diff --git a/doc/src/sgml/release-9.0.sgml b/doc/src/sgml/release-9.0.sgml
index 8a6923555aa..fd71d2d6ec5 100644
--- a/doc/src/sgml/release-9.0.sgml
+++ b/doc/src/sgml/release-9.0.sgml
@@ -1,5 +1,4 @@
-
-
+
Release 9.0
@@ -10,4220 +9,2734 @@
- Overview
+ Overview
+
+
+ Based on overwhelming user demand, this release of
+ PostgreSQL adds features that have been requested
+ for years, like easy-to-use replication, a mass permission
+ facility, and anonymous blocks. While past major releases have
+ been quite conservative in their scope, this release shows a
+ bold new desire to provide facilities that every new and existing
+ user of PostgreSQL will embrace. This has all
+ been done with few incompatibilities. The major areas of
+ enhancement are:
+
+
+
+
+
+
+
+
+ Allow continuous archive standby systems to accept read-only queries
+
+
+
+
+
+ Allow continuous archive (WAL) files to be streamed to a
+ standby system
+
+
+
+
+
+ Add the ability to make mass permission changes per
+ schema using the new GRANT/REVOKE
+ IN SCHEMA clause
+
+
+
+
+
+ Add the ability to control large object permissions with
+ GRANT/REVOKE
+
+
+
+
+
+ Implement anonymous functions using the DO statement
+
+
+
+
+
+ Allow function calls to supply parameter names and match them to named
+ parameters in the function definition (Pavel Stehule)
+
+
+
+
+
+ Install server-side language PL/pgSQL by default
+
+
+
+
+
+ Major PL/Perl enhancements
+
+
+
+
+
+ Allow SQL-compliant per-column triggers
+
+
+
+
+
+ Add deferrable
+ unique constraints
+
+
+
+
+
+ Have LISTEN/NOTIFY store events
+ in a memory queue, rather than a system table
+
+
+
+
+
+ Allow NOTIFY
+ to pass an optional string to listeners
+
+
+
+
+
+ Change VACUUM FULL to rewrite the entire table and
+ indexes, rather than moving around single rows to compact space
+
+
+
+
+
+ Add prefix support for the full text search synonym dictionary
+
+
+
+
+
+ Use red-black trees for GIN index creation
+
+
+
+
+
+ Add get_bit()
+ and set_bit() functions for bit
+ strings, mirroring those for bytea
+
+
+
+
+
+ Add the ability for clients to set an application
+ name, which is displayed in
+ pg_stat_activity
+
+
+
+
+
+ Add support for compiling on 64-bit
+ Windows and running in 64-bit
+ mode
+
+
+
+
+
+ The above items are explained in more detail in the sections below.
+
+
+
+
+
+
+
+
+
+ Migration to Version 9.0
+ CURRENT AS OF 2010-04-29
+
+
+ A dump/restore using pg_dump is
+ required for those wishing to migrate data from any previous
+ release.
+
+
+
+ Observe the following incompatibilities:
+
+
+
+ Server Settings
+
+
+
+
+
+ Remove server variable add_missing_from, which was
+ defaulted to off for many years (Tom Lane)
+
+
+
+
+
+ Remove server variable regex_flavor, which
+ was defaulted to advanced
+ (e.g. Perl-regex compatible) for many years (Tom Lane)
+
+
+
+
+
+ It is now necessary to set wal_level to
+ archive to do continuous archiving.
+ (Heikki Linnakangas)
+
+
+
+
+
+
+
+
+ Queries
+
+
+
+
+ When querying a parent table,
+ do not do additional permission checks on child tables
+ returned as part of the query (Peter Eisentraut)
+
- Based on overwhelming user demand, this release of
- PostgreSQL adds features that have been requested
- for years, like easy-to-use replication, a mass permission
- facility, and anonymous blocks. While past major releases have
- been quite conservative in their scope, this release shows a
- bold new desire to provide facilities that every new and existing
- user of PostgreSQL will embrace. This has all
- been done with few incompatibilities. The major areas of
- enhancement are:
+ The SQL standard specifies this behavior.
+
+
+
+
+ Have fractional seconds conversion truncate rather than
+ round when using float-based dates/times (Tom Lane)
+
+
+
+
+
+
+
+
+ String Handling
+
+
+
+
+ Improve standards compliance of SIMILAR TO
+ patterns and SQL-style substring() patterns (Tom Lane)
+
+
+
+ This includes treating ? and {...} as
+ pattern metacharacters, while they were simple literal characters
+ before; that corresponds to new features added in SQL:2008.
+ Also, ^ and $ are now treated as simple
+ literal characters; formerly they were treated as metacharacters,
+ as if the pattern were following POSIX rather than SQL rules.
+ Also, in SQL-standard substring(), use of parentheses
+ for nesting no longer interferes with capturing of a substring.
+ Also, processing of bracket expressions (character classes) is
+ now more standards-compliant.
+
+
+
+
+
+ Reject negative length values in 3-parameter substring()
+ for bit strings, per the SQL standard (Tom Lane)
+
+
+
+
+
+
+
+
+ Object Renaming
+
+
+
+
+ Tighten enforcement of column renaming when a child table inherits
+ the renamed column from an unrelated parent (KaiGai Kohei)
+
+
+
+
+
+ No longer rename index names and index column names when table
+ columns are renamed (Tom Lane)
+
+
+
+ Administrators still can rename such columns manually. Expression
+ index names are also not renamed. WHY ARE EXPRESSION INDEXES
+ SIGNIFICANT?
+
+
+
+
+
+
+
+
+ PL/pgSQL Variables
+
+
+
+
+
+ Have PL/pgSQL throw an error if a variable name conflicts with a
+ column name used in a query (Tom Lane)
+
+
+
+ This behavior can be changed via the server variable plpgsql.variable_conflict,
+ or by the per-function option #variable_conflict.
+ The former behavior was to bind to variable names over
+ column names.
+
+
+
+
+
+ Remove PL/pgSQL's RENAME declaration option (Tom Lane)
+
+
+
+ Instead, use ALIAS,
+ which can now alias any variable, not just dollar sign
+ variables, e.g. $1.
+
+
+
+
+
+ PL/pgSQL no longer allows unquoted variables names that match SQL
+ reserved words (Tom Lane)
+
+
+
+ Variables can be double-quoted to avoid this restriction.
+
+
+
+
+
+
+
+
+ Changes
+
+
+ Server
+
+
+ Continuous Archiving
+
+
+
+
+ Allow continuous archive standby systems to accept read-only queries
+ (Simon Riggs, Heikki Linnakangas)
+
+
+
+ This feature is called Hot Standby. There are new
+ postgresql.conf and recovery.conf
+ settings to enable this feature, as well as extensive
+ documentation.
+
+
+
+
+
+ Allow continuous archive (WAL) files to be streamed to a
+ standby system (Fujii Masao, Heikki Linnakangas)
+
+
+
+ Previously WAL files could be sent to standby systems only
+ as 16 megabytes files; this allows master changes to be sent to the
+ slave with very little delay. There are new postgresql.conf
+ and recovery.conf settings to enable this
+ feature, as well as extensive documentation.
+
+
+
+
+
+ Add pg_last_xlog_receive_location()
+ and pg_last_xlog_replay_location(), which
+ can be used to monitor standby server WAL
+ activity (Simon Riggs, Fujii Masao, Heikki Linnakangas)
+
+
+
+
+
+
+
+
+ Performance
+
+
+
+
+ Improve performance of finding inherited child tables (Tom Lane)
+
+
+
+
+
+ Allow per-tablespace sequential and random page cost variables
+ (seq_page_cost/random_page_cost) via
+ ALTER TABLESPACE
+ ... SET/RESET (Robert Haas)
+
+
+
+
+
+ Improve performance of TRUNCATE when
+ used in the same transaction as table creation (Tom Lane)
+
+
+
+
+
+
+
+
+ Optimizer
+
+
+
+
+ Allow IS NOT NULL restrictions to use indexes (Tom Lane)
+
+
+
+ This is particularly useful for finding
+ MAX()/MIN() values in indexes that also
+ contain NULLs.
+
+
+
+
+
+ Remove unnecessary outer
+ joins (Robert Haas)
+
+
+
+ Outer joins where the inner side is unique and not referenced in
+ the query are unnecessary and are therefore now removed.
+
+
+
+
+
+ Improve optimizer equivalence detection of <> boolean
+ tests (Tom Lane)
+
+
+
+
+
+
+ <link linkend="geqo">GEQO</link>
+
+
+
+
+ Use the same random seed everytime GEQO plans a query (Andres
+ Freund)
+
+
+
+ While the Genetic Query Optimizer (GEQO) still selects
+ random plans, it now selects the same random plans for
+ identical queries. You can modify geqo_seed to randomize
+ the starting value of the random plan generator.
+
+
+
+
+
+ Improve GEQO plan selection (Tom Lane).
+
+
+
+ This avoids the rare error, "failed to make a valid plan".
+
+
+
+
+
+
+
+
+ Optimizer Statistics
+
+
+
+
+ Improve ANALYZE
+ to support inheritance-tree statistics (Tom Lane)
+
+
+
+ This is particularly useful for partitioned tables.
+
+
+
+
+
+ Improve autovacuum
+ detection of when re-analyze is necessary (Tom Lane)
+
+
+
+
+
+ Improve optimizer statistics for greater/less-than comparisons
+ (Tom Lane)
+
+
+
+ When looking up optimizer statistics for greater/less-than comparisons,
+ if the comparison value is in the first or last histogram bucket,
+ use an index to generate the actual statistics. This is particularly
+ useful for columns that are always increasing, and hence often have
+ inaccurate statistics.
+
+
+
+
+
+ Allow setting of distinct statistics using ALTER TABLE
+ (Robert Haas)
+
+
+
+ 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 ANALYZE.
+
+
+
+
+
+
+
+
+ Authentication
+
+
+
+
+ Add support for RADIUS (Remote
+ Authentication Dial In User Service) authentication
+ (Magnus Hagander)
+
+
+
+
+
+
+ Allow LDAP
+ (Lightweight Directory Access Protocol) authentication
+ to operate in "search/bind" mode (Robert Fleming, Magnus)
+
+
+
+ This allows the user to be looked up first, then the system uses
+ the DN (Distinguished Name) returned for that user.
+
+
+
+
+
+ Add samehost
+ and samenet designations to
+ pg_hba.conf (Stef Walter)
+
+
+
+ These match the server's IP address and network address
+ respectively.
+
+
+
+
+
+
+
+
+ Monitoring
+
+
+
+
+ Add the ability for clients to set an application
+ name, which is displayed in
+ pg_stat_activity (Dave Page)
+
+
+
+
+
+ Add an SQL state option (%e) to log_line_prefix
+ (Guillaume Smet)
+
+
+
+
+
+ Write to the Windows event log in UTF16 encoding
+ (Itagaki Takahiro)
+
+
+
+
+
+
+
+
+ Statistics Counters
+
+
+
+
+ Add pg_stat_reset_shared('bgwriter')
+ to reset the cluster-wide shared statistics of the
+ bgwriter (Greg Smith)
+
+
+
+
+
+ Add pg_stat_reset_single_table_counters()
+ and pg_stat_reset_single_function_counters()
+ to allow the reseting of statistics counters for individual
+ tables and indexes (Magnus Hagander)
+
+
+
+
+
+
+
+
+ Server Settings
+
+
+
+
+ Allow setting of configuration variables based on database/role
+ combinations (Alvaro Herrera)
+
+
+
+ Previously only per-database and per-role setting were possible,
+ not combinations. All role and database settings are now stored
+ in the new pg_db_role_setting system table. A new
+ psql \drds command shows these settings.
+ Backwards-compatible system views do not show this information.
+
+
+
+
+
+ Add boolean variable bonjour, which
+ controls whether a Bonjour-enabled binary advertises
+ itself via Bonjour (Tom Lane)
+
+
+
+ The default is off, meaning it does not advertise.
+
+
+
+
+
+ Add boolean variable enable_material, which
+ controls the use of materialize nodes in the optimizer
+ (Robert Haas)
+
+
+
+ The default is on.
+
+
+
+
+
+ Log changed parameter values when postgresql.conf is
+ reloaded (Peter Eisentraut)
+
+
+
+
+
+ Add proper permissions for custom variables (Tom Lane)
+
+
+
+ Custom variables can now only be created by super-users,
+ but can be modified by ordinary users if variable
+ permissions allow it. This makes custom variables
+ appropriate for security settings. Previously, any user
+ could create or modify custom variables.
+
+
+
+
+
+
+
+
+
+
+ Queries
+
+
+
+
+ Do SELECT
+ FOR UPDATE/SHARE processing after
+ applying LIMIT, so the number of rows returned
+ is always predictable (Tom Lane)
+
+
+
+ Previously, concurrent transactions could potentially cause
+ SELECT to return fewer rows than specified by
+ LIMIT. FOR UPDATE can still affect
+ ORDER BY ordering, but this can be corrected by using
+ FOR UPDATE in a subquery.
+
+
+
+
+
+ Allow mixing of traditional and SQL-standard LIMIT/OFFSET
+ syntax in the same query (Tom Lane)
+
+
+
+
+
+ Increase the supported frame options in window functions (Hitoshi
+ Harada)
+
+
+
+ This allows frames (RANGE or ROWS) to start
+ with CURRENT ROW, and to use the ROWS n
+ PRECEDING/FOLLOWING clause.
+
+
+
+
+
+ Have SELECT and CREATE TABLE AS return
+ row counts to the client
+ (Boszormenyi Zoltan)
+
+
+
+ psql does not display these counts.
+
+
+
+
+
+
+ Unicode Strings
+
+
+
+
+ Add Unicode surrogate pair (dual 16-bit) support to
+ U&
+ strings and identifiers (Peter Eisentraut)
+
+
+
+
+
+ Allow Unicode escapes in E'...'
+ strings (Marko Kreen)
+
+
+
+
+
+
+
+
+
+
+ Object Manipulation
+
+
+
+
+ Speed up CREATE
+ DATABASE by deferring flushes to disk (Andres
+ Freund, Greg Stark)
+
+
+
+
+
+ Allow comments only on
+ columns of tables, views, and composite types, not other
+ objects like indexes and TOAST tables (Tom Lane)
+
+
+
+
+
+ Allow the creation of enumerate types with
+ no labels (Bruce Momjian)
+
+
+
+ This is useful for supporting binary upgrades.
+
+
+
+
+
+ Have columns defined with storage type MAIN remain on
+ the main heap page unless it cannot fit (Kevin Grittner)
+
+
+
+ Previously MAIN values were forced to TOAST
+ tables until the row size was one-quarter of the page size.
+
+
+
+
+
+
+ <command>ALTER</>
+
+
+
+
+ Add ALTER
+ DEFAULT PRIVILEGES command to control privileges
+ of all newly-created objects (Petr Jelinek)
+
+
+
+ It currently supports tables, views, sequences, and functions, and
+ also has per-schema control.
+
+
+
+
+
+ Implement IF EXISTS for DROP COLUMN and
+ DROP CONSTRAINT (Andres Freund)
+
+
+
+
+
+ Allow ALTER TABLE commands which rewrite tables to skip
+ WAL logging (Itagaki Takahiro)
+
+
+
+ Such operations either complete fully or are rolled back, so
+ WAL archiving can be skipped, unless running in continuous
+ archiving mode.
+
+
+
+
+
+
+
+
+ <link linkend="SQL-CREATETABLE"><command>CREATE TABLE</></link>
+
+
+
+
+ Add support for copying COMMENTS and STORAGE
+ to the CREATE TABLE ... LIKE INCLUDING command (Itagaki
+ Takahiro)
+
+
+
+
+
+ Add support for copying all attributes to the CREATE
+ TABLE LIKE INCLUDING command (Itagaki Takahiro)
+
+
+
+
+
+ Add the SQL-standard CREATE TABLE ... OF type command
+ (Peter Eisentraut)
+
+
+
+ This allows the creation of a table to match an existing composite
+ type. Additional constraints and defaults can be specified in the
+ command.
+
+
+
+
+
+
+
+
+ Constraints
+
+
+
+
+ Add deferrable
+ unique constraints (Dean Rasheed)
+
+
+
+ This allows UPDATE tab SET col = col + 1 to work on
+ columns that have a unique indexes or are marked as primary keys,
+ but DEFERRABLE INITIALLY DEFERRED must be used to mark
+ the constraint as deferred.
+
+
+
+
+
+ Generalize uniqueness constraints by allowing arbitrary operator
+ comparisons, not just equality (Jeff Davis)
+
+
+
+ This is enabled with the CREATE
+ TABLE CONSTRAINT ... EXCLUDE 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.
+
+
+
+
+
+ Improve the constraint violation error message to report the values
+ causing the failure (Itagaki Takahiro)
+
+
+
+ For example, a uniqueness constraint violation now reports Key
+ (x)=(2) already exists.
+
+
+
+
+
+
+
+
+ Object Permissions
+
+
+
+
+ Add the ability to make mass permission changes per
+ schema using the new GRANT/REVOKE
+ IN SCHEMA clause (Petr Jelinek)
+
+
+
+
+
+ Add the ability to control large object permissions with
+ GRANT/REVOKE (KaiGai Kohei)
+
+
+
+
+
+
+
+
+
+
+ Utility Operations
+
+
+
+
+
+ Have LISTEN/NOTIFY store events
+ in a memory queue, rather than a system table (Joachim
+ Wieland)
+
+
+
+ This greatly improves performance for these operations.
+
+
+
+
+
+ Allow NOTIFY
+ to pass an optional string to listeners (Joachim Wieland)
+
+
+
+
+
+ Allow CLUSTER
+ on all system tables (Tom Lane)
+
+
+
+ Global system tables still cannot be clustered.
+
+
+
+
+
+
+ <link linkend="SQL-COPY"><command>COPY</></link>
+
+
+
+
+ Allow * as a parameter in FORCE QUOTE for
+ COPY CSV (Itagaki Takahiro)
+
+
+
+ This forces quotes for all CSV output columns.
+
+
+
+
+
+ Add new COPY syntax that allows parameters to be
+ specified in parentheses (Robert Haas, Emmanuel Cecchet)
+
+
+
+ This allows greater flexibility for future COPY options.
+ The old syntax is still supported.
+
+
+
+
+
+
+
+
+ <link linkend="SQL-EXPLAIN"><command>EXPLAIN</></link>
+
+
+
+
+ Add new EXPLAIN (BUFFERS) to report query buffer
+ activity (Itagaki Takahiro)
+
+
+
+ log_*_stats log output, e.g. log_statement_stats,
+ no longer shows this information.
+
+
+
+
+
+ Add hash usage information to EXPLAIN output (Robert
+ Haas)
+
+
+
+
+
+ Allow EXPLAIN output in XML, JSON,
+ and YAML formats (Robert Haas, Greg Sabino Mullane)
+
+
+
+
+
+ Allow EXPLAIN options to be specified inside parentheses
+ (Robert Haas)
+
+
+
+ This allows for the expansion of EXPLAIN options. The
+ old syntax is still supported.
+
+
+
+
+
+
+
+
+ <link linkend="SQL-VACUUM"><command>VACUUM</></link>
+
+
+
+
+ Change VACUUM FULL to rewrite the entire table and
+ indexes, rather than moving around single rows to compact space
+ (Itagaki Takahiro, Tom Lane)
+
+
+
+ The previous method was usually slower and caused index bloat.
+
+
+
+
+
+ Add new VACUUM syntax that allows parameters to be
+ specified in parentheses (Itagaki Takahiro)
+
+
+
+ This allows greater flexibility for future VACUUM
+ options. The old syntax is still supported.
+
+
+
+
+
+
+
+
+ Indexes
+
+
+
+
+ Allow an index to be auto-named by not supplying an index name to
+ CREATE INDEX (Tom Lane)
+
+
+
+
+
+ Allow REINDEX
+ on system indexes (Tom Lane)
+
+
+
+ WAS THIS POSSIBLE ON ANY SYSTEM TABLE BEFORE? NON-HARDWIRED ONES?
+
+
+
+
+
+ Add point_ops opclass for GiST (Teodor Sigaev)
+
+
+
+ DETAILS?
+
+
+
+
+
+ Use red-black trees for GIN index creation
+ (Teodor Sigaev)
+
+
+
+ Red-black trees are self-balanced so allow for faster index
+ creation.
+
+
+
+
+
+
+
+
+
+
+ Data Types
+
+
+
+
+ Allow hex values to be specified in bytea strings
+ (Peter Eisentraut)
+
+
+
+ The variable bytea_output controls
+ if hex (default) or octal escapes are used for bytea
+ output. (SWITCH DEFAULT FOR BETA? PETER) Libpq's
+ PQescapeByteaConn() now uses the hex format
+ for PostgreSQL 9.0 servers.
+
+
+
+
+
+ Allow extra_float_digits
+ to be increased to 3 (Tom Lane)
+
+
+
+ The previous maximum extra_float_digits was 2.
+
+
+
+
+
+
+ <link linkend="textsearch">Full Text Search</link>
+
+
+
+
+ Add prefix support for the full text search synonym dictionary
+ (Teodor Sigaev)
+
+
+
+
+
+ Add full text search filtering dictionaries (Teodor Sigaev)
+
+
+
+ Filtering dictionaries allow tokens to be modified and passed to
+ subsequent dictionaries.
+
+
+
+
+
+ Allow underscores in full text email addresses (Teodor Sigaev)
+
+
+
+
+
+ Use more standards-compliant rules for URL
+ parsing (Tom Lane)
+
+
+
+
+
+
+
+
+
+
+ Functions
+
+
+
+
+ Allow case-insensitive regular expression
+ matching with UTF-8 server encodings.
+
+
+
+ Previously, only ASCII characters and single-byte
+ encodings worked properly. Other multi-byte, non-UTF-8
+ encodings are still broken for case-insensitive regular expression
+ matching.
+
+
+
+
+
+ Allow function calls to supply parameter names and match them to named
+ parameters in the function definition (Pavel Stehule)
+
+
+
+ For example, if a function is defined to take parameters a
+ and b, it can be called with func(7 AS a, 12
+ AS b) or func(12 AS b, 7 AS a).
+
+
+
+
+
+ Add support for to_char()
+ scientific notation output ('EEEE')
+ (Pavel Stehule, Brendan Jurd)
+
+
+
+
+
+ Have to_char() honor 'FM'
+ (fill mode) in 'Y', 'YY', and
+ 'YYY' specifications (Bruce Momjian, Tom Lane)
+
+
+
+ It was already honored by 'YYYY'.
+
+
+
+
+
+ Fix to_char() to output the proper localized
+ numeric and monetary characters on Windows
+ (Hiroshi Inoue, Itagaki Takahir, Bruce Momjian)
+
+
+
+
+
+ Correct calculations of "overlap"
+ and "contains" operations over polygons (Teodor Sigaev)
+
+
+
+
+
+
+ Aggregates
+
+
+
+
+ Allow aggregate functions to use ORDER BY (Andrew
+ Gierth)
+
+
+
+ For example, this is now supported, array_agg(a ORDER BY
+ b). This is useful for aggregates where the order of values is
+ significant.
+
+
+
+
+
+ Add the string_agg()
+ aggregate function which aggregates values into a single
+ string (Pavel Stehule)
+
+
+
+ An optional second argument allows specification of a delimiter.
+
+
+
+
+
+ Aggregate functions that are called with DISTINCT are
+ now passed NULL values if the aggregate transition function is
+ not marked as STRICT (Andrew Gierth)
+
+
+
+ For example, agg(DISTINCT x) might pass NULL x
+ values to agg().
+
+
+
+
+
+
+
+
+ Bit Strings
+
+
+
+
+ Add get_bit()
+ and set_bit() functions for bit
+ strings, mirroring those for bytea (Leonardo
+ F)
+
+
+
+
+
+ Implement OVERLAY()
+ (replace) for bit strings and bytea
+ (Leonardo F)
+
+
+
+
+
+
+
+
+ Object Information Functions
+
+
+
+
+ Add pg_table_size()
+ and pg_indexes_size() to provide a more
+ user-friendly interface to the pg_relation_size()
+ function (Bernd Helmle)
+
+
+
+
+
+ Add has_sequence_privilege()
+ for sequence permission checking (Abhijit Menon-Sen)
+
+
+
+
+
+ Have information
+ schema properly display date type octet lengths
+ (Peter Eisentraut)
+
+
+
+ The reported length is now the maximum octet length; previously,
+ a huge value was reported.
+
+
+
+
+
+ Speed up information schema privilege views (Joachim Wieland)
+
+
+
+
+
+
+
+
+ Function and Trigger Creation
+
+
+
+
+ Implement anonymous functions using the DO statement (Petr
+ Jelinek, Joshua Tolley, Hannu Valtonen)
+
+
+
+ This allows execution of server-side code without the need to create
+ a new function and execute it.
+
+
+
+
+
+ Allow SQL-compliant per-column triggers
+ (Itagaki Takahiro)
+
+
+
+ Such triggers are fired only if the specified columns are affected
+ by the query, e.g. in UPDATE's SET list.
+ information_schema now also shows this information.
+
+
+
+
+
+ Add WHERE clause to CREATE TRIGGER
+ to allow control over whether a trigger is fired (Takahiro
+ Itagaki)
+
+
+
+ While a check can be performed inside the trigger, doing it in an
+ external WHERE clause has performance benefits.
+
+
+
+
+
+
+
+
+
+
+ Server-Side Languages
+
+
+
+
+
+ Add the OR REPLACE clause to CREATE LANGUAGE
+ (Tom Lane)
+
+
+
+ This is helpful to optionally install a language if it does not
+ already exist, and is particularly helpful now that PL/pgSQL is
+ installed by default.
+
+
+
+
+
+
+ <link linkend="plpgsql">PL/PgSQL</link> Server-Side
+ Language
-
-
-
-
- Allow continuous archive standby systems to accept read-only queries
-
-
-
-
-
- Allow continuous archive (WAL) files to be streamed to a
- standby system
-
-
-
-
-
- Add the ability to make mass permission changes per
- schema using the new GRANT/REVOKE
- IN SCHEMA clause
-
-
-
-
-
- Add the ability to control large object permissions with
- GRANT/REVOKE
-
-
-
-
-
- Implement anonymous functions using the DO statement
-
-
-
-
-
- Allow function calls to supply parameter names and match them to named
- parameters in the function definition (Pavel Stehule)
-
-
-
-
-
- Install server-side language PL/pgSQL by default
-
-
-
-
-
- Major PL/Perl enhancements
-
-
-
-
-
- Allow SQL-compliant per-column triggers
-
-
-
-
-
- Add deferrable
- unique constraints
-
-
-
-
-
- Have LISTEN/NOTIFY store events
- in a memory queue, rather than a system table
-
-
-
-
-
- Allow NOTIFY
- to pass an optional string to listeners
-
-
-
-
-
- Change VACUUM FULL to rewrite the entire table and
- indexes, rather than moving around single rows to compact space
-
-
-
-
-
- Add prefix support for the full text search synonym dictionary
-
-
-
-
-
- Use red-black trees for GIN index creation
-
-
-
-
-
- Add get_bit()
- and set_bit() functions for bit
- strings, mirroring those for bytea
-
-
-
-
-
- Add the ability for clients to set an application
- name, which is displayed in
- pg_stat_activity
-
-
-
-
-
- Add support for compiling on 64-bit
- Windows and running in 64-bit
- mode
-
-
-
-
-
- The above items are explained in more detail in the sections below.
-
-
-
-
-
-
-
-
-
- Migration to Version 9.0
- CURRENT AS OF 2010-04-29
-
-
- A dump/restore using pg_dump is
- required for those wishing to migrate data from any previous
- release.
-
-
-
- Observe the following incompatibilities:
-
-
-
- Server Settings
-
-
-
-
-
- Remove server variable add_missing_from, which was
- defaulted to off for many years (Tom Lane)
-
-
-
-
-
- Remove server variable regex_flavor, which
- was defaulted to advanced
- (e.g. Perl-regex compatible) for many years (Tom Lane)
-
-
-
-
-
- It is now necessary to set wal_level to
- archive to do continuous archiving.
- (Heikki Linnakangas)
-
-
-
-
-
-
-
-
- Queries
-
-
-
-
- When querying a parent table,
- do not do additional permission checks on child tables
- returned as part of the query (Peter Eisentraut)
-
-
-
- The SQL standard specifies this behavior.
-
-
-
-
-
- Have fractional seconds conversion truncate rather than
- round when using float-based dates/times (Tom Lane)
-
-
-
-
-
-
-
-
- String Handling
-
-
-
-
- Improve standards compliance of SIMILAR TO
- patterns and SQL-style substring() patterns (Tom Lane)
-
-
-
- This includes treating ? and {...} as
- pattern metacharacters, while they were simple literal characters
- before; that corresponds to new features added in SQL:2008.
- Also, ^ and $ are now treated as simple
- literal characters; formerly they were treated as metacharacters,
- as if the pattern were following POSIX rather than SQL rules.
- Also, in SQL-standard substring(), use of parentheses
- for nesting no longer interferes with capturing of a substring.
- Also, processing of bracket expressions (character classes) is
- now more standards-compliant.
-
-
-
-
-
- Reject negative length values in 3-parameter substring()
- for bit strings, per the SQL standard (Tom Lane)
-
-
-
-
-
-
-
-
- Object Renaming
-
-
-
-
- Tighten enforcement of column renaming when a child table inherits
- the renamed column from an unrelated parent (KaiGai Kohei)
-
-
-
-
-
- No longer rename index names and index column names when table
- columns are renamed (Tom Lane)
-
-
-
- Administrators still can rename such columns manually. Expression
- index names are also not renamed. WHY ARE EXPRESSION INDEXES
- SIGNIFICANT?
-
-
-
-
-
-
-
-
- PL/pgSQL Variables
-
-
-
-
-
- Have PL/pgSQL throw an error if a variable name conflicts with a
- column name used in a query (Tom Lane)
-
-
-
- This behavior can be changed via the server variable plpgsql.variable_conflict,
- or by the per-function option #variable_conflict.
- The former behavior was to bind to variable names over
- column names.
-
-
-
-
-
- Remove PL/pgSQL's RENAME declaration option (Tom Lane)
-
-
-
- Instead, use ALIAS,
- which can now alias any variable, not just dollar sign
- variables, e.g. $1.
-
-
-
-
-
- PL/pgSQL no longer allows unquoted variables names that match SQL
- reserved words (Tom Lane)
-
-
-
- Variables can be double-quoted to avoid this restriction.
-
-
-
-
-
-
-
-
- Changes
-
-
- Server
-
-
- Continuous Archiving
-
-
-
-
- Allow continuous archive standby systems to accept read-only queries
- (Simon Riggs, Heikki Linnakangas)
-
-
-
- This feature is called Hot Standby. There are new
- postgresql.conf and recovery.conf
- settings to enable this feature, as well as extensive
- documentation.
-
-
-
-
-
- Allow continuous archive (WAL) files to be streamed to a
- standby system (Fujii Masao, Heikki Linnakangas)
-
-
-
- Previously WAL files could be sent to standby systems only
- as 16 megabytes files; this allows master changes to be sent to the
- slave with very little delay. There are new postgresql.conf
- and recovery.conf settings to enable this
- feature, as well as extensive documentation.
-
-
-
-
-
- Add pg_last_xlog_receive_location()
- and pg_last_xlog_replay_location(), which
- can be used to monitor standby server WAL
- activity (Simon Riggs, Fujii Masao, Heikki Linnakangas)
-
-
-
-
-
-
-
-
- Performance
-
-
-
-
- Improve performance of finding inherited child tables (Tom Lane)
-
-
-
-
-
- Allow per-tablespace sequential and random page cost variables
- (seq_page_cost/random_page_cost) via
- ALTER TABLESPACE
- ... SET/RESET (Robert Haas)
-
-
-
-
-
- Improve performance of TRUNCATE when
- used in the same transaction as table creation (Tom Lane)
-
-
-
-
-
-
-
-
- Optimizer
-
-
-
-
- Allow IS NOT NULL restrictions to use indexes (Tom Lane)
-
-
-
- This is particularly useful for finding
- MAX()/MIN() values in indexes that also
- contain NULLs.
-
-
-
-
-
- Remove unnecessary outer
- joins (Robert Haas)
-
-
-
- Outer joins where the inner side is unique and not referenced in
- the query are unnecessary and are therefore now removed.
-
-
-
-
-
- Improve optimizer equivalence detection of <> boolean
- tests (Tom Lane)
-
-
-
-
-
-
- <link linkend="geqo">GEQO</link>
-
-
-
-
- Use the same random seed everytime GEQO plans a query (Andres
- Freund)
-
-
-
- While the Genetic Query Optimizer (GEQO) still selects
- random plans, it now selects the same random plans for
- identical queries. You can modify geqo_seed to randomize
- the starting value of the random plan generator.
-
-
-
-
-
- Improve GEQO plan selection (Tom Lane).
-
-
-
- This avoids the rare error, "failed to make a valid plan".
-
-
-
-
-
-
-
-
- Optimizer Statistics
-
-
-
-
- Improve ANALYZE
- to support inheritance-tree statistics (Tom Lane)
-
-
-
- This is particularly useful for partitioned tables.
-
-
-
-
-
- Improve autovacuum
- detection of when re-analyze is necessary (Tom Lane)
-
-
-
-
-
- Improve optimizer statistics for greater/less-than comparisons
- (Tom Lane)
-
-
-
- When looking up optimizer statistics for greater/less-than comparisons,
- if the comparison value is in the first or last histogram bucket,
- use an index to generate the actual statistics. This is particularly
- useful for columns that are always increasing, and hence often have
- inaccurate statistics.
-
-
-
-
-
- Allow setting of distinct statistics using ALTER TABLE
- (Robert Haas)
-
-
-
- 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 ANALYZE.
-
-
-
-
-
-
-
-
- Authentication
-
-
-
-
- Add support for RADIUS (Remote
- Authentication Dial In User Service) authentication
- (Magnus Hagander)
-
-
-
-
-
-
- Allow LDAP
- (Lightweight Directory Access Protocol) authentication
- to operate in "search/bind" mode (Robert Fleming, Magnus)
-
-
-
- This allows the user to be looked up first, then the system uses
- the DN (Distinguished Name) returned for that user.
-
-
-
-
-
- Add samehost
- and samenet designations to
- pg_hba.conf (Stef Walter)
-
-
-
- These match the server's IP address and network address
- respectively.
-
-
-
-
-
-
-
-
- Monitoring
-
-
-
-
- Add the ability for clients to set an application
- name, which is displayed in
- pg_stat_activity (Dave Page)
-
-
-
-
-
- Add an SQL state option (%e) to log_line_prefix
- (Guillaume Smet)
-
-
-
-
-
- Write to the Windows event log in UTF16 encoding
- (Itagaki Takahiro)
-
-
-
-
-
-
-
-
- Statistics Counters
-
-
-
-
- Add pg_stat_reset_shared('bgwriter')
- to reset the cluster-wide shared statistics of the
- bgwriter (Greg Smith)
-
-
-
-
-
- Add pg_stat_reset_single_table_counters()
- and pg_stat_reset_single_function_counters()
- to allow the reseting of statistics counters for individual
- tables and indexes (Magnus Hagander)
-
-
-
-
-
-
-
-
- Server Settings
-
-
-
-
- Allow setting of configuration variables based on database/role
- combinations (Alvaro Herrera)
-
-
-
- Previously only per-database and per-role setting were possible,
- not combinations. All role and database settings are now stored
- in the new pg_db_role_setting system table. A new
- psql \drds command shows these settings.
- Backwards-compatible system views do not show this information.
-
-
-
-
-
- Add boolean variable bonjour, which
- controls whether a Bonjour-enabled binary advertises
- itself via Bonjour (Tom Lane)
-
-
-
- The default is off, meaning it does not advertise.
-
-
-
-
-
- Add boolean variable enable_material, which
- controls the use of materialize nodes in the optimizer
- (Robert Haas)
-
-
-
- The default is on.
-
-
-
-
-
- Log changed parameter values when postgresql.conf is
- reloaded (Peter Eisentraut)
-
-
-
-
-
- Add proper permissions for custom variables (Tom Lane)
-
-
-
- Custom variables can now only be created by super-users,
- but can be modified by ordinary users if variable
- permissions allow it. This makes custom variables
- appropriate for security settings. Previously, any user
- could create or modify custom variables.
-
-
-
-
-
-
-
-
-
-
- Queries
-
-
-
-
- Do SELECT
- FOR UPDATE/SHARE processing after
- applying LIMIT, so the number of rows returned
- is always predictable (Tom Lane)
-
-
-
- Previously, concurrent transactions could potentially cause
- SELECT to return fewer rows than specified by
- LIMIT. FOR UPDATE can still affect
- ORDER BY ordering, but this can be corrected by using
- FOR UPDATE in a subquery.
-
-
-
-
-
- Allow mixing of traditional and SQL-standard LIMIT/OFFSET
- syntax in the same query (Tom Lane)
-
-
-
-
-
- Increase the supported frame options in window functions (Hitoshi
- Harada)
-
-
-
- This allows frames (RANGE or ROWS) to start
- with CURRENT ROW, and to use the ROWS n
- PRECEDING/FOLLOWING clause.
-
-
-
-
-
- Have SELECT and CREATE TABLE AS return
- row counts to the client
- (Boszormenyi Zoltan)
-
-
-
- psql does not display these counts.
-
-
-
-
-
-
- Unicode Strings
-
-
-
-
- Add Unicode surrogate pair (dual 16-bit) support to
- U&
- strings and identifiers (Peter Eisentraut)
-
-
-
-
-
- Allow Unicode escapes in E'...'
- strings (Marko Kreen)
-
-
-
-
-
-
-
-
-
-
- Object Manipulation
-
-
-
-
- Speed up CREATE
- DATABASE by deferring flushes to disk (Andres
- Freund, Greg Stark)
-
-
-
-
-
- Allow comments only on
- columns of tables, views, and composite types, not other
- objects like indexes and TOAST tables (Tom Lane)
-
-
-
-
-
- Allow the creation of enumerate types with
- no labels (Bruce Momjian)
-
-
-
- This is useful for supporting binary upgrades.
-
-
-
-
-
- Have columns defined with storage type MAIN remain on
- the main heap page unless it cannot fit (Kevin Grittner)
-
-
-
- Previously MAIN values were forced to TOAST
- tables until the row size was one-quarter of the page size.
-
-
-
-
-
-
- <command>ALTER</>
-
-
-
-
- Add ALTER
- DEFAULT PRIVILEGES command to control privileges
- of all newly-created objects (Petr Jelinek)
-
-
-
- It currently supports tables, views, sequences, and functions, and
- also has per-schema control.
-
-
-
-
-
- Implement IF EXISTS for DROP COLUMN and
- DROP CONSTRAINT (Andres Freund)
-
-
-
-
-
- Allow ALTER TABLE commands which rewrite tables to skip
- WAL logging (Itagaki Takahiro)
-
-
-
- Such operations either complete fully or are rolled back, so
- WAL archiving can be skipped, unless running in continuous
- archiving mode.
-
-
-
-
-
-
-
-
- <link linkend="SQL-CREATETABLE"><command>CREATE TABLE</></link>
-
-
-
-
- Add support for copying COMMENTS and STORAGE
- to the CREATE TABLE ... LIKE INCLUDING command (Itagaki
- Takahiro)
-
-
-
-
-
- Add support for copying all attributes to the CREATE
- TABLE LIKE INCLUDING command (Itagaki Takahiro)
-
-
-
-
-
- Add the SQL-standard CREATE TABLE ... OF type command
- (Peter Eisentraut)
-
-
-
- This allows the creation of a table to match an existing composite
- type. Additional constraints and defaults can be specified in the
- command.
-
-
-
-
-
-
-
-
- Constraints
-
-
-
-
- Add deferrable
- unique constraints (Dean Rasheed)
-
-
-
- This allows UPDATE tab SET col = col + 1 to work on
- columns that have a unique indexes or are marked as primary keys,
- but DEFERRABLE INITIALLY DEFERRED must be used to mark
- the constraint as deferred.
-
-
-
-
-
- Generalize uniqueness constraints by allowing arbitrary operator
- comparisons, not just equality (Jeff Davis)
-
-
-
- This is enabled with the CREATE
- TABLE CONSTRAINT ... EXCLUDE 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.
-
-
-
-
-
- Improve the constraint violation error message to report the values
- causing the failure (Itagaki Takahiro)
-
-
-
- For example, a uniqueness constraint violation now reports Key
- (x)=(2) already exists.
-
-
-
-
-
-
-
-
- Object Permissions
-
-
-
-
- Add the ability to make mass permission changes per
- schema using the new GRANT/REVOKE
- IN SCHEMA clause (Petr Jelinek)
-
-
-
-
-
- Add the ability to control large object permissions with
- GRANT/REVOKE (KaiGai Kohei)
-
-
-
-
-
-
-
-
-
-
- Utility Operations
-
-
-
-
-
- Have LISTEN/NOTIFY store events
- in a memory queue, rather than a system table (Joachim
- Wieland)
-
-
-
- This greatly improves performance for these operations.
-
-
-
-
-
- Allow NOTIFY
- to pass an optional string to listeners (Joachim Wieland)
-
-
-
-
-
- Allow CLUSTER
- on all system tables (Tom Lane)
-
-
-
- Global system tables still cannot be clustered.
-
-
-
-
-
-
- <link linkend="SQL-COPY"><command>COPY</></link>
-
-
-
-
- Allow * as a parameter in FORCE QUOTE for
- COPY CSV (Itagaki Takahiro)
-
-
-
- This forces quotes for all CSV output columns.
-
-
-
-
-
- Add new COPY syntax that allows parameters to be
- specified in parentheses (Robert Haas, Emmanuel Cecchet)
-
-
-
- This allows greater flexibility for future COPY options.
- The old syntax is still supported.
-
-
-
-
-
-
-
-
- <link linkend="SQL-EXPLAIN"><command>EXPLAIN</></link>
-
-
-
-
- Add new EXPLAIN (BUFFERS) to report query buffer
- activity (Itagaki Takahiro)
-
-
-
- log_*_stats log output, e.g. log_statement_stats,
- no longer shows this information.
-
-
-
-
-
- Add hash usage information to EXPLAIN output (Robert
- Haas)
-
-
-
-
-
- Allow EXPLAIN output in XML, JSON,
- and YAML formats (Robert Haas, Greg Sabino Mullane)
-
-
-
-
-
- Allow EXPLAIN options to be specified inside parentheses
- (Robert Haas)
-
-
-
- This allows for the expansion of EXPLAIN options. The
- old syntax is still supported.
-
-
-
-
-
-
-
-
- <link linkend="SQL-VACUUM"><command>VACUUM</></link>
-
-
-
-
- Change VACUUM FULL to rewrite the entire table and
- indexes, rather than moving around single rows to compact space
- (Itagaki Takahiro, Tom Lane)
-
-
-
- The previous method was usually slower and caused index bloat.
-
-
-
-
-
- Add new VACUUM syntax that allows parameters to be
- specified in parentheses (Itagaki Takahiro)
-
-
-
- This allows greater flexibility for future VACUUM
- options. The old syntax is still supported.
-
-
-
-
-
-
-
-
- Indexes
-
-
-
-
- Allow an index to be auto-named by not supplying an index name to
- CREATE INDEX (Tom Lane)
-
-
-
-
-
- Allow REINDEX
- on system indexes (Tom Lane)
-
-
-
- WAS THIS POSSIBLE ON ANY SYSTEM TABLE BEFORE? NON-HARDWIRED ONES?
-
-
-
-
-
- Add point_ops opclass for GiST (Teodor Sigaev)
-
-
-
- DETAILS?
-
-
-
-
-
- Use red-black trees for GIN index creation
- (Teodor Sigaev)
-
-
-
- Red-black trees are self-balanced so allow for faster index
- creation.
-
-
-
-
-
-
-
-
-
-
- Data Types
-
-
-
-
- Allow hex values to be specified in bytea strings
- (Peter Eisentraut)
-
-
-
- The variable bytea_output controls
- if hex (default) or octal escapes are used for bytea
- output. (SWITCH DEFAULT FOR BETA? PETER) Libpq's
- PQescapeByteaConn() now uses the hex format
- for PostgreSQL 9.0 servers.
-
-
-
-
-
- Allow extra_float_digits
- to be increased to 3 (Tom Lane)
-
-
-
- The previous maximum extra_float_digits was 2.
-
-
-
-
-
-
- <link linkend="textsearch">Full Text Search</link>
-
-
-
-
- Add prefix support for the full text search synonym dictionary
- (Teodor Sigaev)
-
-
-
-
-
- Add full text search filtering dictionaries (Teodor Sigaev)
-
-
-
- Filtering dictionaries allow tokens to be modified and passed to
- subsequent dictionaries.
-
-
-
-
-
- Allow underscores in full text email addresses (Teodor Sigaev)
-
-
-
-
-
- Use more standards-compliant rules for URL
- parsing (Tom Lane)
-
-
-
-
-
-
-
-
-
-
- Functions
-
-
-
-
- Allow case-insensitive regular expression
- matching with UTF-8 server encodings.
-
-
-
- Previously, only ASCII characters and single-byte
- encodings worked properly. Other multi-byte, non-UTF-8
- encodings are still broken for case-insensitive regular expression
- matching.
-
-
-
-
-
- Allow function calls to supply parameter names and match them to named
- parameters in the function definition (Pavel Stehule)
-
-
-
- For example, if a function is defined to take parameters a
- and b, it can be called with func(7 AS a, 12
- AS b) or func(12 AS b, 7 AS a).
-
-
-
-
-
- Add support for to_char()
- scientific notation output ('EEEE')
- (Pavel Stehule, Brendan Jurd)
-
-
-
-
-
- Have to_char() honor 'FM'
- (fill mode) in 'Y', 'YY', and
- 'YYY' specifications (Bruce Momjian, Tom Lane)
-
-
-
- It was already honored by 'YYYY'.
-
-
-
-
-
- Fix to_char() to output the proper localized
- numeric and monetary characters on Windows
- (Hiroshi Inoue, Itagaki Takahir, Bruce Momjian)
-
-
-
-
-
- Correct calculations of "overlap"
- and "contains" operations over polygons (Teodor Sigaev)
-
-
-
-
-
-
- Aggregates
-
-
-
-
- Allow aggregate functions to use ORDER BY (Andrew
- Gierth)
-
-
-
- For example, this is now supported, array_agg(a ORDER BY
- b). This is useful for aggregates where the order of values is
- significant.
-
-
-
-
-
- Add the string_agg()
- aggregate function which aggregates values into a single
- string (Pavel Stehule)
-
-
-
- An optional second argument allows specification of a delimiter.
-
-
-
-
-
- Aggregate functions that are called with DISTINCT are
- now passed NULL values if the aggregate transition function is
- not marked as STRICT (Andrew Gierth)
-
-
-
- For example, agg(DISTINCT x) might pass NULL x
- values to agg().
-
-
-
-
-
-
-
-
- Bit Strings
-
-
-
-
- Add get_bit()
- and set_bit() functions for bit
- strings, mirroring those for bytea (Leonardo
- F)
-
-
-
-
-
- Implement OVERLAY()
- (replace) for bit strings and bytea
- (Leonardo F)
-
-
-
-
-
-
-
-
- Object Information Functions
-
-
-
-
- Add pg_table_size()
- and pg_indexes_size() to provide a more
- user-friendly interface to the pg_relation_size()
- function (Bernd Helmle)
-
-
-
-
-
- Add has_sequence_privilege()
- for sequence permission checking (Abhijit Menon-Sen)
-
-
-
-
-
- Have information
- schema properly display date type octet lengths
- (Peter Eisentraut)
-
-
-
- The reported length is now the maximum octet length; previously,
- a huge value was reported.
-
-
-
-
-
- Speed up information schema privilege views (Joachim Wieland)
-
-
-
-
-
-
-
-
- Function and Trigger Creation
-
-
-
-
- Implement anonymous functions using the DO statement (Petr
- Jelinek, Joshua Tolley, Hannu Valtonen)
-
-
-
- This allows execution of server-side code without the need to create
- a new function and execute it.
-
-
-
-
-
- Allow SQL-compliant per-column triggers
- (Itagaki Takahiro)
-
-
-
- Such triggers are fired only if the specified columns are affected
- by the query, e.g. in UPDATE's SET list.
- information_schema now also shows this information.
-
-
-
-
-
- Add WHERE clause to CREATE TRIGGER
- to allow control over whether a trigger is fired (Takahiro
- Itagaki)
-
-
-
- While a check can be performed inside the trigger, doing it in an
- external WHERE clause has performance benefits.
-
-
-
-
-
-
-
-
-
-
- Server-Side Languages
-
-
-
-
-
- Add the OR REPLACE clause to CREATE LANGUAGE
- (Tom Lane)
-
-
-
- This is helpful to optionally install a language if it does not
- already exist, and is particularly helpful now that PL/pgSQL is
- installed by default.
-
-
-
-
-
-
- <link linkend="plpgsql">PL/PgSQL</link> Server-Side
- Language
-
-
-
-
-
- Install server-side language PL/pgSQL by default (Bruce Momjian)
-
-
-
-
-
- Allow PL/pgSQL to handle row types with dropped columns (Pavel Stehule)
-
-
-
-
-
- Allow IN parameters to be assigned values within
- PL/pgSQL functions (Steve Prentice)
-
-
-
-
-
- Improve error location reporting in PL/pgSQL (Tom Lane)
-
-
-
-
-
- Have PL/pgSQL use the main lexer, rather than a custom version (Tom Lane)
-
-
-
-
-
-
-
-
- <link linkend="plpgsql-cursors">PL/pgSQL Cursors</link>
-
-
-
-
- Add count and ALL options to MOVE
- FORWARD/BACKWARD in PL/pgSQL (Pavel Stehule)
-
-
-
-
-
- Allow PL/pgSQL's WHERE CURRENT OF to use a cursor
- variable (Tom Lane)
-
-
-
-
-
- Add PL/pgSQL's OPEN cursor FOR EXECUTE to use parameters
- (Pavel Stehule, Itagaki Takahiro)
-
-
-
- This is accomplished with a new USING clause.
-
-
-
-
-
-
-
-
- <link linkend="plperl">PL/Perl</link> Server-Side Language
-
-
-
-
- Add new PL/Perl functions: quote_literal(),
- quote_nullable(), quote_ident(),
- encode_bytea(), decode_bytea(),
- looks_like_number(),
- encode_array_literal(),
- encode_array_constructor() (Tim Bunce)
-
-
-
-
-
- Add server variable plperl.on_init to
- specify a PL/Perl Perl initialization function (Tim
- Bunce)
-
-
-
- plperl.on_plperl_init
- and plperl.on_plperlu_init are also available
- for trusted/untrusted-specific initialization.
-
-
-
-
-
- Improve error context support in PL/Perl (Alexey Klyukin)
-
-
-
-
-
- Support END blocks in PL/Perl (Tim Bunce)
-
-
-
- END blocks do not currently allow database access.
-
-
-
-
-
- Allow use strict in PL/Perl (Tim Bunce)
-
-
-
- This can be enabled with the server variable plperl.use_strict.
-
-
-
-
-
- Allow require in PL/Perl (Tim Bunce)
-
-
-
- This basically tests to see if the module is loaded, and if not,
- generates an error.
-
-
-
-
-
- Allow use feature in PL/Perl if Perl version 5.10 or
- later is used (Tim Bunce)
-
-
-
-
-
- Verify that PL/Perl return values are valid in the server encoding
- (Andrew Dunstan)
-
-
-
-
-
- Improve PL/Perl code structure (Tim Bunce)
-
-
-
-
-
- PL/Perl subroutines are now given names (Tim Bunce)
-
-
-
- This is for the use of profiling and code coverage tools. DIDN'T
- THEY HAVE NAMES BEFORE?
-
-
-
-
-
- PL/Perl no longer allows Safe version 2.20 because
- it is unsafe (Tim Bunce)
-
-
-
-
-
-
-
-
- <link linkend="plpython">PL/Python</link> Server-Side Language
-
-
-
-
- Add Unicode support in PL/Python (Peter Eisentraut)
-
-
-
- Strings are automatically converted from/to the server encoding as
- necessary.
-
-
-
-
-
- Improve bytea support in PL/Python (Caleb Welton)
-
-
-
- Bytea values passed into PL/Python now are represented as
- binary, rather than the Postgres bytea text format. Null
- bytes are now also output properly from PL/Python. Boolean
- and numeric value passing in PL/Python was also improved.
-
-
-
-
-
- Add array parameter/return
- support to PL/Python (Peter Eisentraut)
-
-
-
-
-
- Improve mapping of domains to Python base types in PL/Python (Peter Eisentraut)
-
-
-
-
-
- Add Python 3 support to PL/Python (Peter Eisentraut)
-
-
-
- The new server-side language is called plpython3u.
-
-
-
-
-
- Improve error location and exception reporting in PL/Python (Peter Eisentraut)
-
-
-
-
-
-
-
-
-
-
- Client Applications
-
-
-
-
- Add vacuumdb
-
-
-
-
-
-
- <link linkend="APP-PSQL"><application>psql</></link>
-
-
-
-
- Properly escape psql variables and
- identifiers (Pavel Stehule, Robert Haas)
-
-
-
- For example, :'var' will be escaped as a literal string, and
- :"var" will be escaped as an SQL identifier.
-
-
-
-
-
- Ignore leading UTF-8-encoded Unicode byte-order marker in
- psql (Itagaki Takahiro)
-
-
-
- This is enabled when the client encoding is UTF-8.
-
-
-
-
-
- Fix psql --file - to properly honor
-
-
-
-
- Prevent overwriting of psql's command-line history
- if two psql sessions are run simultaneously (Tom Lane)
-
-
-
-
-
- Improve psql's tab completion support (Itagaki
- Takahiro)
-
-
-
-
-
-
- <application>psql</> Display
-
-
-
-
- Allow psql to use fancy Unicode line-drawing
- characters via \pset linestyle unicode (Roger Leigh)
-
-
-
-
-
- Improve display of wrapped columns in psql (Roger
- Leigh)
-
-
-
- The previous format is available by using \pset linestyle
- old-ascii.
-
-
-
-
-
-
-
-
- <application>psql</> <link
- linkend="APP-PSQL-meta-commands"><command>\d</></link>
- Commands
-
-
-
-
- Have \d show child tables that inherit from the specified
- parent (Damien Clochard)
-
-
-
- \d shows only the number of child tables, while
- \d+ shows the names of all child tables.
-
-
-
-
-
- Show definition of indexes in \d index_name (Khee Chin)
-
-
-
- The definition is useful for expression indexes.
-
-
-
-
-
- In psql, show the view definition only with \d+,
- not with \d (Peter Eisentraut)
-
-
-
-
-
-
-
-
-
- <link linkend="APP-PGDUMP"><application>pg_dump</></link>
-
-
-
-
- Have pg_dump/pg_restore
-
-
-
-
-
- Fix pg_dump to properly dump large objects if
- standard_conforming_strings is enabled (Tom Lane)
-
-
-
- Large objects dumps now use hex format for output. (SWITCH DEFAULT
- FOR BETA? TOM)
-
-
-
-
-
- Allow pg_dump to dump comments attached to columns
- of composite types (Taro Minowa (Higepon))
-
-
-
-
-
- Have pg_dump
-
-
- These were already present in custom output mode.
-
-
-
-
-
-
-
-
- <link
- linkend="app-pg-ctl"><application>pg_ctl</></link>
-
-
-
-
- Allow pg_ctl to be safely used to start the
- postmaster at boot-time (Tom Lane)
-
-
-
- Previously the pg_ctl process could have been mistakenly
- identified as a running postmaster based on a stale
- postmaster lock file.
-
-
-
-
-
- Give pg_ctl the ability to initialize the database
- (like initdb) (Zdenek Kotala)
-
-
-
-
-
-
-
-
-
-
-
- <application>Development Tools</>
-
-
- <link linkend="libpq"><application>libpq</></link>
-
-
-
-
-
- Add new libpq functions
- PQconnectdbParams()
- and PQconnectStartParams() (Guillaume
- Lelarge)
-
-
-
- These functions are similar to PQconnectdb() and
- PQconnectStart() except they allow a null-terminated
- array of connection options, rather than requiring all options to
- be sent in a single string.
-
-
-
-
-
- Add libpq functions PQescapeLiteral()
- and PQescapeIdentifier() (Robert Haas)
-
-
-
- These functions return appropriately quoted and escaped literal
- strings and identifiers. The caller is not required to pre-allocate
- the string result, as is required by PQescapeStringConn().
-
-
-
-
-
- Add checking for a per-user service file (.pg_service.conf),
- which is checked before the site-wide service file
- (Peter Eisentraut)
-
-
-
- The file .pg_service.conf is assumed to be in the
- user's home directory.
-
-
-
-
-
- Properly report an error if the specified libpq service
- cannot be found (Peter Eisentraut)
-
-
-
-
-
- Issue a warning if the .pgpass-retrieved
- password fails (Bruce Momjian)
-
-
-
-
-
-
-
-
- <link linkend="ecpg"><application>ecpg</></link>
-
-
-
-
- Add SQLDA
- (SQL Descriptor Area) support to ecpg
- (Boszormenyi Zoltan)
-
-
-
-
-
- Add the DESCRIBE
- [OUTPUT] statement to ecpg
- (Boszormenyi Zoltan)
-
-
-
-
-
- Add an ecpg function to return the
- current transaction status (Bernd Helmle)
-
-
-
-
-
- Add the string data type in ecpg
- Informix-compatibility mode (Zoltan Boszormenyi)
-
-
-
-
-
- Allow ecpg to use new and old
- variable names without restriction (Michael Meskes)
-
-
-
-
-
- Allow ecpg to use variable names in
- free()(Michael Meskes)
-
-
-
-
-
- Have ecpg return zero for non-SQL3 data types
- (Michael Meskes))
-
-
-
- Previously it returned the negative of the data type oid.
-
-
-
-
-
-
- <application>ecpg</> Cursors
-
-
-
-
- Add ecpg out-of-scope cursor support in native mode
- (Boszormenyi Zoltan)
-
-
-
- This allows DECLARE to use variables that are not in
- scope when OPEN is called. This facility already existed
- in ecpg Informix-compatibility mode.
-
-
-
-
-
- Allow dynamic ecpg cursor names (Boszormenyi Zoltan)
-
-
-
-
-
- Allow ecpg to use noise words FROM and
- IN in FETCH and MOVE (Zoltan
- Boszormenyi)
-
-
-
-
-
-
-
-
-
-
-
-
- Build Options
-
-
-
-
- Enable client thread safety by default (Bruce Momjian)
-
-
-
- Thread-safe builds can be disabled with configure
-
-
-
-
-
- Add a compile-time option to allow the Linux out-of-memory killer
- to kill backends (Alex Hunsaker, Tom Lane)
-
-
-
- Now that /proc/self/oom_adj allows disabling
- of the Linux out-of-memory (OOM)
- killer for the postmaster and its children, the new
- compile-time option -DLINUX_OOM_ADJ=0
- allows the killer to be enabled for postmaster
- children. pg_config shows if this flag
- was used during compilation.
-
-
-
-
-
- Use DocBook XSL stylesheets for man page
- building (Peter Eisentraut)
-
-
-
-
-
-
- Makefiles
-
-
-
-
- New Makefile targets world,
- install-world, and installcheck-world
- (Andrew Dunstan)
-
-
-
- These are similar to the existing all, install,
- and installcheck targets, but they build HTML
- documentation, build and test /contrib, and test
- server-side languages and ecpg.
-
-
-
-
-
- Add data and documentation location control to PGXS Makefiles
- (Mark Cave-Ayland)
-
-
-
-
-
- Restructure the HTML documentation build
- Makefile rules (Peter Eisentraut)
-
-
-
-
-
-
-
-
- New Requirements
-
-
-
-
- Require Autoconf 2.63 for building from source (Peter Eisentraut)
-
-
-
-
-
- Require Flex 2.5.31 or later to build from source
- (Tom Lane)
-
-
-
-
-
- Require Perl version 5.8 or greater to build the server
- from a CVS copy (John Naylor, Andrew)
-
-
-
-
-
-
-
-
- Windows
-
-
-
-
- Add support for compiling on 64-bit
- Windows and running in 64-bit
- mode (Tsutomu Yamada, Magnus)
-
-
-
- This allows for large shared memory sizes on Windows.
-
-
-
-
-
- Allow server builds using Visual Studio
- 2008 (Magnus Hagander)
-
-
-
-
-
- Allow multi-processor compilation using Microsoft Visual
- C (Magnus Hagander)
-
-
-
-
-
-
-
-
-
-
- Source Code
-
-
-
-
- Distribute documentation in a proper directory tree, rather than
- as tar archive files inside the main distribution tarball (Peter Eisentraut)
-
-
-
- For example, the HTML documentation is now in
- doc/src/sgml/html; the manual pages are packaged
- similarly.
-
-
-
-
-
- Enable the server lexer to be reentrant (Tom Lane)
-
-
-
- This was needed for use of the lexer by PL/pgSQL.
-
-
-
-
-
- Improve speed of memory allocation (Tom Lane, Greg Stark)
-
-
-
-
-
- Add system columns to better document the use of indexes for constraint
- enforcement (Tom Lane)
-
-
-
-
-
- Allow multiple actions to be communicated using the same operating
- system signal (Fujii Masao)
-
-
-
- This allows improved backend communication as new features are
- added.
-
-
-
-
-
- Improve source code test coverage, including /contrib, PL/Python,
- and PL/Perl (Peter Eisentraut, Andrew Dustan)
-
-
-
-
-
- Remove the use of flat files for system table bootstrapping
- (Tom Lane, Alvaro Herrera)
-
-
-
- This also improves performance when using millions of users and
- databases.
-
-
-
-
-
- Improve the ability to translate psql strings
- (Peter Eisentraut)
-
-
-
-
-
- Reduce the length of some file names so file paths are less than
- 100 characters (Tom Lane)
-
-
-
- Some decompression programs have problems with long file names.
-
-
-
-
-
- Tighten input requirements for int2 vector input (Caleb
- Welton)
-
-
-
-
-
- Add a new ERRCODE_INVALID_PASSWORD
- SQLSTATE error code (Bruce Momjian)
-
-
-
-
-
- Properly remove the few remaining personal source code copyright
- entries (Bruce Momjian)
-
-
-
- The personal copyright notices were insignificant but the community
- occasionally had to answer questions about them.
-
-
-
-
-
-
- Feature Support
-
-
-
-
- Use a more modern API for Bonjour (Tom Lane)
-
-
-
- Bonjour now requires OS X 10.3 or later.
-
-
-
-
-
- Add processor test-and-test lock support for the SuperH
- architecture (Nobuhiro Iwamatsu)
-
-
-
-
-
- Allow non-GCC compilers to use inline functions if
- they support them (Kurt Harriman)
-
-
-
-
-
- Remove support for platforms that don't have a working 64-bit
- integer data types (Tom Lane)
-
-
-
- It is believed all supported platforms have working 64-bit integer
- data types.
-
-
-
-
-
-
-
-
-
- Server Programming
-
-
-
-
- Allow use of C++ functions in backend code (Kurt
- Harriman, Peter Eisentraut)
-
-
-
- This removes keyword conflicts that previously made C++
- usage difficult in backend code. extern "C" { } might still
- be necessary.
-
-
-
-
-
- Add AggCheckCallContext()
- for use in detecting if a C function is
- being called as an aggregate (Hitoshi Harada)
-
-
-
-
-
- Require fastgetattr() and heap_getattr()
- backend macros to use a non-NULL fourth argument (Robert Haas)
- KEEP?
-
-
-
-
-
-
-
-
- Server Hooks
-
-
-
-
- Add parser hooks to access column and parameter references in
- queries (Tom Lane)
-
-
-
-
-
- Add a hook so loadable modules can control utility commands (Itagaki
- Takahiro)
-
-
-
-
-
- Allow the calling of parser hooks from SPI and cached
- plans (Tom Lane)
-
-
-
-
-
-
-
-
- Binary Upgrade Support
-
-
-
-
- Add support for preservation of all relfilenodes,
- for use during binary upgrades (Bruce Momjian)
-
-
-
-
-
- Add support for binary upgrades to preserve pg_type
- and pg_enum oids (Bruce Momjian)
-
-
-
- This is needed to allow binary upgrades of user-defined composite
- types, arrays, and enums (enumerated types).
-
-
-
-
-
- Move tablespace data directories into their own
- PostgreSQL version-specific subdirectory (Bruce Momjian)
-
-
-
- This simplifies binary upgrades.
-
-
-
-
-
-
-
-
-
-
- Contrib
-
-
-
-
- Add multi-threaded option (
-
-
- This allows multiple CPUs to be used for pgbench tests.
-
-
-
-
-
- Add \shell and \setshell meta
- commands to /contrib/pgbench
- (Michael Paquier)
-
-
-
-
-
- New features for /contrib/dict_xsyn
- (Sergey Karpov)
-
-
-
- The new options are matchorig, matchsynonyms,
- and keepsynonyms.
-
-
-
-
-
- Add full text dictionary /contrib/unaccent
- (Teodor Sigaev)
-
-
-
- This filter dictionary removes accents from tokens.
-
-
-
-
-
- Add dblink_get_notify()
- to /contrib/dblink (Marcus Kempe)
-
-
-
- This allows async notifications in dblink.
-
-
-
-
-
- Greatly increase /contrib/hstore's
- length limit and add btree and hash abilities so GROUP
- BY and DISTINCT operations are possible
- (Andrew Gierth)
-
-
-
- New functions and operators were also added.
-
-
-
-
-
- Add /contrib/passwordcheck
- which can check the strength of assigned passwords (Laurenz
- Albe)
-
-
-
- The source code of this module should be modified to implement
- site-specific password policies.
-
-
-
-
-
- Add query text to /contrib/auto_explain
- output (Andrew Dunstan)
-
-
-
-
-
- Add buffer access counters to /contrib/pg_stat_statements
- (Itagaki Takahiro)
-
-
-
-
-
- Update /contrib/start-scripts/linux
- to use /proc/self/oom_adj to disable the
- Linux
- out-of-memory (OOM) killer (Alex
- Hunsaker, Tom Lane)
-
-
-
-
-
-
-
-
-
-
-
- Release 9.0alpha4
-
- Overview
-
- 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.
-
-
- 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.
-
-
- The release notes below highlight user visible changes and new
- features. There are normally numerous bug fixes and performance
- improvements in every new snapshot of PostgreSQL, and it would be
- too bulky to attempt to list them all. Note that many bug fixes are
- also backported to stable releases of PostgreSQL, and you should be
- using those if you are looking for bug-fix-only upgrades for your
- current installations.
-
-
- The release notes are cumulative over all alpha releases. Items
- that are new in the latest alpha release
- are emphasized.
-
-
-
- Migration
-
- To upgrade from any release to an alpha release or from an alpha
- release to any other release will most likely require a
- dump/restore upgrade procedure. It may happen that this is not
- necessary in particular cases, but that is not verified beforehand.
- (The server will warn you in any case when a dump/restore is
- necessary if you attempt to use it with an old data directory.)
- Note, however, that the dump/restore upgrade procedure is expected
- to work for alpha releases, and problems in this area should be
- reported.
-
-
-
- Testing
-
- 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
- the
- testing information page.
+
+
+ Install server-side language PL/pgSQL by default (Bruce Momjian)
-
-
- Changes
-
- SQL Features
-
-
-
- Disallow comments on columns of relation types
- other than tables, views, and composite types, that is,
- sequences and TOAST tables.
-
-
-
-
- Adjust naming of indexes and their columns. Index
- expression columns are now named after the FigureColname
- result for their expressions, rather than always being
- "pg_expression_N". Digits are appended to this name if
- needed to make the column name unique within the index.
- Default names for indexes and associated constraints now
- include the column names of all their columns, not only the
- first one as in previous practice.
-
-
-
-
- Allow the index name to be omitted in CREATE INDEX,
- causing the system to choose an index name the same as it
- would do for an unnamed index constraint. A necessary
- side-effect is to promote the word CONCURRENTLY to a more
- reserved status; it can't be a table/column/index name
- anymore unless quoted.
-
-
-
-
- Improve the handling of SET CONSTRAINTS commands by
- having them search pg_constraint before searching pg_trigger.
- This allows saner handling of corner cases.
-
-
-
-
- Typed table feature; this adds the CREATE TABLE
- name OF type command.
-
-
-
-
- Tighten integrity checks on ALTER TABLE ... RENAME
- COLUMN in inheritance hierarchies.
-
-
-
-
- Replace the pg_listener-based LISTEN/NOTIFY
- mechanism with an in-memory queue. In addition, add support
- for a "payload" string to be passed along with each notify
- event.
-
-
- This implementation should be significantly more
- efficient than the old one, and is also more compatible with
- Hot Standby usage. There is not yet any facility for HS
- slaves to receive notifications generated on the master,
- although such a thing is possible in future.
-
-
-
-
- Have SELECT and CREATE TABLE AS queries return a
- row count. While this is invisible in psql, other
- interfaces, like libpq, make this value visible.
-
-
-
-
- Extend the set of frame options supported for
- window functions. This allows the frame to start from
- CURRENT ROW (in either RANGE or ROWS mode), and it also adds
- support for ROWS n PRECEDING and ROWS n FOLLOWING start and
- end points.
-
-
-
-
- Add DO statement to support execution of procedural language
- code without having to create a function for it.
-
-
-
-
- Support use of function argument names to identify which
- actual arguments match which function parameters. The syntax
- uses AS, for example funcname(value AS arg1, anothervalue AS
- arg2).
-
-
-
-
- Remove previously deprecated configuration
- parameter add_missing_from. The system now always behaves as
- though add_missing_from were off.
-
-
-
-
- Performance and behavioral improvements in UPDATE,
- DELETE, and SELECT FOR UPDATE/SHARE queries with joins.
- Fix various corner cases that could have resulted in duplicated output
- rows. Set-returning functions are now prohibited in the
- target list of SELECT FOR UPDATE/SHARE. FOR UPDATE does not
- propagate into a WITH query anymore.
-
-
-
-
- Fix SELECT FOR UPDATE/SHARE in conjunction with LIMIT.
- Previously, it could return fewer rows than the limit specified.
-
-
-
-
- Add a WHEN clause to CREATE TRIGGER, allowing a boolean expression
- to be checked to determine whether the trigger should be fired.
-
-
- For BEFORE triggers this is mostly a matter of spec compliance; but
- for AFTER triggers it can provide a noticeable performance
- improvement, since queuing of a deferred trigger event and
- re-fetching of the row(s) at end of statement can be
- short-circuited if the trigger does not need to be fired.
-
-
-
-
- Add exclusion constraints, which generalize the concept of
- uniqueness to support any indexable commutative operator, not just
- equality. Two rows violate the exclusion constraint if
- "row1.col OP row2.col" is TRUE for each of the columns in
- the constraint.
-
-
-
-
- Support ORDER BY within aggregate function calls, at long last
- providing a non-kluge method for controlling the order in which
- values are fed to an aggregate function. At the same time eliminate
- the old implementation restriction that DISTINCT was only supported
- for single-argument aggregates.
-
-
- Behavioral change: formerly, agg(DISTINCT x) dropped null values of
- x unconditionally. Now, it does so only if the aggregate's transition
- function is strict; otherwise nulls are treated as DISTINCT
- normally would, i.e., you get one copy.
-
-
-
-
- Add SQL-compliant triggers on columns, which fire only if
- certain columns are named in the UPDATE's SET list.
-
-
-
-
- Add CREATE LIKE INCLUDING COMMENTS and STORAGE, and INCLUDING
- ALL shortcut to allow users to make an exact copy of a table including
- all options and features.
-
-
-
-
- Define a new, more extensible syntax for COPY options
- in order to support additional COPY options in the future.
-
-
-
-
- Modify the definition of window-function PARTITION
- BY and ORDER BY clauses so that their elements are always
- taken as simple expressions over the query's input
- columns. This fixes a bug.
-
-
-
-
- Fix bug with nested WITH RECURSIVE statements.
-
-
-
-
- Add surrogate pair support for U& string and identifier
- syntax.
-
-
-
-
- Add Unicode escapes in E'...' strings.
-
-
-
-
- DROP COLUMN and DROP CONSTRAINT now support an IF EXISTS clause so
- that users can avoid fatal errors when running repeatable scripts.
-
-
-
-
- UNIQUE constraints can now be DEFERRABLE. This is primarily useful
- for incremental updates of numerical keys, e.g. "ID = ID +
- 1"
-
-
-
-
- Allow parentheses around the query expression that follows a WITH
- clause.
-
-
-
-
- INFORMATION_SCHEMA, a catalog of standard views of database
- objects, has been updated to the SQL:2008 standard.
-
-
-
-
- Change character_octet_length to more sensible values in
- INFORMATION_SCHEMA.
-
-
-
-
- Allow * as parameter for FORCE QUOTE for COPY CSV, so that all
- columns will be quoted.
-
-
-
-
-
- Performance
-
-
-
- Support "x IS NOT NULL" clauses as index-scan
- conditions.
-
-
-
-
- When estimating the selectivity of an inequality
- "column > constant" or "column < constant", and the
- comparison value is in the first or last histogram bin or
- outside the histogram entirely, try to fetch the actual
- column min or max value using an index scan (if there is an
- index on the column). If successful, replace the lower or
- upper histogram bound with that value before carrying on with
- the estimate. This limits the estimation error caused by
- moving min/max values when the comparison value is close to
- the min or max.
-
-
-
-
- Generic implementation of red-black binary tree.
- For now, only GIN uses it during index creation. Using
- self-balanced tree greatly speeds up index creation in corner
- cases with preordered data.
-
-
-
-
- Allow rewriting forms of ALTER TABLE to skip WAL
- logging.
-
-
-
-
- Speed up INFORMATION_SCHEMA's privilege views.
-
-
-
-
- Make TRUNCATE do truncate-in-place when processing
- a relation that was created or previously truncated in the
- current (sub)transaction.
-
-
-
-
- Implement "join removal" for cases where the inner side
- of a left join is unique and is not referenced above the join. This should
- speed up many ORM-generated and reporting tool queries.
-
-
-
-
- Remove the use of the flat files pg_auth and
- pg_database in order to improve performance. (Warning: pgbouncer
- and possibly other tools currently suggest referring to the pg_auth
- file for its user database. Such schemes will no longer work.)
-
-
-
-
- EXPLAIN allows output of plans in XML, JSON, or YAML format for automated
- processing of explain plans by analysis or visualization tools.
-
-
-
-
- EXPLAIN now supports the use of generic options in EXPLAIN ( option
- value, ... ) format, which permits the creation of additional
- EXPLAIN options.
-
-
-
-
- ALTER TABLE ... ALTER COLUMN ... SET STATISTICS DISTINCT allows
- users to manually tweak the number of distinct values estimated for
- a column, to fix cases where ANALYZE estimates are incorrect.
-
-
-
-
- Make GEQO's planning deterministic by having it start from a
- predictable random number seed each time.
-
-
-
-
- Rewrite GEQO's gimme_tree function so that it always finds a legal
- join sequence. Previously, it could have failed to produce a plan
- in some cases.
-
-
-
-
- Tweak TOAST code so that columns marked with MAIN storage strategy
- are not forced out-of-line unless that is necessary to make the row
- fit on a page. Previously, they were forced out-of-line if needed
- to get the row down to the default target size (1/4th page).
-
-
-
-
- Simplify the forms foo <> true and foo <> false to foo
- = false and foo = true during query optimization.
-
-
-
-
- Avoid per-send() system calls to manage SIGPIPE in libpq, if the
- platform provides either sockopt(SO_NOSIGPIPE) or the MSG_NOSIGNAL
- flag to send().
-
-
-
-
-
- Administration and Monitoring
-
-
-
- Add the ability to store inheritance-tree
- statistics in pg_statistic, and teach ANALYZE to compute such
- stats for tables that have subclasses.
-
-
-
-
- Revise pgstat's tracking of tuple changes to
- improve the reliability of decisions about when to
- auto-analyze. The previous code depended on n_live_tuples +
- n_dead_tuples - last_anl_tuples, where all three of these
- numbers could be bad estimates from ANALYZE itself. Even
- worse, in the presence of a steady flow of HOT updates and
- matching HOT-tuple reclamations, auto-analyze might never
- trigger at all, even if all three numbers are exactly right,
- because n_dead_tuples could hold steady.
-
-
-
-
- Support ALTER TABLESPACE name SET/RESET (
- tablespace_options ), currently supporting seq_page_cost and
- random_page_cost as parameters.
-
-
-
-
- New faster implementation of VACUUM FULL. The old
- idiom of using CLUSTER instead of VACUUM FULL for speed is
- now obsolete.
-
-
-
-
- Add buffer access counters to
- pg_stat_statements.
-
-
-
-
- Add some simple support and documentation for using
- process-specific oom_adj settings to prevent the postmaster
- from being OOM-killed on Linux systems.
-
-
-
-
- Place tablespace directories in their own
- subdirectory so pg_migrator can upgrade clusters without
- renaming the tablespace directories.
-
-
-
-
- Introduce Streaming Replication.
-
-
-
-
- Add pg_table_size() and pg_indexes_size() to
- provide more user-friendly wrappers around the
- pg_relation_size() function.
-
-
-
-
- Add pg_stat_reset_shared('bgwriter') to reset the
- cluster-wide shared statistics of the bgwriter.
-
-
-
-
- Replace ALTER TABLE ... SET STATISTICS DISTINCT
- with a more general mechanism. Attributes can now have
- options, just as relations and tablespaces do, and the
- reloptions code is used to parse, validate, and store
- them.
-
-
-
-
- Fix longstanding gripe that we check for
- 0000000001.history at start of archive recovery, even when we
- know it is never present.
-
-
-
-
- Make standby server continuously retry restoring
- the next WAL segment with restore_command, if the connection
- to the primary server is lost. This ensures that the standby
- can recover automatically, if the connection is lost for a
- long time and standby falls behind so much that the required
- WAL segments have been archived and deleted in the
- master.
-
-
- This also makes standby_mode useful without
- streaming replication; the server will keep retrying
- restore_command every few seconds until the trigger file is
- found. That's the same basic functionality pg_standby
- offers, but without the bells and whistles.
-
-
-
-
- Add functions to reset the statistics counter for a
- single table/index or a single function.
-
-
-
-
- Augment EXPLAIN output with more details on Hash
- nodes.
-
-
-
-
- Reindexing shared system catalogs is now fully
- transactional and crash-safe.
-
-
-
-
- Allow read-only connections during recovery, also
- known as Hot Standby. This provides a built-in master-slave
- replication solution.
-
-
-
-
- Provide a parenthesized-options syntax for VACUUM, analogous to
- that recently adopted for EXPLAIN. This will allow additional
- options to be implemented in future without having to make them
- fully-reserved keywords. The old syntax remains available for
- existing options, however.
-
-
-
-
- Add support for an application_name parameter, which is displayed
- in pg_stat_activity and recorded in log entries.
-
-
-
-
- Fix longstanding problems in VACUUM caused by untimely
- interruptions.
-
-
-
-
- Add YAML to list of EXPLAIN formats.
-
-
-
-
- Add an EXPLAIN (BUFFERS) option to show buffer-usage statistics.
-
-
-
-
- Add a hook to let loadable modules get control at ProcessUtility
- execution, and use it to extend contrib/pg_stat_statements to track
- utility commands.
-
-
-
-
- Add a Boolean server configuration parameter
- "bonjour" to control whether a Bonjour-enabled
- build actually attempts to advertise itself via Bonjour.
-
-
-
-
- When reloading postgresql.conf, log what parameters actually
- changed.
-
-
-
-
- Make it possibly to specify server configuration parameters
- per user-database combination. Add a \drds command to psql to
- display the settings.
-
-
-
-
- Allow the collection of statistics on sequences.
-
-
+
+
+
+
+ Allow PL/pgSQL to handle row types with dropped columns (Pavel Stehule)
+
+
+
+
+
+ Allow IN parameters to be assigned values within
+ PL/pgSQL functions (Steve Prentice)
+
+
+
+
+
+ Improve error location reporting in PL/pgSQL (Tom Lane)
+
+
+
+
+
+ Have PL/pgSQL use the main lexer, rather than a custom version (Tom Lane)
+
+
+
+
+
+
+
+
+ <link linkend="plpgsql-cursors">PL/pgSQL Cursors</link>
+
+
+
+
+ Add count and ALL options to MOVE
+ FORWARD/BACKWARD in PL/pgSQL (Pavel Stehule)
+
+
+
+
+
+ Allow PL/pgSQL's WHERE CURRENT OF to use a cursor
+ variable (Tom Lane)
+
+
+
+
+
+ Add PL/pgSQL's OPEN cursor FOR EXECUTE to use parameters
+ (Pavel Stehule, Itagaki Takahiro)
+
+
+
+ This is accomplished with a new USING clause.
+
+
+
+
+
+
+
+
+ <link linkend="plperl">PL/Perl</link> Server-Side Language
+
+
+
+
+ Add new PL/Perl functions: quote_literal(),
+ quote_nullable(), quote_ident(),
+ encode_bytea(), decode_bytea(),
+ looks_like_number(),
+ encode_array_literal(),
+ encode_array_constructor() (Tim Bunce)
+
+
+
+
+
+ Add server variable plperl.on_init to
+ specify a PL/Perl Perl initialization function (Tim
+ Bunce)
+
+
+
+ plperl.on_plperl_init
+ and plperl.on_plperlu_init are also available
+ for trusted/untrusted-specific initialization.
+
+
+
+
+
+ Improve error context support in PL/Perl (Alexey Klyukin)
+
+
+
+
+
+ Support END blocks in PL/Perl (Tim Bunce)
+
+
+
+ END blocks do not currently allow database access.
+
+
+
+
+
+ Allow use strict in PL/Perl (Tim Bunce)
+
+
+
+ This can be enabled with the server variable plperl.use_strict.
+
+
+
+
+
+ Allow require in PL/Perl (Tim Bunce)
+
+
+
+ This basically tests to see if the module is loaded, and if not,
+ generates an error.
+
+
+
+
+
+ Allow use feature in PL/Perl if Perl version 5.10 or
+ later is used (Tim Bunce)
+
+
+
+
+
+ Verify that PL/Perl return values are valid in the server encoding
+ (Andrew Dunstan)
+
+
+
+
+
+ Improve PL/Perl code structure (Tim Bunce)
+
+
+
+
+
+ PL/Perl subroutines are now given names (Tim Bunce)
+
+
+
+ This is for the use of profiling and code coverage tools. DIDN'T
+ THEY HAVE NAMES BEFORE?
+
+
+
+
+
+ PL/Perl no longer allows Safe version 2.20 because
+ it is unsafe (Tim Bunce)
+
+
+
+
+
+
+
+
+ <link linkend="plpython">PL/Python</link> Server-Side Language
+
+
+
+
+ Add Unicode support in PL/Python (Peter Eisentraut)
+
+
+
+ Strings are automatically converted from/to the server encoding as
+ necessary.
+
+
+
+
+
+ Improve bytea support in PL/Python (Caleb Welton)
+
+
+
+ Bytea values passed into PL/Python now are represented as
+ binary, rather than the Postgres bytea text format. Null
+ bytes are now also output properly from PL/Python. Boolean
+ and numeric value passing in PL/Python was also improved.
+
+
+
+
+
+ Add array parameter/return
+ support to PL/Python (Peter Eisentraut)
+
+
+
+
+
+ Improve mapping of domains to Python base types in PL/Python (Peter Eisentraut)
+
+
+
+
+
+ Add Python 3 support to PL/Python (Peter Eisentraut)
+
+
+
+ The new server-side language is called plpython3u.
+
+
+
+
+
+ Improve error location and exception reporting in PL/Python (Peter Eisentraut)
+
+
+
+
+
+
+
+
+
+
+ Client Applications
+
+
+
+
+ Add vacuumdb
+
+
+
+
+
+
+ <link linkend="APP-PSQL"><application>psql</></link>
+
+
+
+
+ Properly escape psql variables and
+ identifiers (Pavel Stehule, Robert Haas)
+
+
+
+ For example, :'var' will be escaped as a literal string, and
+ :"var" will be escaped as an SQL identifier.
+
+
+
+
+
+ Ignore leading UTF-8-encoded Unicode byte-order marker in
+ psql (Itagaki Takahiro)
+
+
+
+ This is enabled when the client encoding is UTF-8.
+
+
+
+
+
+ Fix psql --file - to properly honor
+
+
+
+
+ Prevent overwriting of psql's command-line history
+ if two psql sessions are run simultaneously (Tom Lane)
+
+
+
+
+
+ Improve psql's tab completion support (Itagaki
+ Takahiro)
+
+
+
+
+
+
+ <application>psql</> Display
+
+
- Increase the maximum value of extra_float_digits to
- 3, and have pg_dump use that value when the backend is new
- enough to allow it, because it is possible to need 3 extra
- digits for float4 values (but not for float8 values).
+ Allow psql to use fancy Unicode line-drawing
+ characters via \pset linestyle unicode (Roger Leigh)
-
-
- Add the ability to include the SQLSTATE error code of any error
- messages in the PostgreSQL activity log with the new
- log_line_prefix placeholder %e.
-
-
-
-
- Show the exact value being complained of in
- unique-constraint-violation error messages, including unique-index
- build failures.
-
-
-
-
-
- Security
-
-
-
- Add support for RADIUS authentication.
-
-
-
-
- When querying a table with child tables, do not check permissions
- on the child tables, only on the parent table. The old behavior was
- found to be useless and confusing in virtually all cases, and also
- contrary to the SQL standard.
-
-
-
-
- Add a hook to CREATE/ALTER ROLE to allow an external module to
- check the strength of database passwords, and create a sample
- implementation of such a hook as a new contrib module
- "passwordcheck".
-
-
-
-
- Add large object access control.
-
-
-
-
- Allow LDAP authentication to operate in search+bind
- mode, meaning it does a search for the user in the directory
- first, and then binds with the DN found for this user. This
- allows for LDAP logins in scenarios where the DN of the user
- cannot be determined simply by prefix and suffix, such as the
- case where different users are located in different
- containers. The old way of authentication can be
- significantly faster, so it's kept as an option.
-
-
-
-
- Add ALTER DEFAULT PRIVILEGES command, which allows
- users to adjust the privileges that will be applied to
- subsequently-created objects.
-
-
-
-
- Add GRANT/REVOKE ON ALL TABLES/SEQUENCES/FUNCTIONS IN SCHEMA.
- This makes it easier to manage permissions on database objects.
-
-
-
-
- Support "samehost" and "samenet" specifications
- in pg_hba.conf. This allows users with dynamic server addresses to run
- PostgreSQL without frequently modifying pg_hba.conf.
-
-
-
-
- New has_sequence_privilege() functions allow you to check sequence
- privileges for a given ROLE.
-
-
-
-
-
- Built-In Functions
-
-
-
- Fix 3-parameter form of bit substring() to throw
- error for negative length, as required by SQL
- standard.
-
-
-
-
- Add get_bit/set_bit functions for bit strings,
- paralleling those for bytea, and implement OVERLAY() for bit
- strings and bytea.
-
-
-
-
- Add string_agg aggregate functions. The
- one-argument version concatenates the input values into a
- string. The two-argument version also does the same thing,
- but inserts delimiters between elements.
-
-
-
-
- Honor to_char() "FM" specification in YYY, YY, and
- Y; it was already honored by YYYY.
-
-
-
-
- Remove configuration parameter regex_flavor. It is now always
- "advanced".
-
-
-
-
- Teach the regular expression functions to do case-insensitive
- matching and locale-dependent character classification properly
- when the database encoding is UTF8. This previously only worked
- correctly for single-byte encodings. It is still broken for other
- multibyte encodings.
-
-
-
-
- Support POSIX-compatible interpretation of ? as well as {m,n}
- and related constructs in SIMILAR TO, per SQL:2008.
-
-
-
-
- The to_char() formatting functions now supports EEEE (scientific
- notation).
-
-
-
-
- Use floor() not rint() when reducing precision of fractional
- seconds in timestamp_trunc, timestamptz_trunc, and interval_trunc()
- for the float-datetime case. This improves accuracy of time
- calculations.
-
-
-
-
- Fix ancient bug in handling of to_char() modifier 'TH', when used
- with HH.
-
-
-
-
-
- Data Types
-
-
-
- Allow enums to be created with zero labels, for use
- during binary upgrade.
-
-
-
-
- When doing "ARRAY[...]::domain", where domain is a domain
- over an array type, we need to check domain constraints. Regression
- introduced in 8.4.
-
-
-
-
- Fix integer-to-bit-string conversions to handle the first
- fractional byte correctly when the output bit width is wider than
- the given integer by something other than a multiple of 8 bits.
-
-
-
-
- Fix encoding handling in binary input function of xml type.
-
-
-
-
- Tighten binary receive functions so that they reject values
- that the text input functions don't accept either.
-
-
-
-
- New hex-string input and output format options for type bytea. Hex
- output format is enabled by default, which is an incompatible
- change. See the new bytea_output parameter if you need to restore
- compatibility.
-
-
-
-
- Adds prefix support for text search synonym dictionary, allowing
- creation of synonyms on partial matches.
-
-
-
-
-
- Server Tools
-
-
-
- initdb now selects the encoding SQL_ASCII when the locale specifies
- US-ASCII. This case previously failed.
-
-
-
-
- Add init[db] option to pg_ctl.
-
-
-
-
- It is now reasonably safe to use pg_ctl to start
- the postmaster from a boot-time script.
-
-
-
-
- pg_dump/pg_restore --clean now drops large objects.
-
-
-
-
- Modify parallel pg_restore ordering logic to avoid a potential
- O(N^2) slowdown for some complex databases.
-
-
-
-
-
- libpq
-
-
-
- Add user-specific .pg_service.conf file.
-
-
-
-
- Add new escaping functions PQescapeLiteral and
- PQescapeIdentifier.
-
-
-
-
- Introduce two new libpq connection functions,
- PQconnectdbParams and PQconnectStartParams, which are
- analogous to PQconnectdb and PQconnectStart respectively, but
- accept two NULL-terminated arrays, keywords and values,
- rather than conninfo strings. This avoids the need to build
- the conninfo string in cases where it might be inconvenient
- to do so.
-
-
-
-
- Throw error when a specified connection service name is not
- found in pg_service.conf, instead of ignoring it.
-
-
-
-
- Make libpq reject non-numeric and out-of-range port numbers with a
- suitable error message.
-
-
-
-
-
- psql
-
-
-
- Allow psql variables to be interpolated with
- literal or identifier escaping.
-
-
-
-
- In psql, show view definition only with \d+, not with \d.
-
-
-
-
- In psql, ignore UTF-8-encoded Unicode byte-order mark at the
- beginning of a file if the client encoding is UTF-8.
-
-
-
-
- Improve psql's tabular display of wrapped-around data by inserting
- markers in the formerly-always-blank columns just to left and right
- of the data. "pset linestyle old-ascii" is added to make
- the previous behavior available if anyone really wants it.
-
-
-
-
- Simplify psql's new linestyle behavior to default to
- linestyle=ascii all the time, rather than hoping we can tell
- whether the terminal supports UTF-8 characters.
-
-
-
-
- Implement significantly saner behavior when two or
- more psql sessions overlap in their use of the history file.
-
-
-
-
- Add "pset linestyle ascii/unicode" option to psql,
- allowing our traditional ASCII-art style of table output to
- be upgraded to use Unicode box drawing characters if
- desired.
-
-
-
-
- Have \d show child tables that inherit from the specified parent
-
-
-
-
- psql now shows the index methods in \di
-
-
-
-
-
- Procedural Languages
-
- PL/pgSQL
-
-
-
- Add "USING expressions" option to PL/pgSQL's OPEN
- cursor FOR EXECUTE.
-
-
-
-
- PL/pgSQL is installed by default.
-
-
-
-
- Remove PL/pgSQL's RENAME declaration, which has
- bizarre and mostly nonfunctional behavior, and is so little
- used that no one has been interested in fixing it. To ensure
- that possible uses are covered, remove the ALIAS declaration's
- arbitrary restriction that only $n identifiers can be
- aliased.
-
-
-
-
- The PL/pgSQL parser and scanner were reworked to behave much more
- sanely:
-
-
- A variable reference will only be recognized where it can validly
- go, ie, a place where a column value or parameter would be legal,
- instead of the former behavior that would replace any textual match
- including table names and column aliases (leading to syntax errors
- later on).
-
-
- When a name could refer either to a PL/pgSQL variable or a
- table column, PL/pgSQL formerly always assumed the variable was
- meant, sometimes resulting in surprising behavior. Now, PL/pgSQL
- can assume the variable is meant, or assume the table column is
- meant, or throw an error in ambiguous cases. For safety the default
- is to throw error. To configure this see the PL/pgSQL documentation.
-
-
- Error reporting is much nicer: it no longer shows edited
- versions of statements that look significantly different from what
- you wrote.
-
-
- Note that this change affects the set of keywords that are
- reserved in PL/pgSQL (i.e., cannot be the name of a PL/pgSQL
- variable). Now, all keywords shown as reserved in Appendix C are reserved for
- PL/pgSQL purposes as well. However, many PL/pgSQL-only keywords
- that were formerly treated as reserved no longer are. As in regular
- SQL, you can double-quote a variable's name if you want to use a
- name that conflicts with a reserved keyword.
-
-
-
-
- PL/pgSQL IN parameters now accept value assignments.
-
-
-
-
- Allow cursor commands MOVE FORWARD n, MOVE BACKWARD n,
- MOVE FORWARD ALL, MOVE BACKWARD ALL in PL/pgSQL.
-
-
-
-
- PL/pgSQL functions can now better cope with row types
- containing dropped columns.
-
-
-
-
-
-
- PL/Perl
-
-
-
- Add utility functions to PL/Perl: quote_literal,
- quote_nullable, quote_ident, encode_bytea, decode_bytea,
- looks_like_number, encode_array_literal,
- encode_array_constructor.
-
-
-
-
- Add plperl.on_plperl_init, plperl.on_plperlu_init,
- and plperl.on_init settings for startup code.
-
-
-
-
- Allow (ineffective) use of "require". If the
- required module is not already loaded then it dies. So "use
- strict;" now works in PL/Perl.
-
-
-
-
- Pre-load the feature module if Perl >= 5.10.
- So "use feature :5.10;" now works in PL/Perl.
-
-
-
-
- Stored procedure subs are now given names. The
- names are not visible in ordinary use, but they make tools
- like Devel::NYTProf and Devel::Cover much more
- useful.
-
-
-
-
- Handle END blocks in PL/Perl.
-
-
-
-
- Clean up package namespace use and use of Safe.
-
-
-
-
- Change log level of Perl warnings from NOTICE to
- WARNING.
-
-
-
-
- Add support for anonymous code blocks (DO blocks) to PL/Perl.
-
-
-
-
- Improve error context reporting in PL/Perl, for
- easier debugging.
-
-
-
-
- Convert a Perl array to a PostgreSQL array when returned by
- set-returning functions as well as non-SRFs.
-
-
-
-
-
-
- PL/Python
-
-
-
- Improved printing of Python exceptions in
- PL/Python.
-
-
-
-
- Add PL/Python DO handler.
-
-
-
-
- Support arrays as parameters and return values of PL/Python
- functions.
-
-
-
-
- Add Python 3 support to PL/Python. It behaves more or less
- unchanged compared to Python 2, but the new language variant is
- called plpython3u.
-
-
-
-
- Fix/improve bytea and boolean support in PL/Python. Data type
- conversion into and out of PL/Python previously went through
- an intermediate string representation, which caused various
- discrepancies especially with bytea and boolean data. This is
- now fixed by converting the values directly.
-
-
-
-
- PL/Python now accepts Unicode objects where it previously
- only accepted string objects (for example, as return
- value). Unicode objects are converted to the PostgreSQL
- server encoding as necessary.
-
-
-
-
- Improve error context reporting in PL/Python, for easier
- debugging.
-
-
-
-
- Greatly expand the regression testing for PL/Python.
-
-
-
-
-
-
-
- Additional Supplied Modules
-
-
-
- Add query text to auto_explain output.
-
-
-
-
- Add \shell and \setshell meta commands to pgbench.
-
-
- \shell runs an external shell command. \setshell
- does the same and assigns the result to a variable.
-
-
-
-
- Multiple improvements in contrib/hstore, including
- raising limits on keys and values, conversions to and from
- records and arrays, and support for GROUP BY and DISTINCT.
-
-
-
-
- pgbench is now multi-threaded, allowing it to use multiple CPU's
- for its client connections, and to do more realistic workload
- testing.
-
-
-
-
- Added the ability to retrieve asynchronous notifications using
- dblink, via the addition of the function dblink_get_notify().
-
-
-
-
- Added matchorig, matchsynonyms, and keepsynonyms options to
- contrib/dict_xsyn.
-
-
-
-
- Added contrib/unaccent.
-
-
-
-
-
- ECPG
-
-
-
- Add sqlda support in both native and compatibility
- mode.
-
-
-
-
- Fix SQL3 type return value: For non-SQL3 types ECPG
- used to return -OID. This will break if there are enough OIDs
- to fill the namespace. Therefore we play it safe and return
- 0 if there is no OID->SQL3 type mapping available.
-
-
-
-
- Make char the default sqlda type.
-
-
-
-
- Add DESCRIBE [OUTPUT] statement.
-
-
-
-
- Add out-of-scope cursor support to native mode.
-
-
-
-
- Refactor ECPG grammar so that it uses the core grammar's
- unreserved_keyword list, minus a few specific words that have to be
- treated specially. This de-reserves a number of words in ECPG.
-
-
-
-
- Added dynamic cursor names to ECPG.
-
-
- Add ECPG function that returns the current transaction status.
+ Improve display of wrapped columns in psql (Roger
+ Leigh)
+
+
+
+ The previous format is available by using \pset linestyle
+ old-ascii.
+
+
+
+
+
+
+ <application>psql</> <link
+ linkend="APP-PSQL-meta-commands"><command>\d</></link>
+ Commands
+
+
- Make ECPG more robust against applications freeing strings.
+ Have \d show child tables that inherit from the specified
+ parent (Damien Clochard)
+
+
+
+ \d shows only the number of child tables, while
+ \d+ shows the names of all child tables.
-
-
- ECPG now includes a STRING datatype for Informix compatibility
- mode.
-
-
-
-
-
- Ports
+
+
+
+ Show definition of indexes in \d index_name (Khee Chin)
+
+
+
+ The definition is useful for expression indexes.
+
+
+
+
+
+ In psql, show the view definition only with \d+,
+ not with \d (Peter Eisentraut)
+
+
+
+
+
+
+
+
+
+ <link linkend="APP-PGDUMP"><application>pg_dump</></link>
+
+
+
+
+ Have pg_dump/pg_restore
+
+
+
+
+
+ Fix pg_dump to properly dump large objects if
+ standard_conforming_strings is enabled (Tom Lane)
+
+
+
+ Large objects dumps now use hex format for output. (SWITCH DEFAULT
+ FOR BETA? TOM)
+
+
+
+
+
+ Allow pg_dump to dump comments attached to columns
+ of composite types (Taro Minowa (Higepon))
+
+
+
+
+
+ Have pg_dump
+
+
+ These were already present in custom output mode.
+
+
+
+
+
+
+
+
+ <link
+ linkend="app-pg-ctl"><application>pg_ctl</></link>
+
+
+
+
+ Allow pg_ctl to be safely used to start the
+ postmaster at boot-time (Tom Lane)
+
+
+
+ Previously the pg_ctl process could have been mistakenly
+ identified as a running postmaster based on a stale
+ postmaster lock file.
+
+
+
+
+
+ Give pg_ctl the ability to initialize the database
+ (like initdb) (Zdenek Kotala)
+
+
+
+
+
+
+
+
+
+
+
+ <application>Development Tools</>
+
+
+ <link linkend="libpq"><application>libpq</></link>
+
+
+
+
+
+ Add new libpq functions
+ PQconnectdbParams()
+ and PQconnectStartParams() (Guillaume
+ Lelarge)
+
+
+
+ These functions are similar to PQconnectdb() and
+ PQconnectStart() except they allow a null-terminated
+ array of connection options, rather than requiring all options to
+ be sent in a single string.
+
+
+
+
+
+ Add libpq functions PQescapeLiteral()
+ and PQescapeIdentifier() (Robert Haas)
+
+
+
+ These functions return appropriately quoted and escaped literal
+ strings and identifiers. The caller is not required to pre-allocate
+ the string result, as is required by PQescapeStringConn().
+
+
+
+
+
+ Add checking for a per-user service file (.pg_service.conf),
+ which is checked before the site-wide service file
+ (Peter Eisentraut)
+
+
+
+ The file .pg_service.conf is assumed to be in the
+ user's home directory.
+
+
+
+
+
+ Properly report an error if the specified libpq service
+ cannot be found (Peter Eisentraut)
+
+
+
+
+
+ Issue a warning if the .pgpass-retrieved
+ password fails (Bruce Momjian)
+
+
+
+
+
+
+
+
+ <link linkend="ecpg"><application>ecpg</></link>
+
+
+
+
+ Add SQLDA
+ (SQL Descriptor Area) support to ecpg
+ (Boszormenyi Zoltan)
+
+
+
+
+
+ Add the DESCRIBE
+ [OUTPUT] statement to ecpg
+ (Boszormenyi Zoltan)
+
+
+
+
+
+ Add an ecpg function to return the
+ current transaction status (Bernd Helmle)
+
+
+
+
+
+ Add the string data type in ecpg
+ Informix-compatibility mode (Zoltan Boszormenyi)
+
+
+
+
+
+ Allow ecpg to use new and old
+ variable names without restriction (Michael Meskes)
+
+
+
+
+
+ Allow ecpg to use variable names in
+ free()(Michael Meskes)
+
+
+
+
+
+ Have ecpg return zero for non-SQL3 data types
+ (Michael Meskes))
+
+
+
+ Previously it returned the negative of the data type oid.
+
+
+
+
+
+
+ <application>ecpg</> Cursors
-
-
- Add basic build support for Visual Studio 2008,
- without resorting to generating the build files for 2005 and
- then converting them.
-
-
-
-
- Added support for 64-bit Windows platforms.
-
-
-
-
- Disable triggering failover with a signal in pg_standby on Windows.
- It never really worked before anyway.
-
-
-
-
- Change the WIN32 API version to be 5.01 (Windows XP), to
- bring in the proper IPv6 headers in newer SDKs.
-
-
-
-
- Write to the Windows eventlog in UTF-16, converting the
- message encoding as necessary.
-
-
-
-
- Replace use of the long-deprecated Bonjour API
- DNSServiceRegistrationCreate with the not-so-deprecated
- DNSServiceRegister. The new code will fail on Mac OS X
- releases before 10.3.
-
-
-
-
- Reserve the shared memory region during backend startup on Windows,
- so that memory allocated by starting third party DLLs doesn't end
- up conflicting with it. Hopefully this solves the long-time issue
- with "could not reattach to shared memory" errors on
- Win32.
-
-
-
-
- Add s_lock support for SuperH architecture (not well tested).
-
-
-
-
-
- Source Code, Build Options
-
-
-
- Improve PGXS makefile system to allow the module's
- makefile to specify where to install DATA and DOCS files.
- This is mainly intended to allow versioned installation, eg,
- install into contrib/fooM.N/ rather than directly into
- contrib/.
-
-
-
-
- Get rid of the need for manual maintenance of the
- initial contents of pg_attribute, by having genbki.pl derive
- the information from the various catalog header files. This
- greatly simplifies modification of the "bootstrapped"
- catalogs. This patch finally kills genbki.sh and
- Gen_fmgrtab.sh; we now rely entirely on Perl scripts for
- those build steps. To avoid creating a Perl build dependency
- where there was not one before, they will be built and
- shipped in tarballs.
-
-
-
-
- Move the default configuration for the MSVC build
- system to config_default.pl, and allow using config.pl to
- override the defaults.
-
-
-
-
- Make configure check the version of Perl we're
- building with, and reject versions < 5.8.
-
-
-
-
- Remove all support for working around on systems
- that don't provide a working 64-bit integer type.
-
-
-
-
- Add new make targets "world", "install-world" and
- "installcheck-world" to build, install and check just about
- everything. In addition to everything built installed and
- tested by all, install and installcheck targets, these build
- HTML documentation, build and test contrib, and test
- procedural languages and ECPG.
-
-
-
-
- configure --enable-thread-safety is now the default (but can still
- be turned off).
-
-
-
-
- Fix inclusions of readline/editline header files so that we
- only attempt to #include the version of history.h that is in
- the same directory as the readline.h we are using. This
- avoids problems in some scenarios where both readline and
- editline are installed.
-
-
-
-
- Derived files that are shipped in the distribution used to be
- built in the source directory even for out-of-tree
- builds. They are now built in the build tree. This
- should be more convenient for certain developers' workflows.
-
-
-
-
- Functions which conflict with C++ reserved words have been renamed,
- making backend header files now safe to use with C++ libraries.
-
-
-
-
- Add man pages for SPI functions.
-
-
-
-
- Upgrade to Autoconf 2.63 (not relevant to users of distribution
- tarballs).
-
-
-
-
- Minimum version of Flex is now 2.5.31, to support reentrant
- scanners (not relevant to users of distribution tarballs).
-
-
-
-
- Documentation build rules have been improved. The generated
- documentation files are now shipped "loose", not in
- sub-tarballs.
-
-
-
-
- New toolchain to generate man pages. From now on, the man pages
- will be current in every release.
-
-
-
-
- Code-coverage testing support now extends to the entire source
- tree, not only src/backend/.
-
-
-
-
- Make the core scanner re-entrant, along with additional fixes that
- will let it be used directly by PL/pgSQL.
-
-
-
-
-
+
+
+
+ Add ecpg out-of-scope cursor support in native mode
+ (Boszormenyi Zoltan)
+
+
+
+ This allows DECLARE to use variables that are not in
+ scope when OPEN is called. This facility already existed
+ in ecpg Informix-compatibility mode.
+
+
+
+
+
+ Allow dynamic ecpg cursor names (Boszormenyi Zoltan)
+
+
+
+
+
+ Allow ecpg to use noise words FROM and
+ IN in FETCH and MOVE (Zoltan
+ Boszormenyi)
+
+
+
+
+
+
+
+
+
+
+
+
+ Build Options
+
+
+
+
+ Enable client thread safety by default (Bruce Momjian)
+
+
+
+ Thread-safe builds can be disabled with configure
+
+
+
+
+
+ Add a compile-time option to allow the Linux out-of-memory killer
+ to kill backends (Alex Hunsaker, Tom Lane)
+
+
+
+ Now that /proc/self/oom_adj allows disabling
+ of the Linux out-of-memory (OOM)
+ killer for the postmaster and its children, the new
+ compile-time option -DLINUX_OOM_ADJ=0
+ allows the killer to be enabled for postmaster
+ children. pg_config shows if this flag
+ was used during compilation.
+
+
+
+
+
+ Use DocBook XSL stylesheets for man page
+ building (Peter Eisentraut)
+
+
+
+
+
+
+ Makefiles
+
+
+
+
+ New Makefile targets world,
+ install-world, and installcheck-world
+ (Andrew Dunstan)
+
+
+
+ These are similar to the existing all, install,
+ and installcheck targets, but they build HTML
+ documentation, build and test /contrib, and test
+ server-side languages and ecpg.
+
+
+
+
+
+ Add data and documentation location control to PGXS Makefiles
+ (Mark Cave-Ayland)
+
+
+
+
+
+ Restructure the HTML documentation build
+ Makefile rules (Peter Eisentraut)
+
+
+
+
+
+
+
+
+ New Requirements
+
+
+
+
+ Require Autoconf 2.63 for building from source (Peter Eisentraut)
+
+
+
+
+
+ Require Flex 2.5.31 or later to build from source
+ (Tom Lane)
+
+
+
+
+
+ Require Perl version 5.8 or greater to build the server
+ from a CVS copy (John Naylor, Andrew)
+
+
+
+
+
+
+
+
+ Windows
+
+
+
+
+ Add support for compiling on 64-bit
+ Windows and running in 64-bit
+ mode (Tsutomu Yamada, Magnus)
+
+
+
+ This allows for large shared memory sizes on Windows.
+
+
+
+
+
+ Allow server builds using Visual Studio
+ 2008 (Magnus Hagander)
+
+
+
+
+
+ Allow multi-processor compilation using Microsoft Visual
+ C (Magnus Hagander)
+
+
+
+
+
+
+
+
+
+
+ Source Code
+
+
+
+
+ Distribute documentation in a proper directory tree, rather than
+ as tar archive files inside the main distribution tarball (Peter Eisentraut)
+
+
+
+ For example, the HTML documentation is now in
+ doc/src/sgml/html; the manual pages are packaged
+ similarly.
+
+
+
+
+
+ Enable the server lexer to be reentrant (Tom Lane)
+
+
+
+ This was needed for use of the lexer by PL/pgSQL.
+
+
+
+
+
+ Improve speed of memory allocation (Tom Lane, Greg Stark)
+
+
+
+
+
+ Add system columns to better document the use of indexes for constraint
+ enforcement (Tom Lane)
+
+
+
+
+
+ Allow multiple actions to be communicated using the same operating
+ system signal (Fujii Masao)
+
+
+
+ This allows improved backend communication as new features are
+ added.
+
+
+
+
+
+ Improve source code test coverage, including /contrib, PL/Python,
+ and PL/Perl (Peter Eisentraut, Andrew Dustan)
+
+
+
+
+
+ Remove the use of flat files for system table bootstrapping
+ (Tom Lane, Alvaro Herrera)
+
+
+
+ This also improves performance when using millions of users and
+ databases.
+
+
+
+
+
+ Improve the ability to translate psql strings
+ (Peter Eisentraut)
+
+
+
+
+
+ Reduce the length of some file names so file paths are less than
+ 100 characters (Tom Lane)
+
+
+
+ Some decompression programs have problems with long file names.
+
+
+
+
+
+ Tighten input requirements for int2 vector input (Caleb
+ Welton)
+
+
+
+
+
+ Add a new ERRCODE_INVALID_PASSWORD
+ SQLSTATE error code (Bruce Momjian)
+
+
+
+
+
+ Properly remove the few remaining personal source code copyright
+ entries (Bruce Momjian)
+
+
+
+ The personal copyright notices were insignificant but the community
+ occasionally had to answer questions about them.
+
+
+
+
+
+
+ Feature Support
+
+
+
+
+ Use a more modern API for Bonjour (Tom Lane)
+
+
+
+ Bonjour now requires OS X 10.3 or later.
+
+
+
+
+
+ Add processor test-and-test lock support for the SuperH
+ architecture (Nobuhiro Iwamatsu)
+
+
+
+
+
+ Allow non-GCC compilers to use inline functions if
+ they support them (Kurt Harriman)
+
+
+
+
+
+ Remove support for platforms that don't have a working 64-bit
+ integer data types (Tom Lane)
+
+
+
+ It is believed all supported platforms have working 64-bit integer
+ data types.
+
+
+
+
+
+
+
+
+
+ Server Programming
+
+
+
+
+ Allow use of C++ functions in backend code (Kurt
+ Harriman, Peter Eisentraut)
+
+
+
+ This removes keyword conflicts that previously made C++
+ usage difficult in backend code. extern "C" { } might still
+ be necessary.
+
+
+
+
+
+ Add AggCheckCallContext()
+ for use in detecting if a C function is
+ being called as an aggregate (Hitoshi Harada)
+
+
+
+
+
+ Require fastgetattr() and heap_getattr()
+ backend macros to use a non-NULL fourth argument (Robert Haas)
+ KEEP?
+
+
+
+
+
+
+
+
+ Server Hooks
+
+
+
+
+ Add parser hooks to access column and parameter references in
+ queries (Tom Lane)
+
+
+
+
+
+ Add a hook so loadable modules can control utility commands (Itagaki
+ Takahiro)
+
+
+
+
+
+ Allow the calling of parser hooks from SPI and cached
+ plans (Tom Lane)
+
+
+
+
+
+
+
+
+ Binary Upgrade Support
+
+
+
+
+ Add support for preservation of all relfilenodes,
+ for use during binary upgrades (Bruce Momjian)
+
+
+
+
+
+ Add support for binary upgrades to preserve pg_type
+ and pg_enum oids (Bruce Momjian)
+
+
+
+ This is needed to allow binary upgrades of user-defined composite
+ types, arrays, and enums (enumerated types).
+
+
+
+
+
+ Move tablespace data directories into their own
+ PostgreSQL version-specific subdirectory (Bruce Momjian)
+
+
+
+ This simplifies binary upgrades.
+
+
+
+
+
+
+
+
+
+
+ Contrib
+
+
+
+
+ Add multi-threaded option (
+
+
+ This allows multiple CPUs to be used for pgbench tests.
+
+
+
+
+
+ Add \shell and \setshell meta
+ commands to /contrib/pgbench
+ (Michael Paquier)
+
+
+
+
+
+ New features for /contrib/dict_xsyn
+ (Sergey Karpov)
+
+
+
+ The new options are matchorig, matchsynonyms,
+ and keepsynonyms.
+
+
+
+
+
+ Add full text dictionary /contrib/unaccent
+ (Teodor Sigaev)
+
+
+
+ This filter dictionary removes accents from tokens.
+
+
+
+
+
+ Add dblink_get_notify()
+ to /contrib/dblink (Marcus Kempe)
+
+
+
+ This allows async notifications in dblink.
+
+
+
+
+
+ Greatly increase /contrib/hstore's
+ length limit and add btree and hash abilities so GROUP
+ BY and DISTINCT operations are possible
+ (Andrew Gierth)
+
+
+
+ New functions and operators were also added.
+
+
+
+
+
+ Add /contrib/passwordcheck
+ which can check the strength of assigned passwords (Laurenz
+ Albe)
+
+
+
+ The source code of this module should be modified to implement
+ site-specific password policies.
+
+
+
+
+
+ Add query text to /contrib/auto_explain
+ output (Andrew Dunstan)
+
+
+
+
+
+ Add buffer access counters to /contrib/pg_stat_statements
+ (Itagaki Takahiro)
+
+
+
+
+
+ Update /contrib/start-scripts/linux
+ to use /proc/self/oom_adj to disable the
+ Linux
+ out-of-memory (OOM) killer (Alex
+ Hunsaker, Tom Lane)
+
+
+
+
+
+
+
diff --git a/doc/src/sgml/release-alpha.sgml b/doc/src/sgml/release-alpha.sgml
new file mode 100644
index 00000000000..3eb9f6bac69
--- /dev/null
+++ b/doc/src/sgml/release-alpha.sgml
@@ -0,0 +1,1486 @@
+
+
+
+ Release 9.0alpha4
+
+ Overview
+
+ 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.
+
+
+ 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.
+
+
+ The release notes below highlight user visible changes and new
+ features. There are normally numerous bug fixes and performance
+ improvements in every new snapshot of PostgreSQL, and it would be
+ too bulky to attempt to list them all. Note that many bug fixes are
+ also backported to stable releases of PostgreSQL, and you should be
+ using those if you are looking for bug-fix-only upgrades for your
+ current installations.
+
+
+ The release notes are cumulative over all alpha releases. Items
+ that are new in the latest alpha release
+ are emphasized.
+
+
+
+ Migration
+
+ To upgrade from any release to an alpha release or from an alpha
+ release to any other release will most likely require a
+ dump/restore upgrade procedure. It may happen that this is not
+ necessary in particular cases, but that is not verified beforehand.
+ (The server will warn you in any case when a dump/restore is
+ necessary if you attempt to use it with an old data directory.)
+ Note, however, that the dump/restore upgrade procedure is expected
+ to work for alpha releases, and problems in this area should be
+ reported.
+
+
+
+ Testing
+
+ 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
+ the
+ testing information page.
+
+
+
+ Changes
+
+ SQL Features
+
+
+
+ Disallow comments on columns of relation types
+ other than tables, views, and composite types, that is,
+ sequences and TOAST tables.
+
+
+
+
+ Adjust naming of indexes and their columns. Index
+ expression columns are now named after the FigureColname
+ result for their expressions, rather than always being
+ "pg_expression_N". Digits are appended to this name if
+ needed to make the column name unique within the index.
+ Default names for indexes and associated constraints now
+ include the column names of all their columns, not only the
+ first one as in previous practice.
+
+
+
+
+ Allow the index name to be omitted in CREATE INDEX,
+ causing the system to choose an index name the same as it
+ would do for an unnamed index constraint. A necessary
+ side-effect is to promote the word CONCURRENTLY to a more
+ reserved status; it can't be a table/column/index name
+ anymore unless quoted.
+
+
+
+
+ Improve the handling of SET CONSTRAINTS commands by
+ having them search pg_constraint before searching pg_trigger.
+ This allows saner handling of corner cases.
+
+
+
+
+ Typed table feature; this adds the CREATE TABLE
+ name OF type command.
+
+
+
+
+ Tighten integrity checks on ALTER TABLE ... RENAME
+ COLUMN in inheritance hierarchies.
+
+
+
+
+ Replace the pg_listener-based LISTEN/NOTIFY
+ mechanism with an in-memory queue. In addition, add support
+ for a "payload" string to be passed along with each notify
+ event.
+
+
+ This implementation should be significantly more
+ efficient than the old one, and is also more compatible with
+ Hot Standby usage. There is not yet any facility for HS
+ slaves to receive notifications generated on the master,
+ although such a thing is possible in future.
+
+
+
+
+ Have SELECT and CREATE TABLE AS queries return a
+ row count. While this is invisible in psql, other
+ interfaces, like libpq, make this value visible.
+
+
+
+
+ Extend the set of frame options supported for
+ window functions. This allows the frame to start from
+ CURRENT ROW (in either RANGE or ROWS mode), and it also adds
+ support for ROWS n PRECEDING and ROWS n FOLLOWING start and
+ end points.
+
+
+
+
+ Add DO statement to support execution of procedural language
+ code without having to create a function for it.
+
+
+
+
+ Support use of function argument names to identify which
+ actual arguments match which function parameters. The syntax
+ uses AS, for example funcname(value AS arg1, anothervalue AS
+ arg2).
+
+
+
+
+ Remove previously deprecated configuration
+ parameter add_missing_from. The system now always behaves as
+ though add_missing_from were off.
+
+
+
+
+ Performance and behavioral improvements in UPDATE,
+ DELETE, and SELECT FOR UPDATE/SHARE queries with joins.
+ Fix various corner cases that could have resulted in duplicated output
+ rows. Set-returning functions are now prohibited in the
+ target list of SELECT FOR UPDATE/SHARE. FOR UPDATE does not
+ propagate into a WITH query anymore.
+
+
+
+
+ Fix SELECT FOR UPDATE/SHARE in conjunction with LIMIT.
+ Previously, it could return fewer rows than the limit specified.
+
+
+
+
+ Add a WHEN clause to CREATE TRIGGER, allowing a boolean expression
+ to be checked to determine whether the trigger should be fired.
+
+
+ For BEFORE triggers this is mostly a matter of spec compliance; but
+ for AFTER triggers it can provide a noticeable performance
+ improvement, since queuing of a deferred trigger event and
+ re-fetching of the row(s) at end of statement can be
+ short-circuited if the trigger does not need to be fired.
+
+
+
+
+ Add exclusion constraints, which generalize the concept of
+ uniqueness to support any indexable commutative operator, not just
+ equality. Two rows violate the exclusion constraint if
+ "row1.col OP row2.col" is TRUE for each of the columns in
+ the constraint.
+
+
+
+
+ Support ORDER BY within aggregate function calls, at long last
+ providing a non-kluge method for controlling the order in which
+ values are fed to an aggregate function. At the same time eliminate
+ the old implementation restriction that DISTINCT was only supported
+ for single-argument aggregates.
+
+
+ Behavioral change: formerly, agg(DISTINCT x) dropped null values of
+ x unconditionally. Now, it does so only if the aggregate's transition
+ function is strict; otherwise nulls are treated as DISTINCT
+ normally would, i.e., you get one copy.
+
+
+
+
+ Add SQL-compliant triggers on columns, which fire only if
+ certain columns are named in the UPDATE's SET list.
+
+
+
+
+ Add CREATE LIKE INCLUDING COMMENTS and STORAGE, and INCLUDING
+ ALL shortcut to allow users to make an exact copy of a table including
+ all options and features.
+
+
+
+
+ Define a new, more extensible syntax for COPY options
+ in order to support additional COPY options in the future.
+
+
+
+
+ Modify the definition of window-function PARTITION
+ BY and ORDER BY clauses so that their elements are always
+ taken as simple expressions over the query's input
+ columns. This fixes a bug.
+
+
+
+
+ Fix bug with nested WITH RECURSIVE statements.
+
+
+
+
+ Add surrogate pair support for U& string and identifier
+ syntax.
+
+
+
+
+ Add Unicode escapes in E'...' strings.
+
+
+
+
+ DROP COLUMN and DROP CONSTRAINT now support an IF EXISTS clause so
+ that users can avoid fatal errors when running repeatable scripts.
+
+
+
+
+ UNIQUE constraints can now be DEFERRABLE. This is primarily useful
+ for incremental updates of numerical keys, e.g. "ID = ID +
+ 1"
+
+
+
+
+ Allow parentheses around the query expression that follows a WITH
+ clause.
+
+
+
+
+ INFORMATION_SCHEMA, a catalog of standard views of database
+ objects, has been updated to the SQL:2008 standard.
+
+
+
+
+ Change character_octet_length to more sensible values in
+ INFORMATION_SCHEMA.
+
+
+
+
+ Allow * as parameter for FORCE QUOTE for COPY CSV, so that all
+ columns will be quoted.
+
+
+
+
+
+ Performance
+
+
+
+ Support "x IS NOT NULL" clauses as index-scan
+ conditions.
+
+
+
+
+ When estimating the selectivity of an inequality
+ "column > constant" or "column < constant", and the
+ comparison value is in the first or last histogram bin or
+ outside the histogram entirely, try to fetch the actual
+ column min or max value using an index scan (if there is an
+ index on the column). If successful, replace the lower or
+ upper histogram bound with that value before carrying on with
+ the estimate. This limits the estimation error caused by
+ moving min/max values when the comparison value is close to
+ the min or max.
+
+
+
+
+ Generic implementation of red-black binary tree.
+ For now, only GIN uses it during index creation. Using
+ self-balanced tree greatly speeds up index creation in corner
+ cases with preordered data.
+
+
+
+
+ Allow rewriting forms of ALTER TABLE to skip WAL
+ logging.
+
+
+
+
+ Speed up INFORMATION_SCHEMA's privilege views.
+
+
+
+
+ Make TRUNCATE do truncate-in-place when processing
+ a relation that was created or previously truncated in the
+ current (sub)transaction.
+
+
+
+
+ Implement "join removal" for cases where the inner side
+ of a left join is unique and is not referenced above the join. This should
+ speed up many ORM-generated and reporting tool queries.
+
+
+
+
+ Remove the use of the flat files pg_auth and
+ pg_database in order to improve performance. (Warning: pgbouncer
+ and possibly other tools currently suggest referring to the pg_auth
+ file for its user database. Such schemes will no longer work.)
+
+
+
+
+ EXPLAIN allows output of plans in XML, JSON, or YAML format for automated
+ processing of explain plans by analysis or visualization tools.
+
+
+
+
+ EXPLAIN now supports the use of generic options in EXPLAIN ( option
+ value, ... ) format, which permits the creation of additional
+ EXPLAIN options.
+
+
+
+
+ ALTER TABLE ... ALTER COLUMN ... SET STATISTICS DISTINCT allows
+ users to manually tweak the number of distinct values estimated for
+ a column, to fix cases where ANALYZE estimates are incorrect.
+
+
+
+
+ Make GEQO's planning deterministic by having it start from a
+ predictable random number seed each time.
+
+
+
+
+ Rewrite GEQO's gimme_tree function so that it always finds a legal
+ join sequence. Previously, it could have failed to produce a plan
+ in some cases.
+
+
+
+
+ Tweak TOAST code so that columns marked with MAIN storage strategy
+ are not forced out-of-line unless that is necessary to make the row
+ fit on a page. Previously, they were forced out-of-line if needed
+ to get the row down to the default target size (1/4th page).
+
+
+
+
+ Simplify the forms foo <> true and foo <> false to foo
+ = false and foo = true during query optimization.
+
+
+
+
+ Avoid per-send() system calls to manage SIGPIPE in libpq, if the
+ platform provides either sockopt(SO_NOSIGPIPE) or the MSG_NOSIGNAL
+ flag to send().
+
+
+
+
+
+ Administration and Monitoring
+
+
+
+ Add the ability to store inheritance-tree
+ statistics in pg_statistic, and teach ANALYZE to compute such
+ stats for tables that have subclasses.
+
+
+
+
+ Revise pgstat's tracking of tuple changes to
+ improve the reliability of decisions about when to
+ auto-analyze. The previous code depended on n_live_tuples +
+ n_dead_tuples - last_anl_tuples, where all three of these
+ numbers could be bad estimates from ANALYZE itself. Even
+ worse, in the presence of a steady flow of HOT updates and
+ matching HOT-tuple reclamations, auto-analyze might never
+ trigger at all, even if all three numbers are exactly right,
+ because n_dead_tuples could hold steady.
+
+
+
+
+ Support ALTER TABLESPACE name SET/RESET (
+ tablespace_options ), currently supporting seq_page_cost and
+ random_page_cost as parameters.
+
+
+
+
+ New faster implementation of VACUUM FULL. The old
+ idiom of using CLUSTER instead of VACUUM FULL for speed is
+ now obsolete.
+
+
+
+
+ Add buffer access counters to
+ pg_stat_statements.
+
+
+
+
+ Add some simple support and documentation for using
+ process-specific oom_adj settings to prevent the postmaster
+ from being OOM-killed on Linux systems.
+
+
+
+
+ Place tablespace directories in their own
+ subdirectory so pg_migrator can upgrade clusters without
+ renaming the tablespace directories.
+
+
+
+
+ Introduce Streaming Replication.
+
+
+
+
+ Add pg_table_size() and pg_indexes_size() to
+ provide more user-friendly wrappers around the
+ pg_relation_size() function.
+
+
+
+
+ Add pg_stat_reset_shared('bgwriter') to reset the
+ cluster-wide shared statistics of the bgwriter.
+
+
+
+
+ Replace ALTER TABLE ... SET STATISTICS DISTINCT
+ with a more general mechanism. Attributes can now have
+ options, just as relations and tablespaces do, and the
+ reloptions code is used to parse, validate, and store
+ them.
+
+
+
+
+ Fix longstanding gripe that we check for
+ 0000000001.history at start of archive recovery, even when we
+ know it is never present.
+
+
+
+
+ Make standby server continuously retry restoring
+ the next WAL segment with restore_command, if the connection
+ to the primary server is lost. This ensures that the standby
+ can recover automatically, if the connection is lost for a
+ long time and standby falls behind so much that the required
+ WAL segments have been archived and deleted in the
+ master.
+
+
+ This also makes standby_mode useful without
+ streaming replication; the server will keep retrying
+ restore_command every few seconds until the trigger file is
+ found. That's the same basic functionality pg_standby
+ offers, but without the bells and whistles.
+
+
+
+
+ Add functions to reset the statistics counter for a
+ single table/index or a single function.
+
+
+
+
+ Augment EXPLAIN output with more details on Hash
+ nodes.
+
+
+
+
+ Reindexing shared system catalogs is now fully
+ transactional and crash-safe.
+
+
+
+
+ Allow read-only connections during recovery, also
+ known as Hot Standby. This provides a built-in master-slave
+ replication solution.
+
+
+
+
+ Provide a parenthesized-options syntax for VACUUM, analogous to
+ that recently adopted for EXPLAIN. This will allow additional
+ options to be implemented in future without having to make them
+ fully-reserved keywords. The old syntax remains available for
+ existing options, however.
+
+
+
+
+ Add support for an application_name parameter, which is displayed
+ in pg_stat_activity and recorded in log entries.
+
+
+
+
+ Fix longstanding problems in VACUUM caused by untimely
+ interruptions.
+
+
+
+
+ Add YAML to list of EXPLAIN formats.
+
+
+
+
+ Add an EXPLAIN (BUFFERS) option to show buffer-usage statistics.
+
+
+
+
+ Add a hook to let loadable modules get control at ProcessUtility
+ execution, and use it to extend contrib/pg_stat_statements to track
+ utility commands.
+
+
+
+
+ Add a Boolean server configuration parameter
+ "bonjour" to control whether a Bonjour-enabled
+ build actually attempts to advertise itself via Bonjour.
+
+
+
+
+ When reloading postgresql.conf, log what parameters actually
+ changed.
+
+
+
+
+ Make it possibly to specify server configuration parameters
+ per user-database combination. Add a \drds command to psql to
+ display the settings.
+
+
+
+
+ Allow the collection of statistics on sequences.
+
+
+
+
+ Increase the maximum value of extra_float_digits to
+ 3, and have pg_dump use that value when the backend is new
+ enough to allow it, because it is possible to need 3 extra
+ digits for float4 values (but not for float8 values).
+
+
+
+
+ Add the ability to include the SQLSTATE error code of any error
+ messages in the PostgreSQL activity log with the new
+ log_line_prefix placeholder %e.
+
+
+
+
+ Show the exact value being complained of in
+ unique-constraint-violation error messages, including unique-index
+ build failures.
+
+
+
+
+
+ Security
+
+
+
+ Add support for RADIUS authentication.
+
+
+
+
+ When querying a table with child tables, do not check permissions
+ on the child tables, only on the parent table. The old behavior was
+ found to be useless and confusing in virtually all cases, and also
+ contrary to the SQL standard.
+
+
+
+
+ Add a hook to CREATE/ALTER ROLE to allow an external module to
+ check the strength of database passwords, and create a sample
+ implementation of such a hook as a new contrib module
+ "passwordcheck".
+
+
+
+
+ Add large object access control.
+
+
+
+
+ Allow LDAP authentication to operate in search+bind
+ mode, meaning it does a search for the user in the directory
+ first, and then binds with the DN found for this user. This
+ allows for LDAP logins in scenarios where the DN of the user
+ cannot be determined simply by prefix and suffix, such as the
+ case where different users are located in different
+ containers. The old way of authentication can be
+ significantly faster, so it's kept as an option.
+
+
+
+
+ Add ALTER DEFAULT PRIVILEGES command, which allows
+ users to adjust the privileges that will be applied to
+ subsequently-created objects.
+
+
+
+
+ Add GRANT/REVOKE ON ALL TABLES/SEQUENCES/FUNCTIONS IN SCHEMA.
+ This makes it easier to manage permissions on database objects.
+
+
+
+
+ Support "samehost" and "samenet" specifications
+ in pg_hba.conf. This allows users with dynamic server addresses to run
+ PostgreSQL without frequently modifying pg_hba.conf.
+
+
+
+
+ New has_sequence_privilege() functions allow you to check sequence
+ privileges for a given ROLE.
+
+
+
+
+
+ Built-In Functions
+
+
+
+ Fix 3-parameter form of bit substring() to throw
+ error for negative length, as required by SQL
+ standard.
+
+
+
+
+ Add get_bit/set_bit functions for bit strings,
+ paralleling those for bytea, and implement OVERLAY() for bit
+ strings and bytea.
+
+
+
+
+ Add string_agg aggregate functions. The
+ one-argument version concatenates the input values into a
+ string. The two-argument version also does the same thing,
+ but inserts delimiters between elements.
+
+
+
+
+ Honor to_char() "FM" specification in YYY, YY, and
+ Y; it was already honored by YYYY.
+
+
+
+
+ Remove configuration parameter regex_flavor. It is now always
+ "advanced".
+
+
+
+
+ Teach the regular expression functions to do case-insensitive
+ matching and locale-dependent character classification properly
+ when the database encoding is UTF8. This previously only worked
+ correctly for single-byte encodings. It is still broken for other
+ multibyte encodings.
+
+
+
+
+ Support POSIX-compatible interpretation of ? as well as {m,n}
+ and related constructs in SIMILAR TO, per SQL:2008.
+
+
+
+
+ The to_char() formatting functions now supports EEEE (scientific
+ notation).
+
+
+
+
+ Use floor() not rint() when reducing precision of fractional
+ seconds in timestamp_trunc, timestamptz_trunc, and interval_trunc()
+ for the float-datetime case. This improves accuracy of time
+ calculations.
+
+
+
+
+ Fix ancient bug in handling of to_char() modifier 'TH', when used
+ with HH.
+
+
+
+
+
+ Data Types
+
+
+
+ Allow enums to be created with zero labels, for use
+ during binary upgrade.
+
+
+
+
+ When doing "ARRAY[...]::domain", where domain is a domain
+ over an array type, we need to check domain constraints. Regression
+ introduced in 8.4.
+
+
+
+
+ Fix integer-to-bit-string conversions to handle the first
+ fractional byte correctly when the output bit width is wider than
+ the given integer by something other than a multiple of 8 bits.
+
+
+
+
+ Fix encoding handling in binary input function of xml type.
+
+
+
+
+ Tighten binary receive functions so that they reject values
+ that the text input functions don't accept either.
+
+
+
+
+ New hex-string input and output format options for type bytea. Hex
+ output format is enabled by default, which is an incompatible
+ change. See the new bytea_output parameter if you need to restore
+ compatibility.
+
+
+
+
+ Adds prefix support for text search synonym dictionary, allowing
+ creation of synonyms on partial matches.
+
+
+
+
+
+ Server Tools
+
+
+
+ initdb now selects the encoding SQL_ASCII when the locale specifies
+ US-ASCII. This case previously failed.
+
+
+
+
+ Add init[db] option to pg_ctl.
+
+
+
+
+ It is now reasonably safe to use pg_ctl to start
+ the postmaster from a boot-time script.
+
+
+
+
+ pg_dump/pg_restore --clean now drops large objects.
+
+
+
+
+ Modify parallel pg_restore ordering logic to avoid a potential
+ O(N^2) slowdown for some complex databases.
+
+
+
+
+
+ libpq
+
+
+
+ Add user-specific .pg_service.conf file.
+
+
+
+
+ Add new escaping functions PQescapeLiteral and
+ PQescapeIdentifier.
+
+
+
+
+ Introduce two new libpq connection functions,
+ PQconnectdbParams and PQconnectStartParams, which are
+ analogous to PQconnectdb and PQconnectStart respectively, but
+ accept two NULL-terminated arrays, keywords and values,
+ rather than conninfo strings. This avoids the need to build
+ the conninfo string in cases where it might be inconvenient
+ to do so.
+
+
+
+
+ Throw error when a specified connection service name is not
+ found in pg_service.conf, instead of ignoring it.
+
+
+
+
+ Make libpq reject non-numeric and out-of-range port numbers with a
+ suitable error message.
+
+
+
+
+
+ psql
+
+
+
+ Allow psql variables to be interpolated with
+ literal or identifier escaping.
+
+
+
+
+ In psql, show view definition only with \d+, not with \d.
+
+
+
+
+ In psql, ignore UTF-8-encoded Unicode byte-order mark at the
+ beginning of a file if the client encoding is UTF-8.
+
+
+
+
+ Improve psql's tabular display of wrapped-around data by inserting
+ markers in the formerly-always-blank columns just to left and right
+ of the data. "pset linestyle old-ascii" is added to make
+ the previous behavior available if anyone really wants it.
+
+
+
+
+ Simplify psql's new linestyle behavior to default to
+ linestyle=ascii all the time, rather than hoping we can tell
+ whether the terminal supports UTF-8 characters.
+
+
+
+
+ Implement significantly saner behavior when two or
+ more psql sessions overlap in their use of the history file.
+
+
+
+
+ Add "pset linestyle ascii/unicode" option to psql,
+ allowing our traditional ASCII-art style of table output to
+ be upgraded to use Unicode box drawing characters if
+ desired.
+
+
+
+
+ Have \d show child tables that inherit from the specified parent
+
+
+
+
+ psql now shows the index methods in \di
+
+
+
+
+
+
+ Procedural Languages
+
+ PL/pgSQL
+
+
+
+ Add "USING expressions" option to PL/pgSQL's OPEN
+ cursor FOR EXECUTE.
+
+
+
+
+ PL/pgSQL is installed by default.
+
+
+
+
+ Remove PL/pgSQL's RENAME declaration, which has
+ bizarre and mostly nonfunctional behavior, and is so little
+ used that no one has been interested in fixing it. To ensure
+ that possible uses are covered, remove the ALIAS declaration's
+ arbitrary restriction that only $n identifiers can be
+ aliased.
+
+
+
+
+ The PL/pgSQL parser and scanner were reworked to behave much more
+ sanely:
+
+
+ A variable reference will only be recognized where it can validly
+ go, ie, a place where a column value or parameter would be legal,
+ instead of the former behavior that would replace any textual match
+ including table names and column aliases (leading to syntax errors
+ later on).
+
+
+ When a name could refer either to a PL/pgSQL variable or a
+ table column, PL/pgSQL formerly always assumed the variable was
+ meant, sometimes resulting in surprising behavior. Now, PL/pgSQL
+ can assume the variable is meant, or assume the table column is
+ meant, or throw an error in ambiguous cases. For safety the default
+ is to throw error. To configure this see the PL/pgSQL documentation.
+
+
+ Error reporting is much nicer: it no longer shows edited
+ versions of statements that look significantly different from what
+ you wrote.
+
+
+ Note that this change affects the set of keywords that are
+ reserved in PL/pgSQL (i.e., cannot be the name of a PL/pgSQL
+ variable). Now, all keywords shown as reserved in Appendix C are reserved for
+ PL/pgSQL purposes as well. However, many PL/pgSQL-only keywords
+ that were formerly treated as reserved no longer are. As in regular
+ SQL, you can double-quote a variable's name if you want to use a
+ name that conflicts with a reserved keyword.
+
+
+
+
+ PL/pgSQL IN parameters now accept value assignments.
+
+
+
+
+ Allow cursor commands MOVE FORWARD n, MOVE BACKWARD n,
+ MOVE FORWARD ALL, MOVE BACKWARD ALL in PL/pgSQL.
+
+
+
+
+ PL/pgSQL functions can now better cope with row types
+ containing dropped columns.
+
+
+
+
+
+
+ PL/Perl
+
+
+
+ Add utility functions to PL/Perl: quote_literal,
+ quote_nullable, quote_ident, encode_bytea, decode_bytea,
+ looks_like_number, encode_array_literal,
+ encode_array_constructor.
+
+
+
+
+ Add plperl.on_plperl_init, plperl.on_plperlu_init,
+ and plperl.on_init settings for startup code.
+
+
+
+
+ Allow (ineffective) use of "require". If the
+ required module is not already loaded then it dies. So "use
+ strict;" now works in PL/Perl.
+
+
+
+
+ Pre-load the feature module if Perl >= 5.10.
+ So "use feature :5.10;" now works in PL/Perl.
+
+
+
+
+ Stored procedure subs are now given names. The
+ names are not visible in ordinary use, but they make tools
+ like Devel::NYTProf and Devel::Cover much more
+ useful.
+
+
+
+
+ Handle END blocks in PL/Perl.
+
+
+
+
+ Clean up package namespace use and use of Safe.
+
+
+
+
+ Change log level of Perl warnings from NOTICE to
+ WARNING.
+
+
+
+
+ Add support for anonymous code blocks (DO blocks) to PL/Perl.
+
+
+
+
+ Improve error context reporting in PL/Perl, for
+ easier debugging.
+
+
+
+
+ Convert a Perl array to a PostgreSQL array when returned by
+ set-returning functions as well as non-SRFs.
+
+
+
+
+
+
+ PL/Python
+
+
+
+ Improved printing of Python exceptions in
+ PL/Python.
+
+
+
+
+ Add PL/Python DO handler.
+
+
+
+
+ Support arrays as parameters and return values of PL/Python
+ functions.
+
+
+
+
+ Add Python 3 support to PL/Python. It behaves more or less
+ unchanged compared to Python 2, but the new language variant is
+ called plpython3u.
+
+
+
+
+ Fix/improve bytea and boolean support in PL/Python. Data type
+ conversion into and out of PL/Python previously went through
+ an intermediate string representation, which caused various
+ discrepancies especially with bytea and boolean data. This is
+ now fixed by converting the values directly.
+
+
+
+
+ PL/Python now accepts Unicode objects where it previously
+ only accepted string objects (for example, as return
+ value). Unicode objects are converted to the PostgreSQL
+ server encoding as necessary.
+
+
+
+
+ Improve error context reporting in PL/Python, for easier
+ debugging.
+
+
+
+
+ Greatly expand the regression testing for PL/Python.
+
+
+
+
+
+
+
+ Additional Supplied Modules
+
+
+
+ Add query text to auto_explain output.
+
+
+
+
+ Add \shell and \setshell meta commands to pgbench.
+
+
+ \shell runs an external shell command. \setshell
+ does the same and assigns the result to a variable.
+
+
+
+
+ Multiple improvements in contrib/hstore, including
+ raising limits on keys and values, conversions to and from
+ records and arrays, and support for GROUP BY and DISTINCT.
+
+
+
+
+ pgbench is now multi-threaded, allowing it to use multiple CPU's
+ for its client connections, and to do more realistic workload
+ testing.
+
+
+
+
+ Added the ability to retrieve asynchronous notifications using
+ dblink, via the addition of the function dblink_get_notify().
+
+
+
+
+ Added matchorig, matchsynonyms, and keepsynonyms options to
+ contrib/dict_xsyn.
+
+
+
+
+ Added contrib/unaccent.
+
+
+
+
+
+ ECPG
+
+
+
+ Add sqlda support in both native and compatibility
+ mode.
+
+
+
+
+ Fix SQL3 type return value: For non-SQL3 types ECPG
+ used to return -OID. This will break if there are enough OIDs
+ to fill the namespace. Therefore we play it safe and return
+ 0 if there is no OID->SQL3 type mapping available.
+
+
+
+
+ Make char the default sqlda type.
+
+
+
+
+ Add DESCRIBE [OUTPUT] statement.
+
+
+
+
+ Add out-of-scope cursor support to native mode.
+
+
+
+
+ Refactor ECPG grammar so that it uses the core grammar's
+ unreserved_keyword list, minus a few specific words that have to be
+ treated specially. This de-reserves a number of words in ECPG.
+
+
+
+
+ Added dynamic cursor names to ECPG.
+
+
+
+
+ Add ECPG function that returns the current transaction status.
+
+
+
+
+ Make ECPG more robust against applications freeing strings.
+
+
+
+
+ ECPG now includes a STRING datatype for Informix compatibility
+ mode.
+
+
+
+
+
+ Ports
+
+
+
+ Add basic build support for Visual Studio 2008,
+ without resorting to generating the build files for 2005 and
+ then converting them.
+
+
+
+
+ Added support for 64-bit Windows platforms.
+
+
+
+
+ Disable triggering failover with a signal in pg_standby on Windows.
+ It never really worked before anyway.
+
+
+
+
+ Change the WIN32 API version to be 5.01 (Windows XP), to
+ bring in the proper IPv6 headers in newer SDKs.
+
+
+
+
+ Write to the Windows eventlog in UTF-16, converting the
+ message encoding as necessary.
+
+
+
+
+ Replace use of the long-deprecated Bonjour API
+ DNSServiceRegistrationCreate with the not-so-deprecated
+ DNSServiceRegister. The new code will fail on Mac OS X
+ releases before 10.3.
+
+
+
+
+ Reserve the shared memory region during backend startup on Windows,
+ so that memory allocated by starting third party DLLs doesn't end
+ up conflicting with it. Hopefully this solves the long-time issue
+ with "could not reattach to shared memory" errors on
+ Win32.
+
+
+
+
+ Add s_lock support for SuperH architecture (not well tested).
+
+
+
+
+
+ Source Code, Build Options
+
+
+
+ Improve PGXS makefile system to allow the module's
+ makefile to specify where to install DATA and DOCS files.
+ This is mainly intended to allow versioned installation, eg,
+ install into contrib/fooM.N/ rather than directly into
+ contrib/.
+
+
+
+
+ Get rid of the need for manual maintenance of the
+ initial contents of pg_attribute, by having genbki.pl derive
+ the information from the various catalog header files. This
+ greatly simplifies modification of the "bootstrapped"
+ catalogs. This patch finally kills genbki.sh and
+ Gen_fmgrtab.sh; we now rely entirely on Perl scripts for
+ those build steps. To avoid creating a Perl build dependency
+ where there was not one before, they will be built and
+ shipped in tarballs.
+
+
+
+
+ Move the default configuration for the MSVC build
+ system to config_default.pl, and allow using config.pl to
+ override the defaults.
+
+
+
+
+ Make configure check the version of Perl we're
+ building with, and reject versions < 5.8.
+
+
+
+
+ Remove all support for working around on systems
+ that don't provide a working 64-bit integer type.
+
+
+
+
+ Add new make targets "world", "install-world" and
+ "installcheck-world" to build, install and check just about
+ everything. In addition to everything built installed and
+ tested by all, install and installcheck targets, these build
+ HTML documentation, build and test contrib, and test
+ procedural languages and ECPG.
+
+
+
+
+ configure --enable-thread-safety is now the default (but can still
+ be turned off).
+
+
+
+
+ Fix inclusions of readline/editline header files so that we
+ only attempt to #include the version of history.h that is in
+ the same directory as the readline.h we are using. This
+ avoids problems in some scenarios where both readline and
+ editline are installed.
+
+
+
+
+ Derived files that are shipped in the distribution used to be
+ built in the source directory even for out-of-tree
+ builds. They are now built in the build tree. This
+ should be more convenient for certain developers' workflows.
+
+
+
+
+ Functions which conflict with C++ reserved words have been renamed,
+ making backend header files now safe to use with C++ libraries.
+
+
+
+
+ Add man pages for SPI functions.
+
+
+
+
+ Upgrade to Autoconf 2.63 (not relevant to users of distribution
+ tarballs).
+
+
+
+
+ Minimum version of Flex is now 2.5.31, to support reentrant
+ scanners (not relevant to users of distribution tarballs).
+
+
+
+
+ Documentation build rules have been improved. The generated
+ documentation files are now shipped "loose", not in
+ sub-tarballs.
+
+
+
+
+ New toolchain to generate man pages. From now on, the man pages
+ will be current in every release.
+
+
+
+
+ Code-coverage testing support now extends to the entire source
+ tree, not only src/backend/.
+
+
+
+
+ Make the core scanner re-entrant, along with additional fixes that
+ will let it be used directly by PL/pgSQL.
+
+
+
+
+
+