1 <!-- doc/src/sgml/release-9.3.sgml -->
2 <!-- See header comment in release.sgml about typical markup -->
4 <sect1 id="release-9-3">
5 <title>Release 9.3</title>
8 <title>Release Date</title>
9 <simpara>2013-XX-XX, CURRENT AS OF 2013-04-20</simpara>
13 <title>Overview</title>
16 ADD HERE Major enhancements include:
19 <!-- This list duplicates items below, but without authors or details-->
22 The above items are explained in more detail in the sections below.
29 <title>Migration to Version 9.3</title>
32 A dump/restore using <link
33 linkend="APP-PG-DUMPALL"><application>pg_dumpall</></link>, or use
34 of <link linkend="pgupgrade"><application>pg_upgrade</></link>, is
35 required for those wishing to migrate data from any previous release.
39 Version 9.3 contains a number of changes that may affect compatibility
40 with previous releases. Observe the following incompatibilities:
44 <title>ADD HERE</title>
51 <title>Changes</title>
54 Below you will find a detailed account of the changes between
55 <productname>PostgreSQL</productname> 9.3 and the previous major
63 <title>Locking</title>
69 Prevent non-key-field row updates from locking foreign key rows
70 (Álvaro Herrera, Marti Raudsepp, Alexander Shulgin,
71 Noah Misch and Andres Freund)
75 This improves concurrency and reduces the probability of deadlocks.
76 UPDATEs on non-key columns use the new SELECT FOR NO KEY UPDATE lock
77 type, and foreign key checks use the new SELECT FOR KEY SHARE lock mode.
83 Add cache of local locks (Jeff Janes)
87 This speeds lock release at statement completion in transactions
88 that hold many locks; it is particularly useful for pg_dump.
97 <title>Indexes</title>
103 Add SP-GiST support for range data types (Alexander Korotkov)
109 Allow unlogged GiST indexes (Jeevan Chalke)
115 Improve concurrency of hash indexes (Robert Haas)
124 <title>Optimizer</title>
130 Improve the ability to detect indexable prefixes in regular
131 expressions (Tom Lane)
137 Collect and use histograms for range types (Alexander Korotkov)
143 Reduce optimizer overhead by discarding plans with unneeded cheaper
144 startup costs (Tom Lane)
150 Improve optimizer cost estimation for index access (Tom Lane)
159 <title>General Performance</title>
165 Add COPY FREEZE option to avoid the overhead of later marking
166 tuples as committed (Simon Riggs, Jeff Davis)
172 Improve performance of NUMERIC calculations (Kyotaro Horiguchi)
178 Improve grouping of sessions waiting for commit_delay (Peter
183 This improves the usefulness and behavior of commit_delay.
184 BACKWARD COMPATIBILITY
190 Implement a generic binary heap and use it for Merge-Append
191 operations (Abhijit Menon-Sen)
197 "Allow in-memory sorts to use their full memory allocation (Jeff Janes)
201 Users who have set work_mem based on the previous behavior should
202 revisit that setting.
208 Improve performance for transactions creating, rebuilding, or
209 dropping many relations (Jeff Janes, Tomas Vondra)
215 Improve performance of the CREATE TABLE ... ON COMMIT DELETE ROWS
216 clause by only issuing delete if the temporary table was accessed
223 Allow heap-only tuple updates on system tables (Andres Freund)
229 Have vacuum recheck visibility after it has removed expired tuples
234 This increases the chance of a page being marked as all-visible.
240 Split pgstat file in per-database and global files (Tomas Vondra)
244 This reduces the statistics management read and write overhead.
253 <title>Monitoring</title>
259 Add optional ability to checksum data pages and report corruption
260 (Simon Riggs, Jeff Davis, Greg Smith)
264 The checksum option can be set during initdb.
270 Allow pg_terminate_backend() to terminate other backends with
271 the same role (Dan Farina)
275 Previously, only superusers could terminate other sessions.
281 Allow the statistics collector to operate properly in cases where
282 the system clock goes backwards (Tom Lane)
286 Previously statistics collection would stop until the time again
287 reached the previously-stored latest time.
293 Add function to report the size of the GIN pending index insertion
298 The function is pgstatginindex() in pgstattuple.
307 <title>Authentication</title>
313 Improve LDAP error reporting and documentation (Peter Eisentraut)
319 Add support for LDAP authentication to be specified in URL format
326 Change the ssl_ciphers parameter to start with DEFAULT, rather
327 than ALL, then remove insecure ciphers (Magnus Hagander)
331 It is assumed DEFAULT is more appropriate cipher set.
337 Parse/load pg_ident.conf once, not during each connection (Amit
342 This is similar to how pg_hba.conf is processed.
351 <title>Server Settings</title>
357 Dramatically reduce System V shared memory usage (Robert Haas)
361 Instead, on Unix-like systems, mmap() is used for shared memory.
362 This eliminates the requirement of increasing System V shared
363 memory kernel parameters.
369 Allow the postmaster to listen on multiple Unix-domain sockets
374 This renames configuration parameter unix_socket_directory to
375 unix_socket_directories, which accepts a list of directories.
381 Add configuration variable lock_timeout to limit lock wait duration
382 (Zoltán Böszörményi)
388 Allow a directory of configuration files to be processed (Magnus
389 Hagander, Greg Smith, Selena Deckelmann)
393 The directory is specified as include_dir in server configuration file.
399 Increase the maximum initdb-configured value for shared_buffers
400 to 128MB (Robert Haas)
404 This is the maximum value initdb attempts to set in
405 postgresql.conf; the previous value was 32MB.
411 Require superuser privileges to set commit_delay because it
412 can now potentially delay other sessions (Simon Riggs)
413 BACKWARD COMPATIBILITY
420 Remove the external PID file on postmaster exit (Peter Eisentraut)
426 Have "session id" in log_line_prefix (%c) always output four hex
427 digits after the period (Bruce Momjian) COMPATIBILITY
438 <title>Replication and Recovery</title>
444 Allow a streaming replication standbys to follow a timeline switch (Heikki Linnakangas)
448 This allows streaming standbys to feed from newly-promoted slaves.
449 Previously slaves required access to a WAL archive directory to
456 Add SQL functions pg_backup_in_progress() and pg_backup_start_time() (Gilles Darold)
460 These functions report the status of base backups.
466 Improve performance of streaming log shipping with
467 synchronous_commit disabled (Andres Freund)
473 Allow much faster promotion of a streaming standby to primary (Simon
474 Riggs, Kyotaro Horiguchi)
480 Add the last checkpoint's redo location to pg_controldata's output
485 This information is useful for determining the WAL files needed for
492 Allow tooling like pg_receivexlog to run on computers with different
493 architectures (Heikki Linnakangas)
499 Have pg_basebackup --write-recovery-conf output a minimal
500 recovery.conf (Zoltán Böszörményi, Magnus Hagander)
504 This simplifies setting up a standby server.
510 Allow pg_receivexlog and pg_basebackup -X to handle streaming
511 timeline switches (Heikki Linnakangas)
517 Add wal_receiver_timeout parameter to control the WAL receiver
518 timeout (Amit Kapila)
522 This allows more rapid detection of connection failure. No longer set
523 wal_receiver_status_interval?
529 Rename replication_timeout to wal_sender_timeout (Amit Kapila)
533 BACKWARD COMPATIBILITY
534 This setting controls the WAL sender timeout.
541 <title>Write-Ahead Log (WAL)</title>
547 Store WAL in a continuous stream, rather than skipping the last
548 16MB segment every 4GB (Heikki Linnakangas) BACKWARD COMPATIBLE BREAK
554 Restructure WAL files to better handle timeline changes during
555 recovery (Heikki Linnakangas)
561 Restructure WAL files to use a more compact storage format (Heikki Linnakangas)
572 <title>Queries</title>
578 Implement SQL-standard LATERAL for FROM-clause subqueries and
579 function calls (Tom Lane)
583 This is useful in allowing FROM subqueries and functions to reference
584 output from tables in the FROM clause. The LATERAL keyword is optional
591 Add support for piping COPY and psql \copy to/from an external program (Etsuro
598 Improve query string error location reporting (Tom Lane)
602 Only CREATE SCHEMA ... IF NOT EXISTS? If so, remove it.
611 <title>Object Manipulation</title>
617 Add support to event triggers (Dimitri Fontaine, Tom Lane)
621 This allows C functions to be called when specific commands are run.
627 Allow a multi-row VALUES clause in rules to reference OLD/NEW (Tom Lane)
633 Add CREATE SCHEMA ... IF NOT EXIST clause (Fabrízio de
640 Throw an error if expiring tuple is again updated or deleted (Kevin Grittner)
647 Have DROP OWNED only remove user-matching GRANTs on shared objects,
648 e.g. databases, tablespaces (Álvaro Herrera)
652 Previously it tried to remove such objects, leading to an error.
658 Have REASSIGN OWNED also change ownership of shared objects (Álvaro
666 <title><link linkend="SQL-CREATETABLE"><command>CREATE TABLE</></link></title>
672 No longer output messages about implicit index and sequence creation (Robert Haas)
676 These messages now appear with DEBUG1-level output.
682 Allow CREATE TABLE IF NOT EXIST to succeed for a non-existent schema
687 Previously, it threw an error if the schema did not exist.
696 <title>Constraints</title>
702 Change ON UPDATE SET NULL/SET DEFAULT foreign key actions to affect
703 all referenced columns, not just those referenced in the UPDATE
708 Previously only columns referenced in the UPDATE were set to null or DEFAULT.
709 BACKWARD COMPATIBILITY CHANGE
715 Provide clients with constraint violation details as separate fields
720 This allows clients to retrieve table, column, data type, or constraint
721 name error details. Previously such information had to be extracted from
722 error strings. Client language support is required to access these
729 Internally store default foreign key matches (non-FULL, non-PARTIAL) as "simple" (Tom Lane)
733 These were previously stored as "&unspecified&".
734 This changes the value stored in system column
735 pg_constraint.confmatchtype. BACKWARD COMPATIBILITY CHANGE
744 <title><command>ALTER</></title>
750 Add the ALTER TYPE ... IF NOT EXISTS clause when adding enumerated type labels (Andrew
755 This is useful for conditional label creation in transaction blocks.
761 Add ALTER ROLE ALL SET to add settings to all users (Peter Eisentraut)
765 This allows settings to apply to all users in all databases. ALTER
766 DATABASE SET already allowed addition of settings for all users in a
767 single database. postgresql.conf has a similar effect.
773 Add support for ALTER RULE ... RENAME (Ali Dar)
782 <title><link linkend="rules-views"><command>VIEWs</></link></title>
788 Add a materialized view relations (Kevin Grittner)
792 Unlike ordinary views, where the base tables are read on every access,
793 materialized views create physical tables at creation or refresh time.
794 Access to the materialized view reads from these materialized physical
795 tables. There is no facility for incrementally refreshing materialized
796 views or auto-accessing them via base table access.
802 Make simple views auto-updatable (Dean Rasheed)
806 INSTEAD rules are still available for complex views.
812 Allow views and rules to handle cases where referenced tables are
813 renamed, or columns are renamed, added, or dropped (Tom Lane)
814 HOW DOES IT HANDLE A DROPPED REFERENCED COLUMN?
820 Add CREATE RECURSIVE VIEW syntax (Peter Eisentraut)
824 Internally this is translated into CREATE VIEW ... WITH RECURSIVE.
830 When converting a table to a view, remove its system columns (Tom Lane)
842 <title>Data Types</title>
848 Increase the maximum length of large objects from 2GB to 4TB (Nozomi
853 This change includes new libpq and server-side 64-bit-enabled functions.
859 Allow text timezone designations, e.g. "America/Chicago" when using the
860 ISO "T" timestamptz format (Bruce Momjian)
873 Add operators and functions to extract values from JSON data strings
880 Allow JSON data strings to be converted into records (Andrew Dunstan)
886 Add functions to convert values, records, and hstore data to JSON (Andrew Dunstan)
898 <title>Functions</title>
904 Add array_remove() and array_replace() functions (Marco Nenciarini, Gabriele Bartolini)
910 Allow concat() and format() to properly expand VARIADIC-labeled
911 arguments (Pavel Stehule)
917 Improve format() to handle field width and left/right alignment
924 Have to_char(), to_date(), and to_timestamp() properly handle
925 negative century designations (CC) (Bruce Momjian)
929 Previously the behavior was either wrong or inconsistent with
930 positive/AD handling, e.g. format mask 'IYYY-IW-DY'.
936 Have to_date() and to_timestamp() return proper results when mixing
937 ISO and Gregorian week/day designations (Bruce Momjian)
943 Cause pg_get_viewdef() to default to wrapping after every SELECT
944 target list and FROM entry (Marko Tiikkaja)
948 This causes view output, like from pg_dump, to be more narrow.
954 Have map_sql_value_to_xml_value() properly expand domains (Pavel
961 Force cached functions to be replanned if the search_path changes (Tom Lane)
965 Previously functions already run in the current session ignored
976 <title>Server-Side Languages</title>
982 Allow SPI functions to access the number of rows processed by COPY (Pavel
990 <title><link linkend="plpgsql">PL/pgSQL</link> Server-Side Language</title>
996 Allow PL/pgSQL to use RETURN with a composite-type expressions (Asif
1001 Previously RETURN could only reference composite-type variables.
1007 Allow PL/pgSQL to access the number of rows processed by COPY (Pavel
1012 The command is GET DIAGNOSTICS x = ROW_COUNT.
1018 Allow greater flexibility in where keywords can be used in PL/pgSQL (Tom Lane)
1027 <title><link linkend="plpython">PL/Python</link> Server-Side Language</title>
1033 Add PL/Python result object string handler (Peter Eisentraut)
1037 This allows plpy.debug(rv) to output something reasonable.
1043 Have PL/Python convert oid values to a proper Python numeric type (Peter Eisentraut)
1049 Handle SPIErrors raised explicitly with PL/Python's RAISE the same as
1050 as internal SPI errors (Oskari Saarenmaa and Jan Urbanski)
1061 <title>Client Applications</title>
1067 Add command-line utility pg_isready to check if the server is ready
1068 to accept connections (Phil Sorber)
1074 Support multiple --table arguments for pg_restore, clusterdb,
1075 reindexdb, and vacuumdb (Josh Kupershmidt)
1079 This is similar to the pg_dump --table support.
1085 Add -d option to pg_dumpall, pg_basebackup, pg_receivexlog to
1086 specify the connection string (Amit Kapila)
1092 Allow pg_ctl --idempotent to a 'success' return code if the requested
1093 start/stop action fails, but the cluster is already in the requested
1094 state (Peter Eisentraut)
1100 Change pg_ctl to return an error code if start fails because the
1101 server is already running (Peter Eisentraut)
1107 Add libpq function PQconninfo() to return connection information
1108 (Zoltan Boszormenyi, Magnus Hagander)
1115 <title><link linkend="APP-PSQL"><application>psql</></link></title>
1121 Adjust function cost settings so psql tab completion and pattern
1122 searching is more efficient (Tom Lane)
1128 Improve psql tab completion (Jeff Janes, Peter Eisentraut)
1134 Allow the psql --single-transaction mode to work when reading from
1135 standard input (Fabien Coelho, Robert Haas)
1139 Previously this option only worked when reading from a file.
1145 Remove psql warning when connecting to an older server (Peter Eisentraut)
1149 The warning when connecting to a newer server was retained.
1156 <title>Backslash Commands</title>
1162 Add psql \watch command to repeatedly execute commands (Will
1169 Add psql command \gset to store query results in psql variables
1176 Add SSL information to psql's \conninfo command (Alastair Turner)
1182 Add "Security" label to psql \df+ output (Jon Erdman)
1188 Allow psql \l to accept a database name pattern (Peter Eisentraut)
1194 In psql, do not allow \connect to use defaults if there is no active
1195 connection (Bruce Momjian)
1199 This might be the case if the server had crashed.
1205 Properly reset state if psql's "\g file" command failed (Tom Lane)
1209 Previously failed commands discarded output from subsequent commands.
1218 <title>Output</title>
1224 Add a 'latex-longtable' output format to psql (Bruce Momjian)
1228 Longtable allows tables to span multiple pages.
1234 Add a border=3 output mode to the psql 'latex' format (Bruce Momjian)
1240 In psql tuples-only and expanded modes, no longer output "(No rows)"
1247 In psql, no longer print an empty line for unaligned, expanded
1248 output for zero rows (Peter Eisentraut)
1259 <title><link linkend="APP-PGDUMP"><application>pg_dump</></link></title>
1265 Add pg_dump --jobs to dump in parallel when using directory
1266 output format (Joachim Wieland)
1272 Have pg_dump output functions in a predictable order (Joel Jacobson)
1278 Fix tar files emitted by pg_dump and pg_basebackup to be POSIX
1279 conformant (Brian Weaver, Tom Lane)
1285 Add -d/--dbname option to pg_dump, for consistency with other client
1286 commands (Heikki Linnakangas)
1290 The database name could already be supplied last without a flag.
1299 <title><link linkend="APP-INITDB"><application>initdb</></link></title>
1305 Have initdb fsync the newly created data directory (Jeff Davis)
1309 This can be disabled by using --nosync.
1315 Add initdb --sync-only option to sync the data directory to durable
1316 storage (Bruce Momjian)
1320 This is used by pg_upgrade.
1326 Have initdb issue a warning about placing the data directory at the
1327 top of file system mount points (Bruce Momjian)
1338 <title>Source Code</title>
1344 Add an embedded list interface (Andres Freund)
1350 Add infrastructure to better support plug-in background worker
1351 processes (Álvaro Herrera)
1357 Create a centralized timeout API (Zoltán Böszörményi)
1363 Create libpgcommon and move pg_malloc() and other functions there
1364 (Álvaro Herrera, Andres Freund)
1368 This allows libpgport to be used solely for porting code.
1374 Standardize on naming of client-side memory allocation functions (Tom Lane)
1380 Add compiler designations to indicate some ereport() and elog()
1381 calls do not return (Peter Eisentraut, Andres Freund, Tom Lane,
1388 Allow options to be passed to the regression test output comparison
1389 utility via PG_REGRESS_DIFF_OPTS (Peter Eisentraut)
1395 Add isolation tests for CREATE INDEX CONCURRENTLY (Abhijit Menon-Sen)
1401 Remove typedefs for int2/int4 as they are better represented as int16/int32 (Peter Eisentraut)
1407 Fix install-strip on Mac OS X (Peter Eisentraut)
1413 Remove configure flag --disable-shared, as it is no longer used (Bruce Momjian)
1419 Rewrite pgindent in Perl (Andrew Dunstan)
1425 Add emacs macro to match Postgres perltidy formatting (Peter
1432 Run tool to check the keyword list when the backend grammar is changed (Tom Lane)
1438 Centralize flex and bison 'make' rules (Peter Eisentraut)
1442 This is useful for pgxs authors.
1448 Add Assert() functionality to client-side code for frontend code (Andrew Dunstan)
1454 Change many internal many backend functions to return OIDs rather
1455 than void (Dimitri Fontaine)
1459 This is useful for event triggers.
1465 Invent pre-commit/pre-prepare/pre-subcommit events for transaction
1466 callbacks (Tom Lane)
1470 Loadable modules that use transaction callbacks might need modification
1471 to handle these new event types.
1477 Add function pg_identify_object() to dump an object in
1478 machine-readable format (Álvaro Herrera)
1484 Add post-ALTER-object server hooks (KaiGai Kohei)
1490 Improve ability to detect official timezone abbreviation changes
1497 Add pkg-config support libpq and ecpg libraries (Peter Eisentraut)
1503 Remove src/tool/backend, now that the content is on the Postgres
1504 wiki (Bruce Momjian)
1510 Split out WAL reading as an independent facility (Heikki
1511 Linnakangas, Andres Freund)
1517 Allow PL/Python to support platform-specific include directories (Peter Eisentraut)
1523 Allow PL/Python on OS X to build against custom versions of Python
1533 <title>Additional Modules</title>
1539 Add a Postgres foreign data wrapper contrib module (Shigeru
1540 Hanada, KaiGai Kohei)
1544 This foreign data wrapper allows writes; potentially other
1545 foreign data wrappers can now support writes.
1551 Add pg_xlogdump contrib program (Andres Freund)
1557 Add support for indexing of regular-expression searches in
1558 contrib/pg_trgm (Alexander Korotkov)
1564 Improve pg_trgm handling of multibyte characters (Tom Lane)
1570 Have oid2name, pgbench, and vacuumlo set fallback_application_name (Amit Kapila)
1576 Improve output of pg_test_timing (Bruce Momjian)
1582 Improve output of pg_test_fsync (Peter Geoghegan)
1588 Improve dblink option validator (Tom Lane)
1599 <title><link linkend="pgupgrade"><application>pg_upgrade</></link></title>
1605 Allow pg_upgrade --jobs to do parallelism (Bruce Momjian)
1609 This allows parallel schema dump/restore of databases, as well as
1610 parallel copy/link of data files per tablespace.
1616 Have pg_upgrade create unix-domain sockets in the current directory
1617 (Bruce Momjian, Tom Lane)
1621 This reduces the possibility that someone will accidentally connect
1628 Have pg_upgrade --check mode properly detect the location of
1629 non-default socket directories (Bruce Momjian, Tom Lane)
1635 Improve performance of pg_upgrade for databases with many tables (Bruce Momjian)
1641 Increase pg_upgrade logging content by showing executed command
1642 (Álvaro Herrera)
1648 Improve pg_upgrade's status display during copy/link (Bruce Momjian)
1657 <title><link linkend="pgbench"><application>pgbench</></link></title>
1663 Add --foreign-keys option to pgbench (Jeff Janes)
1667 This adds foreign key constraints to tables, for use in foreign
1668 key performance testing.
1674 Allow pgbench to aggregate performance statistics and produce output
1675 every --aggregate-interval specified seconds (Tomas Vondra)
1681 Add pg_bench --sampling-rate option to control the percentage of
1682 transactions logged (Tomas Vondra)
1688 Reduce and improve the status message output of pgbench's
1689 initialization mode (Robert Haas, Peter Eisentraut)
1695 Add pgbench -q mode to print one output line every five seconds (Tomas Vondra)
1699 Output pgbench elapsed and estimated remaining time during
1700 initialization logging (Tomas Vondra)
1706 Allow pgbench to use a larger scale factor (Greg Smith)
1717 <title>Documentation</title>
1723 Allow EPUB-format documentation to be created (Peter Eisentraut)
1729 Update FreeBSD kernel configuration documentation (Brad Davis)
1735 Improve WINDOW function documentation (Bruce Momjian, Tom Lane)
1741 Add instructions for setting up the documentation tool chain on
1742 Mac OS X (Peter Eisentraut)
1748 Improve commit_delay documentation (Peter Geoghegan)