT</> is the default behavior so use of this
- keyword is redundant.
+ keyword is redundant, but the SQL standard allows it.
</para>
</listitem>
</para>
<para>
- Previously collation could only be set at the database level.
+ Previously collation could only be set at database creation.
Collation can now be set per column, domain, index, or
- expression.
+ expression, via the SQL-standard <literal>COLLATE</> clause.
</para>
</listitem>
</para>
<para>
- This allows data stored in foreign sources to be used like
- native <productname>PostgreSQL</>-stored data.
+ This allows data stored outside the database to be used like
+ native <productname>PostgreSQL</>-stored data. Foreign tables
+ are currently read-only, however.
</para>
</listitem>
<itemizedlist>
- <listitem>
- <para>
- Add a true <link linkend="xact-serializable"><literal>serializable</></link> isolation level (Kevin Grittner, Dan Ports)
- </para>
-
- <para>
- Previously asking for serializable isolation guaranteed only that
- a single MVCC snapshot would be used for the entire transaction, which
- allowed certain documented anomalies.
- The old snapshot isolation level is still accessible by
- requesting the <link linkend="xact-repeatable-read"><literal>REPEATABLE
- READ</></link> isolation level.
- </para>
- </listitem>
-
<listitem>
<para>
Add transaction-level <link linkend="advisory-locks">advisory
<para>
This is similar to the existing session-level advisory locks,
- but are freed at transaction end.
+ but the locks are automatically released at transaction end.
</para>
</listitem>
<listitem>
<para>
- Have <command>EXPLAIN VERBOSE</>
- show the function call expression (Tom Lane)
+ Make <command>EXPLAIN VERBOSE</> show the function call expression
+ in a FunctionScan node (Tom Lane)
</para>
</listitem>
<listitem>
<para>
- Allow CLUSTER to sort the table rather than scanning the index
- when it seems likely to be cheaper (Leonardo Francalanci)
+ Allow <command>CLUSTER</> to sort the table rather than scanning
+ the index when it seems likely to be cheaper (Leonardo Francalanci)
</para>
</listitem>
</para>
<para>
- This allows <acronym>GiST</> indexes to quickly return
- <literal>LIMIT</>-specified closest values.
+ This allows <acronym>GiST</> indexes to quickly return the
+ <replaceable>N</> closest values in a query with <literal>LIMIT</>.
</para>
</listitem>
</para>
<para>
- This allows full <acronym>GIN</> index scans.
+ This allows full <acronym>GIN</> index scans, and fixes various
+ corner cases in which GIN scans would fail.
</para>
</listitem>
<para>
These check whether the input is properly-formed <acronym>XML</>.
- They supersede functionality that was previously available only using
- <filename>contrib/xml2</filename>.
+ They provide functionality that was previously available only in
+ the deprecated <filename>contrib/xml2</filename> module.
</para>
</listitem>
<listitem>
<para>
- Minimise lock levels for <link
+ Minimize lock levels for <link
linkend="SQL-CREATETRIGGER"><command>CREATE TRIGGER</></link>
and many <link linkend="SQL-ALTERTABLE"><command>ALTER
TABLE</></link> and <link linkend="SQL-CREATERULE"><command>CREATE
<listitem>
<para>
Add <link linkend="plpgsql-foreach-array"><command>FOREACH IN
- ARRAY</></link> to <link linkend="plpgsql">PL/pgSQL</link> to
- allow array iteration (Pavel Stehule)
- </para>
-
- <para>
- This is more efficient than previous methods.
- </para>
- </listitem>
-
- <listitem>
- <para>
- Add <link linkend="plpgsql-foreach-array"><command>FOREACH IN
- ARRAY</></link> to <link linkend="plpgsql">PL/pgSQL</link> to
- allow array iteration (Pavel Stehule)
+ ARRAY</></link> to <link linkend="plpgsql">PL/pgSQL</link>
+ (Pavel Stehule)
</para>
<para>
- This is more efficient than previous methods.
+ This is more efficient and readable than previous methods of
+ iterating through the elements of an array value.
</para>
</listitem>
<para>
Allow <command>RAISE</command> without parameters to be caught in
the same places that could catch a <command>RAISE ERROR</command>
- from the same location.
+ from the same location (Piyush Newe)
</para>
<para>
- The new behavior is more consistent.
+ The previous coding threw the error
+ from the block containing the active exception handler.
+ The new behavior is more consistent with other DBMS products.
</para>
</listitem>
</para>
<para>
- **Andrew, I need details on this.
+ PL/Perl functions can now be declared to accept type <type>record</>.
+ The behavior is the same as for any named composite type.
</para>
</listitem>
<listitem>
<para>
- Convert PL/Perl input arguments to Perl arrays (Alexey Klyukin,
+ Convert PL/Perl array arguments to Perl arrays (Alexey Klyukin,
Alex Hunsaker)
</para>
<listitem>
<para>
- Convert PL/Perl row and composite type arguments to Perl hashes
+ Convert PL/Perl composite-type arguments to Perl hashes
(Alexey Klyukin, Alex Hunsaker)
</para>
</para>
<para>
- PL/Python now can return multiple <literal>OUT</> parameters
+ PL/Python can now return multiple <literal>OUT</> parameters
and record sets.
</para>
</listitem>
<listitem>
<para>
- Add validator to PL/Python (Jan Urbanski)
+ Add a validator to PL/Python (Jan Urbanski)
</para>
<para>
- This allows PL/Python functions to be validated at function
+ This allows PL/Python functions to be syntax-checked at function
creation time.
</para>
</listitem>
</para>
</listitem>
- <listitem>
- <para>
- Allow PL/Python to access <literal>SQLSTATE</> exception values
- (Jan Urbanski)
- </para>
-
- <para>
- **Is this the same as the item above?
- </para>
- </listitem>
-
<listitem>
<para>
Add PL/Python explicit subtransactions (Jan Urbanski)
</para>
<para>
- This includes exception support for Python 3. **More?
+ This includes exception support for Python 3. **More detail?
</para>
</listitem>
Mark <link
linkend="APP-CREATELANG"><application>createlang</></link>
and <link linkend="APP-DROPLANG"><application>droplang</></link>
- as deprecated now that they use the extension framework (Tom
+ as deprecated now that they just invoke extension commands (Tom
Lane)
</para>
</listitem>
<para>
Improve <application>pg_ctl</>
start's "wait" (<option>-w</>) mode to handle non-standard
- port numbers, non-standard unix-domain socket locations,
+ port numbers, non-standard Unix-domain socket locations,
permission problems, and stale postmaster lock files (Bruce
Momjian)
</para>
<listitem>
<para>
- Require <acronym>GNU</> <link
- linkend="install-requirements"><application>make</></link>
- 3.80 or newer (Peter Eisentraut)
+ Improved parallel make support (Peter Eisentraut)
+ </para>
+
+ <para>
+ This allows for faster compiles. Also, make <option>-k</>
+ and make <option>-q</> now work properly in a parallel build.
</para>
</listitem>
<listitem>
<para>
- Improved parallel make support (Peter Eisentraut)
+ Require <acronym>GNU</> <link
+ linkend="install-requirements"><application>make</></link>
+ 3.80 or newer (Peter Eisentraut)
</para>
<para>
- This allows for faster compiles. Also, make <option>-k</>
- and make <option>-q</> now work properly. **When was recursive
- make supported?
+ This is necessary because of the parallel-make improvements.
</para>
</listitem>
</para>
<para>
- Foreign tables using this foreign data wrapper will read flat files
- in a matter very similar to <command>COPY</>.
+ Foreign tables using this foreign data wrapper can read flat files
+ in a manner very similar to <command>COPY</>.
</para>
</listitem>
<para>
Add <link
linkend="btree-gist"><filename>contrib/btree_gist</></link>
- support for searching on not equals (Jeff Davis)
+ support for searching on not-equals (Jeff Davis)
</para>
</listitem>
<para>
In
<link linkend="intarray"><filename>contrib/intarray</></link>,
- avoid errors complaining about the presence nulls in cases where no
+ avoid errors complaining about the presence of nulls in cases where no
nulls are actually present (Tom Lane)
</para>
</listitem>
<listitem>
<para>
- In <link linkend="xml2"><filename>contrib/xml2</></link>, remove
- arbitrary limit on the number of parameter=value pairs that
- can be handled by <function>xslt_process()</> (Pavel Stehule)
+ Remove <link linkend="xml2"><filename>contrib/xml2</></link>'s
+ arbitrary limit on the number of
+ <replaceable>parameter</>=<replaceable>value</> pairs that can be
+ handled by <function>xslt_process()</> (Pavel Stehule)
</para>
<para>
- The previous limit was 20.
+ The previous limit was 10.
</para>
</listitem>
linkend="seg"><filename>contrib/seg</></link> columns (Alexander
Korotkov)
</para>
-
- <para>
- **Confirm this does not affect <application>pg_upgrade</>
- </para>
</listitem>
<listitem>
using <link linkend="field-selection"><literal>(compositeval).*
syntax</></link> (Peter Eisentraut)
</para>
-
- <para>
- **Is this syntax new in 9.1?
- </para>
</listitem>
<listitem>
projects / postgresql / blobdiff