-<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.553 2007/11/20 05:23:20 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.554 2007/11/20 17:10:25 momjian Exp $ -->
<!--
Typical markup:
Observe the following incompatibilities:
</para>
- <itemizedlist>
+ <sect3>
+ <title>General</title>
+ <itemizedlist>
- <listitem>
- <para>
- Non-character data types are no longer automatically cast to
- <type>TEXT</> (Peter, Tom)
- </para>
+ <listitem>
+ Non-character data types are no longer automatically cast to
+ <type>TEXT</> (Peter, Tom)
+ </para>
- <para>
- Previously, if a non-character value was supplied to an operator or
- function that requires <type>text</> input, it was automatically
- cast to <type>text</>, for most (though not all) built-in data types.
- This no longer happens: an explicit cast to <type>text</> is now
- required for all non-character-string types. For example, these
- expressions formerly worked:
+ Previously, if a non-character value was supplied to an operator or
+ function that requires <type>text</> input, it was automatically
+ cast to <type>text</>, for most (though not all) built-in data types.
+ This no longer happens: an explicit cast to <type>text</> is now
+ required for all non-character-string types. For example, these
+ expressions formerly worked:
<programlisting>
substr(current_date, 1, 4)
23 LIKE '2%'
</programlisting>
- but will now draw <quote>function does not exist</> and <quote>operator
- does not exist</> errors respectively. Use an explicit cast instead:
+ but will now draw <quote>function does not exist</> and <quote>operator
+ does not exist</> errors respectively. Use an explicit cast instead:
<programlisting>
substr(current_date::text, 1, 4)
23::text LIKE '2%'
</programlisting>
- (Of course, you can use the more verbose <literal>CAST()</> syntax too.)
- The reason for the change is that these automatic casts too often caused
- surprising behavior. An example is that in previous releases, this
- expression was accepted but did not do what was expected:
+ (Of course, you can use the more verbose <literal>CAST()</> syntax too.)
+ The reason for the change is that these automatic casts too often caused
+ surprising behavior. An example is that in previous releases, this
+ expression was accepted but did not do what was expected:
<programlisting>
current_date < 2017-11-17
</programlisting>
- This is actually comparing a date to an integer, which should be
- (and now is) rejected — but in the presence of automatic
- casts both sides were cast to <type>text</> and a textual comparison
- was done, because the <literal>text < text</> operator was able
- to match the expression when no other <literal><</> operator could.
- </para>
+ This is actually comparing a date to an integer, which should be
+ (and now is) rejected — but in the presence of automatic
+ casts both sides were cast to <type>text</> and a textual comparison
+ was done, because the <literal>text < text</> operator was able
+ to match the expression when no other <literal><</> operator could.
+ </para>
- <para>
- Types <type>char(<replaceable>n</>)</type> and
- <type>varchar(<replaceable>n</>)</type> still cast to <type>text</>
- automatically. Also, automatic casting to <type>text</> still works for
- inputs to the concatenation (<literal>||</>) operator, so long as least
- one input is a character-string type.
- </para>
- </listitem>
+ Types <type>char(<replaceable>n</>)</type> and
+ <type>varchar(<replaceable>n</>)</type> still cast to <type>text</>
+ automatically. Also, automatic casting to <type>text</> still works for
+ inputs to the concatenation (<literal>||</>) operator, so long as least
+ one input is a character-string type.
+ </para>
+ </listitem>
- <listitem>
- <para>
- Full text search features from <filename>contrib/tsearch2</> have
- been moved into the core server, with some minor syntax changes
- </para>
+ <listitem>
+ Full text search features from <filename>contrib/tsearch2</> have
+ been moved into the core server, with some minor syntax changes
+ </para>
- <para>
- <filename>contrib/tsearch2</> now contains a compatibility
- interface.
- </para>
- </listitem>
+ <filename>contrib/tsearch2</> now contains a compatibility
+ interface.
+ </para>
+ </listitem>
- <listitem>
- <para>
- Numerous changes in administrative server parameters
- </para>
+ <listitem>
+ <para>
+ <literal>ARRAY(SELECT ...)</literal>, where the <command>SELECT</>
+ returns no rows, now returns an empty array, rather than NULL
+ (Tom)
+ </para>
+ </listitem>
- <para>
- <varname>bgwriter_lru_percent</>,
- <varname>bgwriter_all_percent</>,
- <varname>bgwriter_all_maxpages</>,
- <varname>stats_start_collector</>, and
- <varname>stats_reset_on_server_start</> are removed.
- <varname>redirect_stderr</> is renamed to
- <varname>logging_collector</>.
- <varname>stats_command_string</> is renamed to
- <varname>track_activities</>.
- <varname>stats_block_level</> and <varname>stats_row_level</>
- are merged into <varname>track_counts</>.
- A new boolean configuration parameter, <varname>archive_mode</>,
- controls archiving. Autovacuum's default settings have changed.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ The array type name for a base data type is no longer always the base
+ type's name with an underscore prefix
+ </para>
- <listitem>
- <para>
- Commenting out a parameter in <filename>postgresql.conf</> now
- causes it to revert to its default value (Joachim Wieland)
- </para>
+ <para>
+ The old naming convention is still honored when possible, but
+ application code should no longer depend on it. Instead
+ use the new <literal>pg_type.typarray</literal> column to
+ identify the array data type associated with a given type.
+ </para>
+ </listitem>
- <para>
- Previously, commenting out an entry left the parameter's value unchanged
- until the next server restart.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ <literal>ORDER BY ... USING</> <replaceable>operator</> must now
+ use a less-than or greater-than <replaceable>operator</> that is
+ defined in a btree operator class
+ </para>
- <listitem>
- <para>
- <literal>ARRAY(SELECT ...)</literal>, where the <command>SELECT</>
- returns no rows, now returns an empty array, rather than NULL
- (Tom)
- </para>
- </listitem>
+ <para>
+ This restriction was added to prevent inconsistent results.
+ </para>
+ </listitem>
- <listitem>
- <para>
- <literal>ORDER BY ... USING</> <replaceable>operator</> must now
- use a less-than or greater-than <replaceable>operator</> that is
- defined in a btree operator class
- </para>
+ <listitem>
+ <para>
+ <command>SET LOCAL</command> changes now persist until
+ the end of the outermost transaction, unless rolled back (Tom)
+ </para>
- <para>
- This restriction was added to prevent inconsistent results.
- </para>
- </listitem>
+ <para>
+ Previously <command>SET LOCAL</command>'s effects were lost
+ after subtransaction commit (<command>RELEASE SAVEPOINT</>
+ or exit from a PL/pgSQL exception block).
+ </para>
+ </listitem>
- <listitem>
- <para>
- The array type name for a base data type is no longer always the base
- type's name with an underscore prefix
- </para>
+ <listitem>
+ Commands rejected in transaction blocks are now also rejected in
+ multiple-statement query strings (Tom)
+ </para>
- <para>
- The old naming convention is still honored when possible, but
- application code should no longer depend on it. Instead
- use the new <literal>pg_type.typarray</literal> column to
- identify the array data type associated with a given type.
- </para>
- </listitem>
+ <para>
+ For example, <literal>"BEGIN; DROP DATABASE; COMMIT"</> will now be
+ rejected even if submitted as a single query message.
+ </para>
+ </listitem>
- <listitem>
- <para>
- <command>SET LOCAL</command> changes now persist until
- the end of the outermost transaction, unless rolled back (Tom)
- </para>
+ <listitem>
+ <para>
+ <command>ROLLBACK</> outside a transaction block now
+ issues <literal>NOTICE</> instead of <literal>WARNING</> (Bruce)
+ </para>
+ </listitem>
- <para>
- Previously <command>SET LOCAL</command>'s effects were lost
- after subtransaction commit (<command>RELEASE SAVEPOINT</>
- or exit from a PL/pgSQL exception block).
- </para>
- </listitem>
+ <listitem>
+ <para>
+ Prevent <command>NOTIFY</command>/<command>LISTEN</command>/<command>UNLISTEN</command>
+ from accepting schema-qualified names (Bruce)
+ </para>
- <listitem>
- <para>
- Commands rejected in transaction blocks are now also rejected in
- multiple-statement query strings (Tom)
- </para>
+ <para>
+ Formerly, these commands accepted <literal>schema.relation</> but
+ ignored the schema part, which was confusing.
+ </para>
+ </listitem>
- <para>
- For example, <literal>"BEGIN; DROP DATABASE; COMMIT"</> will now be
- rejected even if submitted as a single query message.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ <command>ALTER SEQUENCE</> no longer affects <function>currval()</>
+ (Tom)
+ </para>
+ </listitem>
- <listitem>
- <para>
- <command>ROLLBACK</> outside a transaction block now
- issues <literal>NOTICE</> instead of <literal>WARNING</> (Bruce)
- </para>
- </listitem>
+ <listitem>
+ <para>
+ Foreign keys now must match indexable conditions for
+ cross-data-type references (Tom)
+ </para>
- <listitem>
- <para>
- Prevent <command>NOTIFY</command>/<command>LISTEN</command>/<command>UNLISTEN</command>
- from accepting schema-qualified names (Bruce)
- </para>
+ <para>
+ This improves semantic consistency and helps avoid
+ performance problems.
+ </para>
+ </listitem>
- <para>
- Formerly, these commands accepted <literal>schema.relation</> but
- ignored the schema part, which was confusing.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ Restrict object size functions to users who have reasonable
+ permissions to view such information (Tom)
+ </para>
- <listitem>
- <para>
- Restrict object size functions to users who have reasonable
- permissions to view such information (Tom)
- </para>
+ <para>
+ For example, <function>pg_database_size()</function> now requires
+ <literal>CONNECT</> permission, which is granted to everyone by
+ default. <function>pg_tablespace_size()</function> requires
+ <literal>CREATE</> permission in the tablespace, or is allowed if
+ the tablespace is the default tablespace for the database.
+ </para>
+ </listitem>
- <para>
- For example, <function>pg_database_size()</function> now requires
- <literal>CONNECT</> permission, which is granted to everyone by
- default. <function>pg_tablespace_size()</function> requires
- <literal>CREATE</> permission in the tablespace, or is allowed if
- the tablespace is the default tablespace for the database.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ Remove the undocumented <literal>!!=</> (not in) operator (Tom)
+ </para>
- <listitem>
- <para>
- Internal hashing functions are now more uniformly-distributed (Tom)
- </para>
+ <para>
+ <literal>NOT IN (SELECT ...)</literal> is the proper way to
+ perform this operation.
+ </para>
+ </listitem>
- <para>
- If application code was computing and storing hash values using
- internal <productname>PostgreSQL</> hashing functions, the hash
- values must be regenerated.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ Internal hashing functions are now more uniformly-distributed (Tom)
+ </para>
- <listitem>
- <para>
- <command>ALTER SEQUENCE</> no longer affects <function>currval()</>
- (Tom)
- </para>
- </listitem>
+ <para>
+ If application code was computing and storing hash values using
+ internal <productname>PostgreSQL</> hashing functions, the hash
+ values must be regenerated.
+ </para>
+ </listitem>
- <listitem>
- <para>
- Foreign keys now must match indexable conditions for
- cross-data-type references (Tom)
- </para>
+ <listitem>
+ C-code conventions for handling variable-length data values
+ have changed (Greg Stark, Tom)
+ </para>
- <para>
- This improves semantic consistency and helps avoid
- performance problems.
- </para>
- </listitem>
+ <para>
+ The new <function>SET_VARSIZE()</> macro <emphasis>must</> be used
+ to set the length of generated <type>varlena</> values. Also, it
+ might be necessary to expand (<quote>de-TOAST</quote>) input values
+ in more cases.
+ </para>
+ </listitem>
- <listitem>
- <para>
- Remove the undocumented <literal>!!=</> (not in) operator (Tom)
- </para>
+ </itemizedlist>
- <para>
- <literal>NOT IN (SELECT ...)</literal> is the proper way to
- perform this operation.
- </para>
- </listitem>
+ </sect3>
- <listitem>
- <para>
- Remove <varname>stats_start_collector</varname> parameter (Tom)
- </para>
+ <sect3>
+ <title>Configuration Parameters</title>
- <para>
- We now always start the collector process, unless <acronym>UDP</>
- socket creation fails.
- </para>
- </listitem>
+ <itemizedlist>
- <listitem>
- <para>
- Remove <varname>stats_reset_on_server_start</varname> parameter (Tom)
- </para>
+ <listitem>
+ Numerous changes in administrative server parameters
+ </para>
- <para>
- This was removed because <function>pg_stat_reset()</function>
- can be used for this purpose.
- </para>
- </listitem>
+ <para>
+ <varname>bgwriter_lru_percent</>,
+ <varname>bgwriter_all_percent</>,
+ <varname>bgwriter_all_maxpages</>,
+ <varname>stats_start_collector</>, and
+ <varname>stats_reset_on_server_start</> are removed.
+ <varname>redirect_stderr</> is renamed to
+ <varname>logging_collector</>.
+ <varname>stats_command_string</> is renamed to
+ <varname>track_activities</>.
+ <varname>stats_block_level</> and <varname>stats_row_level</>
+ are merged into <varname>track_counts</>.
+ A new boolean configuration parameter, <varname>archive_mode</>,
+ controls archiving. Autovacuum's default settings have changed.
+ </para>
+ </listitem>
- <listitem>
- <para>
- C-code conventions for handling variable-length data values
- have changed (Greg Stark, Tom)
- </para>
+ <listitem>
+ <para>
+ Remove <varname>stats_start_collector</varname> parameter (Tom)
+ </para>
- <para>
- The new <function>SET_VARSIZE()</> macro <emphasis>must</> be used
- to set the length of generated <type>varlena</> values. Also, it
- might be necessary to expand (<quote>de-TOAST</quote>) input values
- in more cases.
- </para>
- </listitem>
+ <para>
+ We now always start the collector process, unless <acronym>UDP</>
+ socket creation fails.
+ </para>
+ </listitem>
- </itemizedlist>
+ <listitem>
+ <para>
+ Remove <varname>stats_reset_on_server_start</varname> parameter (Tom)
+ </para>
+ <para>
+ This was removed because <function>pg_stat_reset()</function>
+ can be used for this purpose.
+ </para>
+ </listitem>
- <para>
- The following incompatibilities relate to character encodings:
- </para>
+ <listitem>
+ <para>
+ Commenting out a parameter in <filename>postgresql.conf</> now
+ causes it to revert to its default value (Joachim Wieland)
+ </para>
- <itemizedlist>
+ <para>
+ Previously, commenting out an entry left the parameter's value unchanged
+ until the next server restart.
+ </para>
+ </listitem>
- <listitem>
- <para>
- Add more checks for invalidly-encoded data (Andrew)
- </para>
+ </itemizedlist>
- <para>
- This change plugs some holes that existed in literal backslash
- escape string processing and <command>COPY</command> escape
- processing. Now the de-escaped string is rechecked to see if the
- result created an invalid multi-byte character.
- </para>
- </listitem>
+ </sect3>
- <listitem>
- <para>
- Ensure that <function>chr()</function> cannot create
- invalidly-encoded values (Andrew)
- </para>
- <para>
- In UTF8-encoded databases the argument of <function>chr()</function> is
- now treated as a Unicode code point. In other multi-byte encodings
- <function>chr()</function>'s argument must designate a 7-bit ASCII
- character. Zero is no longer accepted.
- <function>ascii()</function> has been adjusted to match.
- </para>
- </listitem>
+ <sect3>
+ <title>Character Encodings</title>
- <listitem>
- <para>
- Adjust <function>convert()</function> behavior to ensure encoding
- validity (Andrew)
- </para>
+ <itemizedlist>
- <para>
- The two argument form of <function>convert()</function> has been
- removed. The three argument form now takes a <type>bytea</type>
- first argument and returns a <type>bytea</type>. To cover the
- loss of functionality, three new functions have been added:
- </para>
+ <listitem>
+ <para>
+ Add more checks for invalidly-encoded data (Andrew)
+ </para>
- <itemizedlist>
- <listitem>
- <para>
- <function>convert_from(bytea, name)</function> returns
- <type>text</> — converts the first argument from the named
- encoding to the database encoding
- </para>
- </listitem>
+ <para>
+ This change plugs some holes that existed in literal backslash
+ escape string processing and <command>COPY</command> escape
+ processing. Now the de-escaped string is rechecked to see if the
+ result created an invalid multi-byte character.
+ </para>
+ </listitem>
- <listitem>
- <para>
- <function>convert_to(text, name)</function> returns
- <type>bytea</> — converts the first argument from the
- database encoding to the named encoding
- </para>
- </listitem>
+ <listitem>
+ <para>
+ Ensure that <function>chr()</function> cannot create
+ invalidly-encoded values (Andrew)
+ </para>
- <listitem>
- <para>
- <function>length(bytea, name)</function> returns
- <type>integer</> — gives the length of the first
- argument in characters in the named encoding
- </para>
- </listitem>
- </itemizedlist>
- </listitem>
+ <para>
+ In UTF8-encoded databases the argument of <function>chr()</function> is
+ now treated as a Unicode code point. In other multi-byte encodings
+ <function>chr()</function>'s argument must designate a 7-bit ASCII
+ character. Zero is no longer accepted.
+ <function>ascii()</function> has been adjusted to match.
+ </para>
+ </listitem>
- <listitem>
- <para>
- Remove <literal>convert(argument USING conversion_name)</literal>
- (Andrew)
- </para>
+ <listitem>
+ Adjust <function>convert()</function> behavior to ensure encoding
+ validity (Andrew)
+ </para>
- <para>
- Its behavior did not match the SQL standard.
- </para>
- </listitem>
+ <para>
+ The two argument form of <function>convert()</function> has been
+ removed. The three argument form now takes a <type>bytea</type>
+ first argument and returns a <type>bytea</type>. To cover the
+ loss of functionality, three new functions have been added:
+ </para>
- <listitem>
- <para>
- Make JOHAB encoding client-only (Tatsuo)
- </para>
+ <itemizedlist>
+ <listitem>
+ <para>
+ <function>convert_from(bytea, name)</function> returns
+ <type>text</> — converts the first argument from the named
+ encoding to the database encoding
+ </para>
+ </listitem>
- <para>
- JOHAB is not safe as a server-side encoding.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ <function>convert_to(text, name)</function> returns
+ <type>bytea</> — converts the first argument from the
+ database encoding to the named encoding
+ </para>
+ </listitem>
- </itemizedlist>
+ <listitem>
+ <para>
+ <function>length(bytea, name)</function> returns
+ <type>integer</> — gives the length of the first
+ argument in characters in the named encoding
+ </para>
+ </listitem>
+ </itemizedlist>
+ </listitem>
+
+ <listitem>
+ <para>
+ Remove <literal>convert(argument USING conversion_name)</literal>
+ (Andrew)
+ </para>
+
+ <para>
+ Its behavior did not match the SQL standard.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Make JOHAB encoding client-only (Tatsuo)
+ </para>
+
+ <para>
+ JOHAB is not safe as a server-side encoding.
+ </para>
+ </listitem>
+
+ </itemizedlist>
+
+ </sect3>
</sect2>
</para>
</listitem>
+ <listitem>
+ <para>
+ Change server startup log message from <quote>database system is
+ ready</quote> to <quote>database system is ready to accept
+ connections</quote>
+ </para>
+ </listitem>
+
</itemizedlist>
</sect3>
</para>
</listitem>
+ <listitem>
+ <para>
+ Fix pgstats counting of live and dead tuples to recognize that
+ committed and aborted transactions have different effects (Tom)
+ </para>
+ </listitem>
+
</itemizedlist>
</sect3>
</sect3>
<sect3>
- <title>Source Code</title>
+ <title>Server Programming Interface (<acronym>SPI</>)</title>
<itemizedlist>
- <listitem>
- <para>
- Rename macro <literal>DLLIMPORT</> to <literal>PGDLLIMPORT</> to
- avoid conflicting with third party includes (like Tcl) that
- define <literal>DLLIMPORT</> (Magnus)
- </para>
- </listitem>
-
<listitem>
<para>
Allow execution of cursor commands through
</para>
</listitem>
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Build Options</title>
+ <itemizedlist>
+
<listitem>
<para>
Add <application>configure</> <literal>--enable-profiling</>
<listitem>
<para>
- Create <quote>operator families</quote> to improve planning of
- queries involving cross-data-type comparisons (Tom)
+ Fix <acronym>PGXS</> so extensions can be built against PostgreSQL
+ installations whose <application>pg_config</> program does not
+ appear first in the <varname>PATH</> (Tom)
</para>
</listitem>
</para>
</listitem>
+ </itemizedlist>
+
+ </sect3>
+
+ <sect3>
+ <title>Source Code</title>
+ <itemizedlist>
+
<listitem>
<para>
- Update GIN <function>extractQuery()</> API to allow signalling
- that nothing can satisfy the query (Teodor)
+ Rename macro <literal>DLLIMPORT</> to <literal>PGDLLIMPORT</> to
+ avoid conflicting with third party includes (like Tcl) that
+ define <literal>DLLIMPORT</> (Magnus)
</para>
</listitem>
<listitem>
<para>
- Move <literal>NAMEDATALEN</> definition from
- <filename>postgres_ext.h</> to <filename>pg_config_manual.h</>
- (Peter)
+ Create <quote>operator families</quote> to improve planning of
+ queries involving cross-data-type comparisons (Tom)
</para>
</listitem>
<listitem>
<para>
- Change server startup log message from <quote>database system is
- ready</quote> to <quote>database system is ready to accept
- connections</quote>
+ Update GIN <function>extractQuery()</> API to allow signalling
+ that nothing can satisfy the query (Teodor)
</para>
</listitem>
<listitem>
<para>
- Provide <function>strlcpy()</function> and
- <function>strlcat()</function> on all platforms, and replace
- error-prone uses of <function>strncpy()</function>,
- <function>strncat()</function>, etc (Peter)
+ Move <literal>NAMEDATALEN</> definition from
+ <filename>postgres_ext.h</> to <filename>pg_config_manual.h</>
+ (Peter)
</para>
</listitem>
<listitem>
<para>
- Fix pgstats counting of live and dead tuples to recognize that
- committed and aborted transactions have different effects (Tom)
+ Provide <function>strlcpy()</function> and
+ <function>strlcat()</function> on all platforms, and replace
+ error-prone uses of <function>strncpy()</function>,
+ <function>strncat()</function>, etc (Peter)
</para>
</listitem>
<listitem>
<para>
- Have <function>quote_identifier()</function> and
- <application>pg_dump</application> not quote keywords that are
+ <function>quote_identifier()</function> and
+ <application>pg_dump</application> no longer quote keywords that are
unreserved according to the grammar (Tom)
</para>
</listitem>
- <listitem>
- <para>
- Fix <acronym>PGXS</> so extensions can be built against PostgreSQL
- installations whose <application>pg_config</> program does not
- appear first in the <varname>PATH</> (Tom)
- </para>
- </listitem>
-
<listitem>
<para>
Change the on-disk representation of the <type>NUMERIC</type>
projects / postgresql / commitdiff