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 (AlvaroAacute;lvaro 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 of lower and upper bounds for range types
144 Reduce optimizer overhead by discarding plans with unneeded cheaper
145 startup costs (Tom Lane)
151 Improve optimizer cost estimation for index access (Tom Lane)
160 <title>General Performance</title>
166 Add COPY FREEZE option to avoid the overhead of later marking
167 tuples as committed (Simon Riggs, Jeff Davis)
173 Improve performance of NUMERIC calculations (Kyotaro Horiguchi)
179 Use a binary heap for Merge-Append operations (Abhijit Menon-Sen)
185 Improve memory usage for in-memory sorts (Jeff Janes)
189 Users who have set work_mem based on the previous behavior should
190 revisit that setting.
196 Improve performance for transactions creating, rebuilding, or
197 dropping many relations (Jeff Janes, Tomas Vondra)
203 Improve performance of the CREATE TABLE ... ON COMMIT DELETE ROWS
204 clause by only issuing delete if the temporary table was accessed
211 Allow heap-only tuple updates on system tables (Andres Freund)
217 Have vacuum recheck visibility after it has removed expired tuples
222 This increases the chance of a page being marked as all-visible.
228 Split pgstat file in per-database and global files (Tomas Vondra)
232 This reduces the statistics management read and write overhead.
241 <title>Monitoring</title>
247 Add optional ability to checksum data pages and report corruption
248 (Simon Riggs, Jeff Davis, Greg Smith)
252 The checksum option can be set during initdb.
258 Allow pg_terminate_backend() to terminate other backends with
259 the same role (Dan Farina)
263 Previously, only superusers could terminate other sessions.
269 Allow the statistics collector to operate properly in cases where
270 the system clock goes backwards (Tom Lane)
274 Previously statistics collection would stop until the time again
275 reached the previously-stored latest time.
281 Add function to report the size of the GIN pending index insertion
286 The function is pgstatginindex() in pgstattuple.
295 <title>Authentication</title>
301 Improve LDAP error reporting and documentation (Peter Eisentraut)
307 Add support for LDAP authentication to be specified in URL format
314 Change the ssl_ciphers parameter to start with DEFAULT, rather
315 than ALL, then remove insecure ciphers (Magnus Hagander)
319 It is assumed DEFAULT is more appropriate cipher set.
325 Parse/load pg_ident.conf once, not during each connection (Amit
330 This is similar to how pg_hba.conf is processed.
339 <title>Server Settings</title>
345 Dramatically reduce System V shared memory usage (Robert Haas)
349 Instead, on Unix-like systems, mmap() is used for shared memory.
350 This eliminates the requirement of increasing System V shared
351 memory kernel parameters.
357 Allow the postmaster to listen on multiple Unix-domain sockets
362 This renames configuration parameter unix_socket_directory to
363 unix_socket_directories, which accepts a list of directories.
369 Add configuration variable lock_timeout to limit lock wait duration
370 (Zoltán Böszörményi)
376 Allow a directory of configuration files to be processed (Magnus
377 Hagander, Greg Smith, Selena Deckelmann)
381 The directory is specified as include_dir in server configuration file.
387 Increase the maximum initdb-configured value for shared_buffers
388 to 128MB (Robert Haas)
392 This is the maximum value initdb attempts to set in
393 postgresql.conf; the previous value was 32MB.
399 Improve grouping of sessions waiting for commit_delay (Peter
404 This improves the usefulness of commit_delay.
410 Require superuser privileges to set commit_delay because it
411 can now potentially delay other sessions (Simon Riggs)
412 BACKWARD COMPATIBILITY
419 Remove the external PID file on postmaster exit (Peter Eisentraut)
425 Have "session id" in log_line_prefix (%c) always output four hex
426 digits after the period (Bruce Momjian) COMPATIBILITY
437 <title>Replication and Recovery</title>
443 Allow a streaming replication standbys to follow a timeline switch (Heikki Linnakangas)
447 This allows streaming standbys to feed from newly-promoted slaves.
448 Previously slaves required access to a WAL archive directory to
455 Add SQL functions pg_backup_in_progress() and pg_backup_start_time() (Gilles Darold)
459 These functions report the status of base backups.
465 Improve performance of streaming replication log shipping (Andres Freund)
471 Add the last checkpoint's redo location to pg_controldata's output
476 This information is useful for determining the WAL files needed for
483 Allow tooling like pg_receivexlog to run on computers with different
484 architectures (Heikki Linnakangas)
490 Have pg_basebackup --write-recovery-conf output a minimal
491 recovery.conf (Zoltan Boszormenyi, Magnus Hagander)
495 This simplifies setting up a standby server.
501 Allow pg_receivexlog and pg_basebackup -X to handle streaming
502 timeline switches (Heikki Linnakangas)
508 Add wal_receiver_timeout parameter to control the WAL receiver
509 timeout (Amit Kapila)
513 This allows more rapid detection of connection failure. No longer set
514 wal_receiver_status_interval?
520 Rename replication_timeout to wal_sender_timeout (Amit Kapila)
524 BACKWARD COMPATIBILITY
525 This setting controls the WAL sender timeout.
531 Allow recovery.conf to be relocated using configuration variable
532 recovery_config_directory (Simon Riggs)
545 Store WAL in a continuous stream, rather than skipping the last
546 16MB segment every 4GB (Heikki Linnakangas)
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.
606 Correct predicate locking for DROP INDEX CONCURRENTLY (Kevin Grittner)
616 <title>Object Manipulation</title>
622 Add support to event triggers (Dimitri Fontaine, Tom Lane)
626 This allows C functions to be called when specific commands are run.
632 Allow a multi-row VALUES clause in rules to reference OLD/NEW (Tom Lane)
638 Add IF NOT EXISTS clause to CREATE SCHEMA (FabrÃzio de Royes Mello)
644 Throw an error if expiring tuple is again updated or deleted (Kevin Grittner)
651 Have DROP OWNED only remove user-matching GRANTs on shared objects,
652 e.g. databases, tablespaces (AlvaroAacute;lvaro Herrera)
656 Previously it tried to remove such objects, leading to an error.
662 Have REASSIGN OWNED also change ownership of shared objects (AlvaroAacute;lvaro
670 <title><link linkend="SQL-CREATETABLE"><command>CREATE TABLE</></link></title>
676 No longer output messages about implicit index and sequence creation (Robert Haas)
680 These messages now appear with DEBUG1-level output.
686 Allow CREATE TABLE to succeed for a non-existent schema
691 Previously, CREATE TABLE IF EXIST threw an error if the schema was
701 <title>Constraints</title>
707 Change ON UPDATE SET NULL/SET DEFAULT foreign key actions to affect
708 all referenced columns, not just those referenced in the UPDATE
713 Previously only columns referenced in the UPDATE were set to null or DEFAULT.
714 BACKWARD COMPATIBILITY CHANGE
720 Provide clients with constraint violation details as separate fields
725 This allows clients to retrieve table, column, data type, or constraint
726 name error details. Previously such information had to be extracted from
727 error strings. Client language support is required to access these
734 Internally store default foreign key matches (non-FULL, non-PARTIAL) as "simple" (Tom Lane)
738 These were previously stored as "&unspecified&".
739 This changes the value stored in system column
740 pg_constraint.confmatchtype. BACKWARD COMPATIBILITY CHANGE
749 <title><command>ALTER</></title>
755 Add the ALTER TYPE ... IF NOT EXISTS clause when adding enumerated type labels (Andrew
760 This is useful for conditional label creation in transaction blocks.
766 Add ALTER ROLE ALL SET to add settings to all users (Peter Eisentraut)
770 This allows settings to apply to all users in all databases. ALTER
771 DATABASE SET already allowed addition of settings for all users in a
772 single database. postgresql.conf has a similar effect.
778 Add support for ALTER RULE ... RENAME (Ali Dar)
787 <title><link linkend="rules-views"><command>VIEWs</></link></title>
793 Add a materialized view relations (Kevin Grittner)
797 Unlink ordinary views, where the base tables are read on every access,
798 materialized views create physical tables at creation or refresh time.
799 Access to the materialized view reads from these materialized physical
800 tables. There is no facility for incrementally refreshing materialized
801 views or auto-accessing them via base table access.
807 Make simple views auto-updatable (Dean Rasheed)
811 INSTEAD rules are still available for complex views.
817 Allow views and rules to handle cases where referenced tables are
818 renamed, or columns are renamed, added, or dropped (Tom Lane)
819 HOW DOES IT HANDLE A DROPPED REFERENCED COLUMN?
825 Add CREATE RECURSIVE VIEW syntax (Peter Eisentraut)
829 Internally this is translated into CREATE VIEW ... WITH RECURSIVE.
835 When converting a table to a view, remove its system columns (Tom Lane)
847 <title>Data Types</title>
853 Increase the maximum length of large objects from 2GB to 4TB (Nozomi
858 This change includes new libpq and server-side 64-bit-enabled functions.
864 Allow text timezone designations, e.g. "America/Chicago" when using the
865 ISO "T" timestamptz format (Bruce Momjian)
878 Add operators and functions to extract values from JSON data strings
885 Allow JSON data strings to be converted into records (Andrew Dunstan)
891 Add functions to convert values, records, and hstore data to JSON (Andrew Dunstan)
903 <title>Functions</title>
909 Add array_remove() and array_replace() functions (Marco Nenciarini, Gabriele Bartolini)
915 Allow concat() and format() to properly expand VARIADIC-labeled
916 arguments (Pavel Stehule)
922 Improve format() to handle field width and left/right alignment
929 Have to_char(), to_date(), and to_timestamp() properly handle
930 negative century designations (CC) (Bruce Momjian)
934 Previously the behavior was either wrong or inconsistent with
935 positive/AD handling, e.g. format mask 'IYYY-IW-DY'.
941 Have to_date() and to_timestamp() return proper results when mixing
942 ISO and Gregorian week/day designations (Bruce Momjian)
948 Cause pg_get_viewdef() to default to wrapping after every SELECT
949 target list and FROM entry (Marko Tiikkaja)
953 This causes view output, like from pg_dump, to be more narrow.
959 Have map_sql_value_to_xml_value() properly expand domains (Pavel
966 Force cached functions to be replanned if the search_path changes (Tom Lane)
970 Previously functions already run in the current session ignored changes
980 <title>Server-Side Languages</title>
986 Allow SPI functions to access the number of rows processed by COPY (Pavel
994 <title><link linkend="plpgsql">PL/pgSQL</link> Server-Side Language</title>
1000 Allow PL/pgSQL to use RETURN with a composite-type expressions (Asif
1005 Previously RETURN could only reference composite-type variables.
1011 Allow PL/pgSQL to access the number of rows processed by COPY (Pavel
1016 The command is GET DIAGNOSTICS x = ROW_COUNT.
1022 Allow greater flexibility in where keywords can be used in PL/pgSQL (Tom Lane)
1031 <title><link linkend="plpython">PL/Python</link> Server-Side Language</title>
1037 Add PL/Python result object string handler (Peter Eisentraut)
1041 This allows plpy.debug(rv) to output something reasonable.
1047 Have PL/Python convert oid values to a proper Python numeric type (Peter Eisentraut)
1053 Handle SPIErrors raised explicitly with PL/Python's RAISE the same as
1054 as internal SPI errors (Oskari Saarenmaa and Jan Urbanski)
1065 <title>Client Applications</title>
1071 Add command-line utility pg_isready to check if the server is ready
1072 to accept connections (Phil Sorber)
1078 Support multiple --table arguments for pg_restore, clusterdb,
1079 reindexdb, and vacuumdb (Josh Kupershmidt)
1083 This is similar to the pg_dump --table support.
1089 Add -d option to pg_dumpall, pg_basebackup, pg_receivexlog to
1090 specify the connection string (Amit Kapila)
1096 Allow pg_ctl --idempotent to a 'success' return code if the requested
1097 start/stop action fails, but the cluster is already in the requested
1098 state (Peter Eisentraut)
1104 Change pg_ctl to return an error code if start fails because the
1105 server is already running (Peter Eisentraut)
1111 Add libpq function PQconninfo() to return connection information
1112 (Zoltan Boszormenyi, Magnus Hagander)
1119 <title><link linkend="APP-PSQL"><application>psql</></link></title>
1125 Adjust function cost settings so psql tab completion and pattern
1126 searching is more efficient (Tom Lane)
1132 Improve psql tab completion (Jeff Janes, Peter Eisentraut)
1138 Allow the psql --single-transaction mode to work when reading from
1139 standard input (Fabien Coelho, Robert Haas)
1143 Previously this option only worked when reading from a file.
1149 Remove psql warning when connecting to an older server (Peter Eisentraut)
1153 The warning when connecting to a newer server was retained.
1160 <title>Backslash Commands</title>
1166 Add psql \watch command to repeatedly execute commands (Will
1173 Add psql command \gset to store query results in psql variables
1180 Add SSL information to psql's \conninfo command (Alastair Turner)
1186 Add "Security" label to psql \df+ output (Jon Erdman)
1192 Allow psql \l to accept a database name pattern (Peter Eisentraut)
1198 In psql, do not allow \connect to use defaults if there is no active
1199 connection (Bruce Momjian)
1203 This might be the case if the server had crashed.
1209 Properly reset state if psql's "\g file" command failed (Tom Lane)
1213 Previously failed commands discarded output from subsequent commands.
1222 <title>Output</title>
1228 Add a 'latex-longtable' output format to psql (Bruce Momjian)
1232 Longtable allows tables to span multiple pages.
1238 Add a border=3 output mode to the psql 'latex' format (Bruce Momjian)
1244 In psql tuples-only and expanded modes, no longer output "(No rows)"
1251 In psql, no longer print an empty line for unaligned, expanded
1252 output for zero rows (Peter Eisentraut)
1263 <title><link linkend="APP-PGDUMP"><application>pg_dump</></link></title>
1269 Add pg_dump --jobs to dump in parallel (Joachim Wieland)
1275 Have pg_dump output functions in a predictable order (Joel Jacobson)
1281 Fix tar files emitted by pg_dump and pg_basebackup to be POSIX
1282 conformant (Brian Weaver, Tom Lane)
1288 Add -d/--dbname option to pg_dump, for consistency with other client
1289 commands (Heikki Linnakangas)
1293 The database name could already be supplied last without a flag.
1302 <title><link linkend="APP-INITDB"><application>initdb</></link></title>
1308 Have initdb fsync the newly created data directory (Jeff Davis)
1312 This can be disabled by using --nosync.
1318 Add initdb --sync-only option to sync the data directory to durable
1319 storage (Bruce Momjian)
1323 This is used by pg_upgrade.
1329 Have initdb issue a warning about placing the data directory at the
1330 top of file system mount points (Bruce Momjian)
1341 <title>Source Code</title>
1347 Add an embedded list interface (Andres Freund)
1353 Add infrastructure to better support plug-in background worker
1354 processes (AlvaroAacute;lvaro Herrera)
1360 Create libpgcommon and move pg_malloc() and other functions there
1361 (AlvaroAacute;lvaro Herrera, Andres Freund)
1365 This allows libpgport to be used solely for porting code.
1371 Add compiler designations to indicate some ereport() and elog()
1372 calls do not return (Peter Eisentraut, Andres Freund, Tom Lane,
1379 Remove typedefs for int2/int4 as they are better represented as int16/int32 (Peter Eisentraut)
1385 Create a centralized timeout API (Zoltán Böszörményi)
1391 Rewrite pgindent in Perl (Andrew Dunstan)
1397 Fix install-strip on Mac OS X (Peter Eisentraut)
1403 Remove configure flag --disable-shared, as it is no longer used (Bruce Momjian)
1409 Add emacs macro to match Postgres perltidy formatting (Peter
1416 Run tool to check the keyword list when the backend grammar is changed (Tom Lane)
1422 Standardize on naming of client-side memory allocation functions (Tom Lane)
1428 Centralize flex and bison 'make' rules (Peter Eisentraut)
1432 This is useful for pgxs authors.
1438 Add Assert() functionality to client-side code for frontend code (Andrew Dunstan)
1444 Change many internal many backend functions to return OIDs rather
1445 than void (Dimitri Fontaine)
1449 This is useful for event triggers.
1455 Allow options to be passed to the regression test output comparison
1456 utility via PG_REGRESS_DIFF_OPTS (Peter Eisentraut)
1462 Invent pre-commit/pre-prepare/pre-subcommit events for transaction
1463 callbacks (Tom Lane)
1467 Loadable modules that use transaction callbacks might need modification
1468 to handle these new event types.
1474 Add function pg_identify_object() to dump an object in
1475 machine-readable format (AlvaroAacute;lvaro Herrera)
1481 Improve ability to detect official timezone abbreviation changes
1488 Add pkg-config support libpq and ecpg libraries (Peter Eisentraut)
1494 Add post-ALTER-object server hooks (KaiGai Kohei)
1500 Remove src/tool/backend, now that the content is on the Postgres
1501 wiki (Bruce Momjian)
1507 Split out WAL reading as an independent facility (Andres Freund, Heikki
1514 Allow PL/Python to support platform-specific include directories (Peter Eisentraut)
1520 Allow PL/Python on OS X to build against custom versions of Python
1530 <title>Additional Modules</title>
1536 Have oid2name, pgbench, and vacuumlo set fallback_application_name (Amit Kapila)
1542 Improve output of pg_test_timing (Bruce Momjian)
1548 Improve pg_test_fsync output (Peter Geoghegan)
1554 Improve contrib/dblink option validator (Tom Lane)
1564 Add a Postgres foreign data wrapper contrib module (Shigeru Hanada)
1570 Add pg_xlogdump contrib program (Andres Freund)
1576 Allow write to Postgres foreign tables (KaiGai Kohei)
1580 Other foreign data wrappers can now also potentially support write
1587 Improve pg_trgm handling of multibyte characters (Tom Lane)
1593 Add support for indexing of regular-expression searches in
1594 contrib/pg_trgm (Alexander Korotkov)
1601 <title><link linkend="pgupgrade"><application>pg_upgrade</></link></title>
1607 Increase pg_upgrade logging content by showing executed command
1608 (AlvaroAacute;lvaro Herrera)
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 Improve pg_upgrade's status display during copy/link (Bruce Momjian)
1645 Allow pg_upgrade --jobs to do parallelism (Bruce Momjian)
1649 This allows parallel schema dump/restore of databases, as well as
1650 parallel copy/link of data files per tablespace.
1659 <title><link linkend="pgbench"><application>pgbench</></link></title>
1664 Add --foreign-keys option to pgbench (Jeff Janes)
1668 This adds foreign key constraints to tables, for use in foreign
1669 key performance testing.
1675 Reduce and improve the status message output of pgbench's
1676 initialization mode (Robert Haas, Peter Eisentraut)
1682 Add pg_bench --sampling-rate option to control the percentage of
1683 transactions logged (Tomas Vondra)
1689 Add pgbench -q mode to print one output line every five seconds (Tomas Vondra)
1693 Output pgbench elapsed and estimated remaining time during
1694 initialization logging (Tomas Vondra)
1700 Allow pgbench to aggregate performance statistics and produce output
1701 every --aggregate-interval specified seconds (Tomas Vondra)
1707 Allow pgbench to use a larger scale factor (Greg Smith)
1718 <title>Documentation</title>
1724 Improve WINDOW function documentation (Bruce Momjian, Tom Lane)
1730 Add instructions for setting up the documentation tool chain on
1731 Mac OS X (Peter Eisentraut)
1737 Update FreeBSD kernel configuration documentation (Brad Davis)
1743 Allow EPUB-format documentation to be created (Peter Eisentraut)
1749 Improve commit_delay documentation (Peter Geoghegan)