Development Versions: 14 / devel
This documentation is for an unsupported version of PostgreSQL.
You may want to view the same page for the current version, or one of the other supported versions listed above instead.

E.1. Release 14

Release date: 2021-??-?? (AS OF 2021-05-15)

E.1.1. Overview

PostgreSQL 14 contains many new features and enhancements, including:

    The above items and other new features of PostgreSQL 14 are explained in more detail in the sections below.

    E.1.2. Migration to Version 14

    A dump/restore using pg_dumpall or use of pg_upgrade or logical replication is required for those wishing to migrate data from any previous release. See Section 19.6 for general information on migrating to new major releases.

    Version 14 contains a number of changes that may affect compatibility with previous releases. Observe the following incompatibilities:

    • Prevent the containment operators (<@ and @>) for contrib/intarray from using GiST indexes (Tom Lane)

      Previously a full GiST index scan was required, so just avoid that and scan the heap, which is faster. Indexes created for this purpose should be removed.

    • Remove deprecated containment operators @ and ~ for built-in geometric data types and contrib modules cube, hstore, intarray, and seg (Justin Pryzby)

      The more consistent <@ and @> have been recommended for many years.

    • Fix to_tsquery() and websearch_to_tsquery() to properly parse query text containing discarded tokens (Alexander Korotkov)

      Certain discarded tokens, like underscore, caused the output of these functions to produce incorrect tsquery output, e.g., both websearch_to_tsquery('"pg_class pg"') and to_tsquery('pg_class <-> pg') used to output '( pg & class ) <-> pg', but now both output 'pg <-> class <-> pg'.

    • Fix websearch_to_tsquery() to properly parse multiple adjacent discarded tokens in quotes (Alexander Korotkov)

      Previously, quoted text that contained multiple adjacent discarded tokens were treated as multiple tokens, causing incorrect tsquery output, e.g., websearch_to_tsquery('"aaa: bbb"') used to output 'aaa <2> bbb', but now outputs 'aaa <-> bbb'.

    • Change the default of the password_encryption server parameter to scram-sha-256 (Peter Eisentraut)

      Previously it was md5. All new passwords will be stored as SHA256 unless this server variable is changed or the password is specified in md5 format. Also, the legacy (and undocumented) boolean-like values which were previously synonyms for md5 are no longer accepted.

    • Overhaul the specification of clientcert in pg_hba.conf (Kyotaro Horiguchi)

      Values 1/0/no-verify are no longer supported; only the strings verify-ca and verify-full can be used. Also, disallow verify-ca if cert authentication is enabled since cert requires verify-full checking.

    • Remove support for SSL compression (Daniel Gustafsson, Michael Paquier)

      This was already disabled by default in previous Postgres releases, and most modern OpenSSL and TLS versions no longer support it.

    • Remove server and libpq support for the version 2 wire protocol (Heikki Linnakangas)

      This was last used as the default in Postgres 7.2 (year 2002).

    • Change EXTRACT to return the NUMERIC data type (Peter Eisentraut)

      EXTRACT(date) now throws an error for units that are not part of the date data type.

    • Fix handling of infinite window function ranges (Tom Lane)

      Previously window frame clauses like 'inf' PRECEDING AND 'inf' FOLLOWING returned incorrect results.

    • Prevent tablefunc's function normal_rand() from accepting negative values (Ashutosh Bapat)

      Negative values produced undesirable results.

    • Change var_samp() and stddev_samp() with numeric parameters to return NULL for a single NaN value (Tom Lane)

      Previously NaN was returned.

    • Remove factorial operators ! and !! (Mark Dilger)

      The factorial() function is still supported. Also remove function numeric_fac().

    • Disallow factorial() of negative numbers (Peter Eisentraut)

      Previously such cases returned 1.

    • Remove support for postfix (right-unary) operators (Mark Dilger)

      pg_dump and pg_upgrade will warn if postfix operators are being dumped.

    • Allow \D and \W shorthands to match newlines in newline-sensitive mode (Tom Lane)

      Previously they did not match; [^[:digit:]] or [^[:word:]] can be used to get the old behavior.

    • Improve handling of regular expression back-references (Tom Lane)

      For example, disregard ^ in its expansion in \1 in "(^\d+).*\1".

    • Disallow \w as range start/end in character classes (Tom Lane)

      This previously was allowed but produced incorrect results.

    • Force custom server variable names to match the pattern used for unquoted SQL identifiers (Tom Lane)

    • Return false for has_column_privilege() checks on non-existent or dropped columns when using attribute numbers (Joe Conway)

      Previously such attribute numbers returned an invalid column error.

    • Pass doubled quote marks in ecpg SQL command strings literally (Tom Lane)

      Previously 'abc''def' was passed to the server as 'abc'def', and "abc""def" was passed as "abc"def".

    • Disallow single-quoting of the language name in the CREATE/DROP LANGUAGE command (Peter Eisentraut)

    • Remove contrib program pg_standby (Justin Pryzby)

    • Remove composite types for sequences or toast tables (Tom Lane)

    • Remove operator_precedence_warning setting (Tom Lane)

      This was needed for warning applications about PostgreSQL 9.5 changes.

    E.1.3. Changes

    Below you will find a detailed account of the changes between PostgreSQL 14 and the previous major release.

    E.1.3.1. Server

    • Add predefined roles pg_read_all_data and pg_write_all_data (Stephen Frost)

      These non-login roles give read-only/write-only access to all objects.

    • Add a predefined role to match the database owner (Noah Misch)

      It is called pg_database_owner; this is useful in template databases.

    • Remove temporary files after backend crashes (Euler Taveira)

      These files were previously retained for debugging purposes; deletion can be disabled with remove_temp_files_after_crash.

    • Add long-running queries to be canceled if the client disconnects (Sergey Cherkashin, Thomas Munro)

      The server variable client_connection_check_interval allows supporting operating systems, e.g., Linux, to automatically cancel queries by disconnected clients.

    • Add function pg_wait_for_backend_termination() that waits for session exit (Bharath Rupireddy)

      Also add a similar optional wait parameter to pg_terminate_backend().

    • Allow wide tuples to be always added to almost-empty heap pages (John Naylor, Floris van Nee)

      Previously tuples whose insertion would have exceeded the page's fill factor were instead added to new pages.

    • Add Set Server Name Indication (SNI) for SSL connection packets (Peter Eisentraut)

      This can be disabled by turning client option "sslsni" off.

    E.1.3.1.1. Vacuuming
    • Allow vacuum to skip index vacuuming when the number of removable index entries is insignificant (Masahiko Sawada, Peter Geoghegan)

    • Allow VACUUM to eagerly add newly deleted btree pages to the free space map (Peter Geoghegan)

      Previously VACUUM could only place preexisting deleted pages in the free space map.

    • Allow vacuum to deallocate space reserved by trailing unused heap line pointers (Matthias van de Meent, Peter Geoghegan)

    • Speed up vacuuming of databases with many relations (Tatsuhito Kasahara)

    • Reduce the default value of vacuum_cost_page_miss (Peter Geoghegan)

      This new default better reflects current hardware capabilities.

    • Add ability to skip vacuuming of TOAST tables (Nathan Bossart)

      VACUUM now has a PROCESS_TOAST which can be set to false to disable TOAST processing, and vacuumdb has a --no-process-toast option.

    • Have COPY FREEZE appropriately update page visibility bits (Anastasia Lubennikova, Pavan Deolasee, Jeff Janes)

    • Cause vacuum operations to be aggressive if the table is near xid or multixact wraparound (Masahiko Sawada, Peter Geoghegan)

      This is controlled by vacuum_failsafe_age and vacuum_multixact_failsafe_age.

    • Increase warning time and hard limit before transaction id and multi-transaction wraparound (Noah Misch)

      This should reduce the possibility of failures that occur without having issued warnings about wraparound.

    • Autovacuum now analyzes partitioned tables (Yuzuko Hosoya, Álvaro Herrera)

      Insert, update, and delete tuple counts from partitions are now propagated to their parent tables so autovacuum knows when to process them.

    • Add per-index information to autovacuum logging output (Masahiko Sawada)

    E.1.3.1.2. Partitioning
    • Improve the performance of updates/deletes on partitioned tables when only a few partitions are affected (Amit Langote, Tom Lane)

      This also allows updates/deletes on partitioned tables to use execution-time partition pruning.

    • Allow partitions to be detached in a non-blocking manner (Álvaro Herrera)

      The syntax is ALTER TABLE ... DETACH PARTITION ... CONCURRENTLY, and FINALIZE.

    • Allow the arbitrary collations of partition boundary values (Tom Lane)

      Previously it had to match the collation of the partition key.

    E.1.3.1.3. Indexes
    • Allow btree index additions to remove expired index entries to prevent page splits (Peter Geoghegan)

      This is particularly helpful for reducing index bloat on tables whose indexed columns are frequently updated.

    • Allow BRIN indexes to record multiple min/max values per range (Tomas Vondra)

      This is useful if there are groups of values in each page range.

    • Allow BRIN indexes to use bloom filters (Tomas Vondra)

      This allows bloom indexes to be used effectively with data that is not physically localized in the heap.

    • Allow some GiST indexes to be built by presorting the data (Andrey Borodin)

      Presorting happens automatically and allows for faster index creation and smaller indexes.

    • Allow SP-GiST to use INCLUDE'd columns (Pavel Borisov)

    E.1.3.1.4. Optimizer
    • Allow hash lookup of IN clause with many constants (James Coleman, David Rowley)

      Previously the only option was to sequentially scan the list of constants.

    • Increase the number of places extended statistics can be used for OR clause estimation (Tomas Vondra, Dean Rasheed)

    • Allow extended statistics on expressions (Tomas Vondra)

      This allows statistics on a group of expressions and columns, rather than only columns like previously. System view pg_stats_ext_exprs reports such statistics. ALTER TABLE ... ALTER COLUMN ... TYPE RESETS STASTISTICS?

    • Allow efficient heap scanning of a range of tids (Edmund Horner, David Rowley)

      Previously a sequential scan was required for non-equality tid specifications.

    • Fix EXPLAIN CREATE TABLE AS and EXPLAIN CREATE MATERIALIZED VIEW to honor IF NOT EXISTS (Bharath Rupireddy)

      Previously, if the object already exists, EXPLAIN would fail.

    E.1.3.1.5. General Performance
    • Improve the speed of computing MVCC visibility snapshots on systems with many CPUs and high session counts (Andres Freund)

      This also improves performance when there are many idle sessions.

    • Add executor method to cache results from the inner-side of nested loop joins (David Rowley)

      This is useful if only a small percentage of rows is checked on the inner side.

    • Allow window functions to perform incremental sorts (David Rowley)

    • Improve the I/O performance of parallel sequential scans (Thomas Munro, David Rowley)

      This was done by allocating blocks in groups to parallel workers.

    • Allow a query referencing multiple foreign tables to perform foreign table scans in parallel (Robert Haas, Kyotaro Horiguchi, Thomas Munro, Etsuro Fujita)

      The postgres_fdw supports these type of scans if "async_capable" is set.

    • Allow analyze to do page prefetching (Stephen Frost)

      This is controlled by maintenance_io_concurrency.

    • Improve the performance of regular expression comparisons (Tom Lane)

    • Dramatically improve Unicode normalization (John Naylor)

      This speeds normalize() and IS NORMALIZED.

    • Add ability to use LZ4 compression on TOAST data (Dilip Kumar)

      This can be set at the column level, or set as a default via server setting default_toast_compression. The server must be compiled with --with-lz4 to support this feature; the default is still pglz.

    E.1.3.1.6. Monitoring
    • If server variable compute_query_id is enabled, display the query id in pg_stat_activity, EXPLAIN VERBOSE, csvlog, and optionally in log_line_prefix (Julien Rouhaud)

      A query id computed by an extension will also be displayed.

    • Add system view pg_backend_memory_contexts to report session memory usage (Atsushi Torikoshi, Fujii Masao)

    • Add function pg_log_backend_memory_contexts() to output the memory contexts of arbitrary backends (Atsushi Torikoshi)

    • Improve logging of auto-vacuum and auto-analyze (Stephen Frost, Jakub Wartak)

      This reports I/O timings for auto-vacuum and auto-analyze if track_io_timing is enabled. Also, report buffer read and dirty rates for auto-analyze.

    • Add information about the original user name supplied by the client to the output of log_connections (Jacob Champion)

    E.1.3.1.7. System Views
    • Add view pg_stat_progress_copy to report COPY progress (Josef Šimánek, Matthias van de Meent)

    • Add session statistics to the pg_stat_database system view (Laurenz Albe)

    • Add columns to pg_prepared_statements to report generic and custom plan counts (Atsushi Torikoshi, Kyotaro Horiguchi)

    • Add lock wait start time to pg_locks (Atsushi Torikoshi)

    • Add system view pg_stat_wal which reports WAL activity (Masahiro Ikeda)

    • Add system view pg_stat_replication_slots to report replication slot activity (Sawada Masahiko, Amit Kapila, Vignesh C)

      Function pg_stat_reset_replication_slot() resets slot statistics.

    • Improve pg_stat_activity reporting of walsender processes (Tom Lane)

      Previously only SQL commands were reported.

    • Make the archiver process visible in pg_stat_activity (Kyotaro Horiguchi)

    • Add wait event WalReceiverExit to report WAL receiver exit wait time (Fujii Masao)

    • Implement information schema view routine_column_usage to track columns referenced by function and procedure default expressions (Peter Eisentraut)

    E.1.3.1.8. Authentication
    • Allow the certificate's distinguished name (DN) to be matched for client certificate authentication (Andrew Dunstan)

      The new pg_hba.conf keyword "clientname=DN" allows comparison with certificate attributes beyond the CN and can be combined with ident maps.

    • Allow pg_hba.conf and pg_ident.conf records to span multiple lines (Fabien Coelho)

      A backslash at the end of a line allows record contents to be continued on the next line.

    • Allow the specification of a certificate revocation list (CRL) directory (Kyotaro Horiguchi)

      This is controlled by server variable ssl_crl_dir and libpq connection option sslcrldir. Previously only CRL files could be specified.

    • Allow passwords of an arbitrary length (Tom Lane, Nathan Bossart)

    E.1.3.1.9. Server Configuration
    • Add server setting idle_session_timeout to close idle sessions (Li Japin)

      This is similar to idle_in_transaction_session_timeout.

    • Change checkpoint_completion_target default to 0.9 (Stephen Frost)

      The previous default was 0.5.

    • Add %P to log_line_prefix to report the parallel group leader (Justin Pryzby)

    • Allow unix_socket_directories to specify paths as individual, comma-separated quoted strings (Ian Lawrence Barwick)

      Previously all the paths had to be in a single quoted string.

    • Allow startup allocation of dynamic shared memory (Thomas Munro)

      This is controlled by min_dynamic_shared_memory. This allows more use of huge pages.

    • Add setting huge_page_size to control the size of huge pages used on Linux (Odin Ugedal)

    E.1.3.2. Streaming Replication and Recovery

    • Allow standby servers to be rewound via pg_rewind (Heikki Linnakangas)

    • Allow restore_command setting to be changed during a server reload (Sergei Kornilov)

      You can also set restore_command to an empty string and reload to force recovery to only read from the pg_wal directory.

    • Add server variable log_recovery_conflict_waits to report long recovery conflict wait times (Bertrand Drouvot, Masahiko Sawada)

    • Pause recovery if the primary changes its parameters in a way that prevents replay on the hot standby (Peter Eisentraut)

      Previously the standby would shut down immediately.

    • Add function pg_get_wal_replay_pause_state() to report the recovery state (Dilip Kumar)

      It gives more detailed information than pg_is_wal_replay_paused(), which still exists.

    • Add new server-side variable in_hot_standby (Haribabu Kommi, Greg Nancarrow, Tom Lane)

    • Speed truncation of small tables during recovery on clusters with a large number of shared buffers (Kirk Jamison)

    • Allow file system sync at the start of crash recovery on Linux (Thomas Munro)

      By default, Postgres opens and fsyncs every data file at the start of crash recovery. This new setting, recovery_init_sync_method=syncfs, instead syncs each filesystem used by the database cluster. This allows for faster recovery on systems with many database files.

    • Add function pg_xact_commit_timestamp_origin() to return the commit timestamp and replication origin of the specified transaction (Movead Li)

    • Add the replication origin to the record returned by pg_last_committed_xact() (Movead Li)

    • Allow replication origin functions to be controlled using standard function permission controls (Martín Marqués)

      Previously these functions could only be executed by super-users, and this is still the default.

    • Improve signal handling reliability (Fujii Masao)

      GENERAL ENOUGH?

    E.1.3.2.1. Logical Replication
    • Allow logical replication to stream long in-progress transactions to subscribers (Tomas Vondra, Dilip Kumar, Amit Kapila, Ajin Cherian, Nikhil Sontakke, Stas Kelvich)

      Previously transactions that exceeded logical_decoding_work_mem were written to disk until the transaction completed.

    • Enhance the logical replication API to allow streaming large in-progress transactions (Tomas Vondra, Dilip Kumar, Amit Kapila)

      The output functions begin with "stream". test_decoding also supports these.

    • Allow multiple transactions during table sync in logical replication (Peter Smith, Amit Kapila, and Takamichi Osumi)

    • Immediately WAL-log subtransaction and top-level XID association (Tomas Vondra, Dilip Kumar, Amit Kapila)

      This is useful for logical decoding.

    • Enhance logical decoding APIs to handle two-phase commits (Ajin Cherian, Amit Kapila, Nikhil Sontakke, Stas Kelvich)

      This is controlled via pg_create_logical_replication_slot().

    • Generate WAL invalidations message during command completion when using logical replication (Dilip Kumar, Tomas Vondra, Amit Kapila)

      When logical replication is disabled, WAL invalidation messages are generated at transaction completion. This allows logical streaming of in-progress transactions.

    • Allow logical decoding to more efficiently process cache invalidation messages (Dilip Kumar)

      This allows Logical decoding to work efficiently in presence of a large amount of DDL.

    • Allow control over whether logical decoding messages are sent to the replication stream (David Pirotte, Euler Taveira)

    • Allow logical replication subscriptions to use binary transfer mode (Dave Cramer)

      This is faster than text mode, but slightly less robust.

    • Allow logical decoding to be filtered by xid (Markus Wanner)

    E.1.3.3. SELECT, INSERT

    • Reduce the number of keywords that can't be used as column labels without "AS" (Mark Dilger)

      There are now 90% fewer restricted keywords.

    • Allow an alias to be specified for JOIN's USING clause (Peter Eisentraut)

      The alias is created by using AS after the USING clause and represents an alias for the USING columns.

    • Allow DISTINCT to be added to GROUP BY to remove duplicate GROUPING SET combinations (Vik Fearing)

      For example, GROUP BY CUBE (a,b), CUBE (b,c) will generate duplicate grouping combinations without DISTINCT.

    • Properly handle DEFAULT values for columns in multi-column inserts (Dean Rasheed)

      This used to throw an error.

    • Add SQL-standard SEARCH and CYCLE clauses for common table expressions (Peter Eisentraut)

      This could be accomplished previously using existing syntax.

    • Allow the WHERE clause of ON CONFLICT to be table-qualified (Tom Lane)

      Only the target table can be referenced.

    E.1.3.4. Utility Commands

    • Allow REFRESH MATERIALIZED VIEW to use parallelism (Bharath Rupireddy)

    • Allow REINDEX to change the tablespace of the new index (Alexey Kondratov, Michael Paquier, Justin Pryzby)

      This is done by specifying a TABLESPACE clause.

    • Allow REINDEX to process all child tables or indexes of a partitioned relation (Justin Pryzby, Michael Paquier)

    • Improve the performance of COPY FROM in binary mode (Bharath Rupireddy, Amit Langote)

    • Preserve SQL standard syntax in view definitions, if possible (Tom Lane)

      Previously non-function call SQL standard syntax, e.g. EXTRACT, were converted to non-SQL standard function calls.

    • Add the SQL-standard clause GRANTED BY to GRANT and REVOKE (Peter Eisentraut)

    • Add OR REPLACE for CREATE TRIGGER (Takamichi Osumi)

      This allows pre-existing triggers to be conditionally replaced.

    • Allow control over whether foreign servers keep connections open after transaction completion (Bharath Rupireddy)

      This is controlled by keep_connections and defaults to on.

    • Allow TRUNCATE to operate on foreign tables (Kazutaka Onishi, Kohei KaiGai)

      The postgres_fdw module also now supports this.

    • Allow publications to be more easily added and removed (Japin Li)

      The new syntax is ALTER SUBSCRIPTION ... ADD/DROP PUBLICATION. This avoids having to specify all publications to add/remove entries.

    • Add primary keys, unique constraints, and foreign keys to system catalogs (Peter Eisentraut)

      This helps GUI tools analyze the system tables.

    • Allow CURRENT_ROLE every place CURRENT_USER is accepted (Peter Eisentraut)

    E.1.3.5. Data Types

    • Allow extensions and built-in data types to implement subscripting (Dmitry Dolgov)

      Previously subscript handling was hard-coded into the server, so that subscripting could only be applied to array types. This change allows subscript notation to be used to extract or assign portions of a value of any type for which the concept makes sense.

    • Allow subscripting of JSONB (Dmitry Dolgov)

      JSONB subscripting can be used to extract and assign to portions of JSONB documents.

    • Add support for multirange data types (Paul Jungwirth, Alexander Korotkov)

      These are like range data types, but they allow the specification of multiple, ordered, non-overlapping ranges. All existing range types now also support multirange versions.

    • Add point operators <<| and |>> to be strictly above/below geometry (Emre Hasegeli)

      Previously >^ and <^ were marked as performing this test, but non-point geometric operators used these operators for non-strict comparisons, leading to confusion. The old operators still exist but will be eventually removed. ACCURATE?

    • Add support for the stemming of languages Armenian, Basque, Catalan, Hindi, Serbian, and Yiddish (Peter Eisentraut)

    • Allow tsearch data files to have unlimited line lengths (Tom Lane)

      The previous limit was 4k bytes. Also remove function t_readline().

    • Add support for infinity and -infinity values to the numeric data type (Tom Lane)

      Floating point data types already supported these.

    • Improve the accuracy of floating point computations involving infinity (Tom Lane)

    • Have non-zero float values divided by infinity return zero (Kyotaro Horiguchi)

      Previously such operations produced underflow errors.

    • Cause floating-point division of NaN by zero to return NaN (Tom Lane)

      Previously this returned an error. Division with Numerics always returned NaN.

    • Add operators to add and subtract LSN and numeric (byte) values (Fujii Masao)

    • Allow binary data transfer to be more forgiving of array and record OID mismatches (Tom Lane)

    • Create composite array types for most system relations (Wenjing Zeng)

    E.1.3.6. Functions

    • Allow SQL-language functions and procedures to use SQL-standard function bodies (Peter Eisentraut)

      Previously only single-quoted or $$-quoted function bodies were supported.

    • Allow procedures to have OUT parameters (Peter Eisentraut)

    • Allow some array functions to operate on a mix of compatible data types (Tom Lane)

      The functions are array_append() array_prepend(), array_cat(), array_position(), array_positions(), array_remove(), array_replace(), and width_bucket(). Previously only identical data types could be used.

    • Add SQL-standard trim_array() function (Vik Fearing)

      This can already be done with array slices.

    • Add bytea equivalents of ltrim() and rtrim() (Joel Jacobson)

    • Support negative indexes in split_part() (Nikhil Benesch)

      Negative values start from the last field and count backward.

    • A string_to_table() function to split a string on delimiters (Pavel Stehule)

      This is similar to the regexp_split_to_table() function.

    • Add unistr() function to allow Unicode characters to be specified as backslash-hex escapes in strings (Pavel Stehule)

      This is similar to how Unicode can be specified in literal string.

    • Add bit_xor XOR aggregate function (Alexey Bashtanov)

    • Add function bit_count() to return the number of bits set in a bit or byte string (David Fetter)

    • Add date_bin function (John Naylor)

      The function date_bin "bins" the input timestamp into a specified interval aligned with a specified origin.

    • Allow make_timestamp/make_timestamptz to accept negative years (Peter Eisentraut)

      They are interpreted as BC years.

    • Add newer regular expression substring() syntax (Peter Eisentraut)

      The new syntax is SUBSTRING(text SIMILAR pattern ESCAPE escapechar). The previous standard syntax was SUBSTRING(text FROM pattern FOR escapechar), and is still supported by Postgres.

    • Allow complemented character class escapes \D, \S, and \W within regex brackets (Tom Lane)

    • Add [[:word:]] as a character class to match \w (Tom Lane)

    • Allow more flexible data types for default values of lead() and lag() window functions (Vik Fearing)

    • Cause exp() and power() for negative-infinity exponents to return zero (Tom Lane)

      Previously they often returned underflow errors.

    • Mark built-in type coercion functions as leakproof where possible (Tom Lane)

      This allows more use of functions that require type conversion in security-sensitive situations.

    • Mark pg_stat_get_subscription() as returning a set (Tom Lane)

      While it worked in previous releases, it didn't report proper optimizer statistics and couldn't be used in the target list.

    • Prevent inet_server_addr() and inet_server_port() from being run by parallel workers (Masahiko Sawada)

    • Change pg_describe_object(), pg_identify_object(), and pg_identify_object_as_address() to always report helpful error messages for non-existent objects (Michael Paquier)

    E.1.3.7. PL/pgSQL

    • Improve PL/pgSQL's expression and assignment parsing (Tom Lane)

      This adds nested record and array slicing support.

    • Allow plpgsql's RETURN QUERY to execute its query using parallelism (Tom Lane)

    • Improve performance of repeated CALLs within plpgsql procedures (Pavel Stehule, Tom Lane)

    E.1.3.8. Client Interfaces

    • Add pipeline mode to libpq (Craig Ringer, Matthieu Garrigues, Álvaro Herrera)

      This allows multiple queries to be sent and only wait for completion when a specific synchronization message is sent.

    • Enhance libpq's target_session_attrs parameter options (Haribabu Kommi, Greg Nancarrow, Vignesh C, Tom Lane)

      New options are "read-only", "primary", "standby", and "prefer-standby".

    • Improve the output format of libpq's PQtrace() (Aya Iwata, Álvaro Herrera)

    • Allow libpq service files to have unlimited line lengths (Daniel Gustafsson)

      The previous limit was 255 bytes.

    • Allow an ECPG SQL identifier to be linked to a specific connection (Hayato Kuroda)

      This is done via DECLARE ... STATEMENT.

    E.1.3.9. Client Applications

    • Allow reindexdb to change the tablespace of the new index (Michael Paquier)

      This is done by specifying --tablespace.

    • Allow vacuumdb to skip index cleanup and truncation (Nathan Bossart)

      The options are --no-index-cleanup and --no-truncate.

    • Allow pg_dump to dump only certain extensions (Guillaume Lelarge)

      This is controlled by option --extension.

    • Add pgbench permute() function to randomly shuffle values (Fabien Coelho, Hironobu Suzuki, Dean Rasheed)

    • Allow multiple verbose option specifications (-v) to increase the logging verbosity (Tom Lane)

      This is now supported by pg_dump, pg_dumpall, and pg_restore.

    E.1.3.9.1. psql
    • Allow psql's \df and \do commands to specify function and operator argument types (Greg Sabino Mullane, Tom Lane)

      This helps reduce the number of matches for overloaded entries.

    • Add an access method column to psql's \d[i|m|t]+ output (Georgios Kokolatos)

    • Allow psql's \dt and \di to show TOAST tables and their indexes (Justin Pryzby)

    • Add psql command \dX to list extended statistics objects (Tatsuro Yamada)

    • Fix psql's \dT to understand array syntax and backend grammar aliases, like "int" for "integer" (Greg Sabino Mullane, Tom Lane)

    • When editing the previous query or a file with psql's \e, or using \ef and \ev, ignore the contents if the editor exits without saving (Laurenz Albe)

      Previously, such edits would still execute the editor contents.

    • Improve psql's handling of \connect with -reuse-previous (Tom Lane)

      Specifically, properly reuse the password previously specified, and prompt for a new password if the previous one failed.

    • Improve tab completion (Vignesh C, Michael Paquier, Justin Pryzby, Georgios Kokolatos, Julien Rouhaud, ADD NAMES)

    E.1.3.10. Server Applications

    • Add command-line utility pg_amcheck to simplify running contrib/amcheck operations on many relations (Mark Dilger)

    • Add --no-instructions option to initdb (Magnus Hagander)

      This removes the server start instructions that are normally output.

    • Stop pg_upgrade from creating analyze_new_cluster script (Michael Paquier)

      Instead, give comparable vacuumdb instructions.

    • Remove support for the postmaster -o option (Magnus Hagander)

      This option was unnecessary since all passed options could already be specified directly.

    E.1.3.11. Documentation

    • Rename Default Roles to Predefined Roles (Bruce Momjian, Stephen Frost)

    • Add documentation for the factorial() function (Peter Eisentraut)

      With the removal of the ! operator in this release, factorial() is the only built-in way to compute a factorial.

    E.1.3.12. Source Code

    • Add configure option --with-ssl={openssl} to behave like --with-openssl (Daniel Gustafsson, Michael Paquier)

      The option --with-openssl is kept for compatibility.

    • Add support for abstract Unix-domain sockets (Peter Eisentraut)

      This is currently supported on Linux and Windows.

    • Add debug_invalidate_system_caches_always to control cache overwriting (Craig Ringer)

      Previously this could only be controlled at compile time and is enabled only in assert builds.

    • Various improvements in valgrind detection (Álvaro Herrera, Peter Geoghegan)

    • Add a test module for the regular expression package (Tom Lane)

    • Add support for LLVM 12 (Andres Freund)

    • Change SHA1, SHA2, and MD5 hash computations to use the OpenSSL EVP API (Michael Paquier)

      This is more modern and supports FIPS mode.

    • Remove build control over the random library used (Daniel Gustafsson)

    • Add direct conversion routines between EUC_TW and Big5 (Heikki Linnakangas)

    • Add collation versions for FreeBSD (Thomas Munro)

    • Add "amadjustmembers" to the index access method API (Tom Lane)

      REMOVE?

    E.1.3.13. Additional Modules

    • Move query hash computation from pg_stat_statements to the core server (Julien Rouhaud)

      The new server variable compute_query_id's default of 'auto' will automatically enable query id computation when this extension is loaded.

    • Allow pg_stat_statements to track top and nested statements independently (Julien Rohaud)

      Previously, when tracking all statements, identical top and nested statements were tracked together.

    • Add row counts for utility commands to pg_stat_statements (Fujii Masao, Katsuragi Yuta, Seino Yuki)

    • Add pg_stat_statements_info system view to show pg_stat_statements activity (Katsuragi Yuta, Yuki Seino, Naoki Nakamichi)

    • Allow subscripting of hstore values (Tom Lane, Dmitry Dolgov)

    • Allow GiST/GIN pg_trgm indexes to do equality lookups (Julien Rouhaud)

      This is similar to LIKE except no wildcards are honored.

    • Allow the cube data type to be transferred in binary mode (KaiGai Kohei)

    • Add contrib module pg_surgery which allows changes to row visibility (Ashutosh Sharma)

      This is useful for correcting database corruption.

    • Add contrib module old_snapshot to report the XID/time mapping used by an active old_snapshot_threshold (Robert Haas)

    • Allow amcheck to also check heap pages (Mark Dilger)

      Previously it only checked B-Tree index pages.

    • Allow pageinspect to inspect GiST indexes (Andrey Borodin, Heikki Linnakangas)

    • Change pageinspect block numbers to be bigints (Peter Eisentraut)

    • Allow pgstattuple_approx() to report on TOAST tables (Peter Eisentraut)

    • Mark btree_gist functions as parallel safe (Steven Winfield)

    E.1.3.13.1. postgres_fdw
    • Allow postgres_fdw to INSERT rows in bulk (Takayuki Tsunakawa, Tomas Vondra, Amit Langote)

    • Allow postgres_fdw to import table partitions if specified by IMPORT FOREIGN SCHEMA ... LIMIT TO (Matthias van de Meent)

      By default, only the root of partitioned tables is imported.

    • Add postgres_fdw function postgres_fdw_get_connections to report open foreign server connections (Bharath Rupireddy)

    • Add postgres_fdw functions to discard cached connections (Bharath Rupireddy)

    • Allow postgres_fdw to reestablish foreign server connections if necessary (Bharath Rupireddy)

      Previously foreign server restarts could cause foreign table access errors.

    E.1.4. Acknowledgments

    The following individuals (in alphabetical order) have contributed to this release as patch authors, committers, reviewers, testers, or reporters of issues.