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 non-synchronous streaming log shipping (Andres Freund)
472 Allow much faster fail-over to a standby server (Simon Riggs)
478 Add the last checkpoint's redo location to pg_controldata's output
483 This information is useful for determining the WAL files needed for
490 Allow tooling like pg_receivexlog to run on computers with different
491 architectures (Heikki Linnakangas)
497 Have pg_basebackup --write-recovery-conf output a minimal
498 recovery.conf (Zoltán Böszörményi, Magnus Hagander)
502 This simplifies setting up a standby server.
508 Allow pg_receivexlog and pg_basebackup -X to handle streaming
509 timeline switches (Heikki Linnakangas)
515 Add wal_receiver_timeout parameter to control the WAL receiver
516 timeout (Amit Kapila)
520 This allows more rapid detection of connection failure. No longer set
521 wal_receiver_status_interval?
527 Rename replication_timeout to wal_sender_timeout (Amit Kapila)
531 BACKWARD COMPATIBILITY
532 This setting controls the WAL sender timeout.
539 <title>Write-Ahead Log (WAL)</title>
545 Store WAL in a continuous stream, rather than skipping the last
546 16MB segment every 4GB (Heikki Linnakangas) BACKWARD COMPATIBLE BREAK
552 Restructure WAL files to better handle timeline changes during
553 recovery (Heikki Linnakangas)
559 Restructure WAL files to use a more compact storage format (Heikki Linnakangas)
570 <title>Queries</title>
576 Implement SQL-standard LATERAL for FROM-clause subqueries and
577 function calls (Tom Lane)
581 This is useful in allowing FROM subqueries and functions to reference
582 output from tables in the FROM clause. The LATERAL keyword is optional
589 Add support for piping COPY and psql \copy to/from an external program (Etsuro
596 Improve query string error location reporting (Tom Lane)
600 Only CREATE SCHEMA ... IF NOT EXISTS? If so, remove it.
609 <title>Object Manipulation</title>
615 Add support to event triggers (Dimitri Fontaine, Tom Lane)
619 This allows C functions to be called when specific commands are run.
625 Allow a multi-row VALUES clause in rules to reference OLD/NEW (Tom Lane)
631 Add CREATE SCHEMA ... IF NOT EXIST clause (Fabrízio de
638 Throw an error if expiring tuple is again updated or deleted (Kevin Grittner)
645 Have DROP OWNED only remove user-matching GRANTs on shared objects,
646 e.g. databases, tablespaces (Álvaro Herrera)
650 Previously it tried to remove such objects, leading to an error.
656 Have REASSIGN OWNED also change ownership of shared objects (Álvaro
664 <title><link linkend="SQL-CREATETABLE"><command>CREATE TABLE</></link></title>
670 No longer output messages about implicit index and sequence creation (Robert Haas)
674 These messages now appear with DEBUG1-level output.
680 Allow CREATE TABLE IF NOT EXIST to succeed for a non-existent schema
685 Previously, it threw an error if the schema did not exist.
694 <title>Constraints</title>
700 Change ON UPDATE SET NULL/SET DEFAULT foreign key actions to affect
701 all referenced columns, not just those referenced in the UPDATE
706 Previously only columns referenced in the UPDATE were set to null or DEFAULT.
707 BACKWARD COMPATIBILITY CHANGE
713 Provide clients with constraint violation details as separate fields
718 This allows clients to retrieve table, column, data type, or constraint
719 name error details. Previously such information had to be extracted from
720 error strings. Client language support is required to access these
727 Internally store default foreign key matches (non-FULL, non-PARTIAL) as "simple" (Tom Lane)
731 These were previously stored as "&unspecified&".
732 This changes the value stored in system column
733 pg_constraint.confmatchtype. BACKWARD COMPATIBILITY CHANGE
742 <title><command>ALTER</></title>
748 Add the ALTER TYPE ... IF NOT EXISTS clause when adding enumerated type labels (Andrew
753 This is useful for conditional label creation in transaction blocks.
759 Add ALTER ROLE ALL SET to add settings to all users (Peter Eisentraut)
763 This allows settings to apply to all users in all databases. ALTER
764 DATABASE SET already allowed addition of settings for all users in a
765 single database. postgresql.conf has a similar effect.
771 Add support for ALTER RULE ... RENAME (Ali Dar)
780 <title><link linkend="rules-views"><command>VIEWs</></link></title>
786 Add a materialized view relations (Kevin Grittner)
790 Unlike ordinary views, where the base tables are read on every access,
791 materialized views create physical tables at creation or refresh time.
792 Access to the materialized view reads from these materialized physical
793 tables. There is no facility for incrementally refreshing materialized
794 views or auto-accessing them via base table access.
800 Make simple views auto-updatable (Dean Rasheed)
804 INSTEAD rules are still available for complex views.
810 Allow views and rules to handle cases where referenced tables are
811 renamed, or columns are renamed, added, or dropped (Tom Lane)
812 HOW DOES IT HANDLE A DROPPED REFERENCED COLUMN?
818 Add CREATE RECURSIVE VIEW syntax (Peter Eisentraut)
822 Internally this is translated into CREATE VIEW ... WITH RECURSIVE.
828 When converting a table to a view, remove its system columns (Tom Lane)
840 <title>Data Types</title>
846 Increase the maximum length of large objects from 2GB to 4TB (Nozomi
851 This change includes new libpq and server-side 64-bit-enabled functions.
857 Allow text timezone designations, e.g. "America/Chicago" when using the
858 ISO "T" timestamptz format (Bruce Momjian)
871 Add operators and functions to extract values from JSON data strings
878 Allow JSON data strings to be converted into records (Andrew Dunstan)
884 Add functions to convert values, records, and hstore data to JSON (Andrew Dunstan)
896 <title>Functions</title>
902 Add array_remove() and array_replace() functions (Marco Nenciarini, Gabriele Bartolini)
908 Allow concat() and format() to properly expand VARIADIC-labeled
909 arguments (Pavel Stehule)
915 Improve format() to handle field width and left/right alignment
922 Have to_char(), to_date(), and to_timestamp() properly handle
923 negative century designations (CC) (Bruce Momjian)
927 Previously the behavior was either wrong or inconsistent with
928 positive/AD handling, e.g. format mask 'IYYY-IW-DY'.
934 Have to_date() and to_timestamp() return proper results when mixing
935 ISO and Gregorian week/day designations (Bruce Momjian)
941 Cause pg_get_viewdef() to default to wrapping after every SELECT
942 target list and FROM entry (Marko Tiikkaja)
946 This causes view output, like from pg_dump, to be more narrow.
952 Have map_sql_value_to_xml_value() properly expand domains (Pavel
959 Force cached functions to be replanned if the search_path changes (Tom Lane)
963 Previously functions already run in the current session ignored
974 <title>Server-Side Languages</title>
980 Allow SPI functions to access the number of rows processed by COPY (Pavel
988 <title><link linkend="plpgsql">PL/pgSQL</link> Server-Side Language</title>
994 Allow PL/pgSQL to use RETURN with a composite-type expressions (Asif
999 Previously RETURN could only reference composite-type variables.
1005 Allow PL/pgSQL to access the number of rows processed by COPY (Pavel
1010 The command is GET DIAGNOSTICS x = ROW_COUNT.
1016 Allow greater flexibility in where keywords can be used in PL/pgSQL (Tom Lane)
1025 <title><link linkend="plpython">PL/Python</link> Server-Side Language</title>
1031 Add PL/Python result object string handler (Peter Eisentraut)
1035 This allows plpy.debug(rv) to output something reasonable.
1041 Have PL/Python convert oid values to a proper Python numeric type (Peter Eisentraut)
1047 Handle SPIErrors raised explicitly with PL/Python's RAISE the same as
1048 as internal SPI errors (Oskari Saarenmaa and Jan Urbanski)
1059 <title>Client Applications</title>
1065 Add command-line utility pg_isready to check if the server is ready
1066 to accept connections (Phil Sorber)
1072 Support multiple --table arguments for pg_restore, clusterdb,
1073 reindexdb, and vacuumdb (Josh Kupershmidt)
1077 This is similar to the pg_dump --table support.
1083 Add -d option to pg_dumpall, pg_basebackup, pg_receivexlog to
1084 specify the connection string (Amit Kapila)
1090 Allow pg_ctl --idempotent to a 'success' return code if the requested
1091 start/stop action fails, but the cluster is already in the requested
1092 state (Peter Eisentraut)
1098 Change pg_ctl to return an error code if start fails because the
1099 server is already running (Peter Eisentraut)
1105 Add libpq function PQconninfo() to return connection information
1106 (Zoltan Boszormenyi, Magnus Hagander)
1113 <title><link linkend="APP-PSQL"><application>psql</></link></title>
1119 Adjust function cost settings so psql tab completion and pattern
1120 searching is more efficient (Tom Lane)
1126 Improve psql tab completion (Jeff Janes, Peter Eisentraut)
1132 Allow the psql --single-transaction mode to work when reading from
1133 standard input (Fabien Coelho, Robert Haas)
1137 Previously this option only worked when reading from a file.
1143 Remove psql warning when connecting to an older server (Peter Eisentraut)
1147 The warning when connecting to a newer server was retained.
1154 <title>Backslash Commands</title>
1160 Add psql \watch command to repeatedly execute commands (Will
1167 Add psql command \gset to store query results in psql variables
1174 Add SSL information to psql's \conninfo command (Alastair Turner)
1180 Add "Security" label to psql \df+ output (Jon Erdman)
1186 Allow psql \l to accept a database name pattern (Peter Eisentraut)
1192 In psql, do not allow \connect to use defaults if there is no active
1193 connection (Bruce Momjian)
1197 This might be the case if the server had crashed.
1203 Properly reset state if psql's "\g file" command failed (Tom Lane)
1207 Previously failed commands discarded output from subsequent commands.
1216 <title>Output</title>
1222 Add a 'latex-longtable' output format to psql (Bruce Momjian)
1226 Longtable allows tables to span multiple pages.
1232 Add a border=3 output mode to the psql 'latex' format (Bruce Momjian)
1238 In psql tuples-only and expanded modes, no longer output "(No rows)"
1245 In psql, no longer print an empty line for unaligned, expanded
1246 output for zero rows (Peter Eisentraut)
1257 <title><link linkend="APP-PGDUMP"><application>pg_dump</></link></title>
1263 Add pg_dump --jobs to dump in parallel when using directory
1264 output format (Joachim Wieland)
1270 Have pg_dump output functions in a predictable order (Joel Jacobson)
1276 Fix tar files emitted by pg_dump and pg_basebackup to be POSIX
1277 conformant (Brian Weaver, Tom Lane)
1283 Add -d/--dbname option to pg_dump, for consistency with other client
1284 commands (Heikki Linnakangas)
1288 The database name could already be supplied last without a flag.
1297 <title><link linkend="APP-INITDB"><application>initdb</></link></title>
1303 Have initdb fsync the newly created data directory (Jeff Davis)
1307 This can be disabled by using --nosync.
1313 Add initdb --sync-only option to sync the data directory to durable
1314 storage (Bruce Momjian)
1318 This is used by pg_upgrade.
1324 Have initdb issue a warning about placing the data directory at the
1325 top of file system mount points (Bruce Momjian)
1336 <title>Source Code</title>
1342 Add an embedded list interface (Andres Freund)
1348 Add infrastructure to better support plug-in background worker
1349 processes (Álvaro Herrera)
1355 Create a centralized timeout API (Zoltán Böszörményi)
1361 Create libpgcommon and move pg_malloc() and other functions there
1362 (Álvaro Herrera, Andres Freund)
1366 This allows libpgport to be used solely for porting code.
1372 Standardize on naming of client-side memory allocation functions (Tom Lane)
1378 Add compiler designations to indicate some ereport() and elog()
1379 calls do not return (Peter Eisentraut, Andres Freund, Tom Lane,
1386 Allow options to be passed to the regression test output comparison
1387 utility via PG_REGRESS_DIFF_OPTS (Peter Eisentraut)
1393 Add isolation tests for CREATE INDEX CONCURRENTLY (Abhijit Menon-Sen)
1399 Remove typedefs for int2/int4 as they are better represented as int16/int32 (Peter Eisentraut)
1405 Fix install-strip on Mac OS X (Peter Eisentraut)
1411 Remove configure flag --disable-shared, as it is no longer used (Bruce Momjian)
1417 Rewrite pgindent in Perl (Andrew Dunstan)
1423 Add emacs macro to match Postgres perltidy formatting (Peter
1430 Run tool to check the keyword list when the backend grammar is changed (Tom Lane)
1436 Centralize flex and bison 'make' rules (Peter Eisentraut)
1440 This is useful for pgxs authors.
1446 Add Assert() functionality to client-side code for frontend code (Andrew Dunstan)
1452 Change many internal many backend functions to return OIDs rather
1453 than void (Dimitri Fontaine)
1457 This is useful for event triggers.
1463 Invent pre-commit/pre-prepare/pre-subcommit events for transaction
1464 callbacks (Tom Lane)
1468 Loadable modules that use transaction callbacks might need modification
1469 to handle these new event types.
1475 Add function pg_identify_object() to dump an object in
1476 machine-readable format (Álvaro Herrera)
1482 Add post-ALTER-object server hooks (KaiGai Kohei)
1488 Improve ability to detect official timezone abbreviation changes
1495 Add pkg-config support libpq and ecpg libraries (Peter Eisentraut)
1501 Remove src/tool/backend, now that the content is on the Postgres
1502 wiki (Bruce Momjian)
1508 Split out WAL reading as an independent facility (Heikki
1509 Linnakangas, Andres Freund)
1515 Allow PL/Python to support platform-specific include directories (Peter Eisentraut)
1521 Allow PL/Python on OS X to build against custom versions of Python
1531 <title>Additional Modules</title>
1537 Add a Postgres foreign data wrapper contrib module (Shigeru
1538 Hanada, KaiGai Kohei)
1542 This foreign data wrapper allows writes; potentially other
1543 foreign data wrappers can now support writes.
1549 Add pg_xlogdump contrib program (Andres Freund)
1555 Add support for indexing of regular-expression searches in
1556 contrib/pg_trgm (Alexander Korotkov)
1562 Improve pg_trgm handling of multibyte characters (Tom Lane)
1568 Have oid2name, pgbench, and vacuumlo set fallback_application_name (Amit Kapila)
1574 Improve output of pg_test_timing (Bruce Momjian)
1580 Improve output of pg_test_fsync (Peter Geoghegan)
1586 Improve dblink option validator (Tom Lane)
1597 <title><link linkend="pgupgrade"><application>pg_upgrade</></link></title>
1603 Allow pg_upgrade --jobs to do parallelism (Bruce Momjian)
1607 This allows parallel schema dump/restore of databases, as well as
1608 parallel copy/link of data files per tablespace.
1614 Have pg_upgrade create unix-domain sockets in the current directory
1615 (Bruce Momjian, Tom Lane)
1619 This reduces the possibility that someone will accidentally connect
1626 Have pg_upgrade --check mode properly detect the location of
1627 non-default socket directories (Bruce Momjian, Tom Lane)
1633 Improve performance of pg_upgrade for databases with many tables (Bruce Momjian)
1639 Increase pg_upgrade logging content by showing executed command
1640 (Álvaro Herrera)
1646 Improve pg_upgrade's status display during copy/link (Bruce Momjian)
1655 <title><link linkend="pgbench"><application>pgbench</></link></title>
1661 Add --foreign-keys option to pgbench (Jeff Janes)
1665 This adds foreign key constraints to tables, for use in foreign
1666 key performance testing.
1672 Allow pgbench to aggregate performance statistics and produce output
1673 every --aggregate-interval specified seconds (Tomas Vondra)
1679 Add pg_bench --sampling-rate option to control the percentage of
1680 transactions logged (Tomas Vondra)
1686 Reduce and improve the status message output of pgbench's
1687 initialization mode (Robert Haas, Peter Eisentraut)
1693 Add pgbench -q mode to print one output line every five seconds (Tomas Vondra)
1697 Output pgbench elapsed and estimated remaining time during
1698 initialization logging (Tomas Vondra)
1704 Allow pgbench to use a larger scale factor (Greg Smith)
1715 <title>Documentation</title>
1721 Allow EPUB-format documentation to be created (Peter Eisentraut)
1727 Update FreeBSD kernel configuration documentation (Brad Davis)
1733 Improve WINDOW function documentation (Bruce Momjian, Tom Lane)
1739 Add instructions for setting up the documentation tool chain on
1740 Mac OS X (Peter Eisentraut)
1746 Improve commit_delay documentation (Peter Geoghegan)