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On September 30, 2021 the latest version of PostgreSQL 14 was released! Postgres fans had the opportunity to celebrate the whole week, because 6 days earlier was the first anniversary of version 13. It is therefore a great time to look at the changes that the creators of the top database engine have prepared in the current version. In a word of introduction, let’s first explain what Postgres is and what it means in the current market.

PostgreSQL is an object-relational database management system, developed at the University of California at Berkeley Computer Science Department. With over two decades of development behind it, PostgreSQL is now the most advanced open-source database available anywhere.

History of Postgres

The POSTGRES project, led by Professor Michael Stonebraker, was sponsored among others by the Defense Advanced Research Projects Agency (DARPA). The implementation of POSTGRES began in 1986 and first demo version was operational in 1987.

In 1994, Andrew Yu and Jolly Chen added an SQL language interpreter to POSTGRES. Under a new name, Postgres95 was released to the web as an open-source descendant of the original POSTGRES Berkeley code. Interestingly Postgres95 code was completely ANSI C, trimmed in size by 25% and ran about 30–50% faster compared to POSTGRES.

By 1996, it became clear that the name “Postgres95” would not stand the test of time. So they chose a new name, PostgreSQL, to reflect the relationship between the original POSTGRES and the more recent versions with SQL capability. Worth noting is that they set the version numbering to start at 6.0, putting the numbers back into the sequence originally begun by the Berkeley POSTGRES project.

Postgres, or PostgreSQL?

Many people continue to refer to PostgreSQL as “Postgres” (now rarely in all capital letters) because of tradition or because it is easier to pronounce. This usage is widely accepted as a nickname or alias.

Popularity of Postgres

According to Google Trends, the popularity of PostgreSQL (blue) continues to increase, and its advantage between paid solutions such as Oracle (red) has started to increase dramatically. This happened throughout 2015, when new solutions such as MongoDB (yellow) became more popular.

The graph shows interest over time – the peak of popularity of a topic in Google searches was marked as 100. A value of 50 means that the topic was half as popular.

 

The map shows the popularity of PostgreSQL (blue), Oracle (red), MongoDB (yellow) over the last 10 years. The darker the color, the greater its advantage in a given region. Gray color means no data.

PostgreSQL 14 compared to PostgreSQL 13

Version 14 of the PostgreSQL relational database was released on September 30, 2021 and has a number of new features compared to its predecessor. The creators of the latest version of Postgres noticeably focused on database performance, a new replication method, or emergency mode for garbage-collector. These are only examples of new features that can be found in the latest version of PostgreSQL 14. A comprehensive list of all changes is available below.

Detailed list of new functionalities and changes in PostgreSQL 14

The list has been divided into the following categories: Server, Streaming Replication and Recovery, SELECT, INSERT, Utility Commands, Data types, Functions, PL/PgSQL, Client Interfaces, Client Applications, Server Applications, Documentation, Source Code, Additional Modules. The list below describes any changes between PostgreSQL 14 and the previous major Postgres release.

Server

Change	Additional informations	Author(s)
Add predefined roles pg_read_all_data and pg_write_all_data	These non-login roles can be used to give read or write permission to all tables, views, and sequences	Stephen Frost
Add predefined role pg_database_owner that contains only the current database’s owner	This is especially useful in template databases	Noah Misch
Remove temporary files after backend crashes	Previously, such files were retained for debugging purposes. If necessary, deletion can be disabled with the new server parameter remove_temp_files_after_crash	Euler Taveira
Allow long-running queries to be canceled if the client disconnects	The server parameter client_connection_check_interval allows control over whether loss of connection is checked for intra-query (this is supported on Linux and a few other operating systems)	Sergey Cherkashin, Thomas Munro
Add an optional timeout parameter to pg_terminate_backen	–	–
Allow wide tuples to be always added to almost-empty heap pages	Previously tuples whose insertion would have exceeded the page’s fill factor were instead added to new pages	John Naylor, Floris van Ne
Add Server Name Indication (SNI) in SSL connection packets	This can be disabled by turning off client connection option sslsni	Peter Eisentraut

Server – vacuuming

Vacuum is another name for Garbage-Collector, in other words a tool for collecting and removing unnecessary things (so-called garbage) from the database – e.g. dead tuples.

Change	Additional informations	Author(s)
Allow vacuum to skip index vacuuming when the number of removable index entries is insignificant	The vacuum parameter INDEX_CLEANUP has a new default of auto that enables this optimization	Masahiko Sawada, Peter Geoghegan
Allow vacuum to more eagerly add deleted btree pages to the free space map	Previously vacuum could only add pages to the free space map that were marked as deleted by previous vacuums	Peter Geoghegan
Allow vacuum to reclaim space used by unused trailing heap line pointers	–	Mathias van de Ment, Peter Geoghegan
Allow vacuum to be more aggressive in removing dead rows during minimal-locking index operations	Specifically, CREATE INDEX CONCURRENTLY and REINDEX CONCURRENTLY no longer limit the dead row removal of other relations	Álvaro Herera
Speed up vacuuming of databases with many relations	–	Tatsuhito Kasahara
Reduce the default value of vacuum_cost_page_miss to better reflect current hardware capabilities	–	Peter Geoghega
Add ability to skip vacuuming of TOAST tables	VACUUM now has a PROCESS_TOAST option which can be set to false to disable TOAST processing, and vacuumdb has a –no-process-toast option	Nathan Bosart
Have COPY FREEZE appropriately update page visibility bits	–	Anastasia Lubenikova, Pavan Deolase, Jef Janes
Cause vacuum operations to be more aggressive if the table is near xid or multixact wraparound	This is controlled by vacuum_failsafe_age and vacuum_multixact_failsafe_age	Masahiko Sawada, Peter Geoghegan
Increase warning time and hard limit before transaction id and multi-transaction wraparound	This should reduce the possibility of failures that occur without having issued warnings about wraparound	Noah Misch
Add per-index information to autovacuum logging output	–	Masahiko Sawada

Server – partitioning

Change	Additional informations	Author(s)
Improve the performance of updates and deletes on partitioned tables with many partitions	This change greatly reduces the planner’s overhead for such cases, and also allows updates/deletes on partitioned tables to use execution-time partition pruning	Amit Langote, Tom Lane
Allow partitions to be detached in a non-blocking manner	The syntax is ALTER TABLE … DETACH PARTITION … CONCURRENTLY, and FINALIZE	Álvaro Herrera
Ignore COLLATE clauses in partition boundary values	Previously any such clause had to match the collation of the partition key; but it’s more consistent to consider that it’s automatically coerced to the collation of the partition key	Tom Lane

Server – indexes

Change	Additional informations	Author(s)
Allow btree index additions to remove expired index entries to prevent page splits	This is particularly helpful for reducing index bloat on tables whose indexed columns are frequently updated	Peter Geoghegan
Allow BRIN indexes to record multiple min/max values per range	This is useful if there are groups of values in each page range	Tomas Vondra
Allow BRIN indexes to use bloom filters	This allows BRIN indexes to be used effectively with data that is not well-localized in the heap	Tomas Vondra
Allow some GiST indexes to be built by presorting the data	Presorting happens automatically and allows for faster index creation and smaller indexes	Andrey Borodin
Allow SP-GiST indexes to contain INCLUDE’d columns	–	Pavel Borisov

Server – optimizer

Change	Additional informations	Author(s)
Allow hash lookup for IN clauses with many constants	Previously the code always sequentially scanned the list of values	James Coleman, David Rowley
Increase the number of places extended statistics can be used for OR clause estimation	–	Tomas Vondra, Dean Rasheed
Allow extended statistics on expressions	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	Tomas Vondra
Allow efficient heap scanning of a range of TIDs	Previously a sequential scan was required for non-equality TID specifications	Edmund Horner, David Rowley
Fix EXPLAIN CREATE TABLE AS and EXPLAIN CREATE MATERIALIZED VIEW to honor IF NOT EXISTS	Previously, if the object already existed, EXPLAIN would fail	Bharath Rupireddy

Server – general performance

Change	Additional informations	Author(s)
Improve the speed of computing MVCC visibility snapshots on systems with many CPUs and high session counts	This also improves performance when there are many idle sessions	Andres Freund
Add executor method to memoize results from the inner side of a nested-loop join	This is useful if only a small percentage of rows is checked on the inner side. It can be disabled via server parameter enable_memoize	David Rowley
Allow window functions to perform incremental sorts	–	David Rowley
Improve the I/O performance of parallel sequential scans	This was done by allocating blocks in groups to parallel workers	Thomas Munro, David Rowley
Allow a query referencing multiple foreign tables to perform foreign table scans in parallel	postgres_fdw supports this type of scan if async_capable is set	Robert Haas, Kyotaro Horiguchi, Thomas Munro, Etsuro Fujita
Allow analyze to do page prefetching	This is controlled by maintenance_io_concurrency	Stephen Frost
Improve performance of regular expression searches	–	Tom Lane
Dramatically improve Unicode normalization	This speeds normalize() and IS NORMALIZED	John Naylor
Add ability to use LZ4 compression on TOAST data	This can be set at the column level, or set as a default via server parameter default_toast_compression. The server must be compiled with –with-lz4 to support this feature. The default setting is still pglz	Dilip Kumar

Server – monitoring

Change	Additional informations	Author(s)
If server parameter compute_query_id is enabled, display the query id in pg_stat_activity, EXPLAIN VERBOSE, csvlog, and optionally in log_line_prefix	A query id computed by an extension will also be displayed	Julien Rouhaud
Improve logging of auto-vacuum and auto-analyze	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	Stephen Frost, Jakub Wartak
Add information about the original user name supplied by the client to the output of log_connections	–	Jacob Champion

Server – system views

Change	Additional informations	Author(s)
Add system view pg_stat_progress_copy to report COPY progress	–	Josef Šimánek, Matthias van de Meent
Add system view pg_stat_wal to report WAL activity	–	Masahiro Ikeda
Add system view pg_stat_replication_slots to report replication slot activity	The function pg_stat_reset_replication_slot() resets slot statistics	Sawada Masahiko, Amit Kapila, Vignesh C
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
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
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

Server – authentication

Change	Additional informations	Author(s)
Allow an SSL certificate’s distinguished name (DN) to be matched for client certificate authentication	The new pg_hba.conf option clientname=DN allows comparison with certificate attributes beyond the CN and can be combined with ident maps	Andrew Dunstan
Allow pg_hba.conf and pg_ident.conf records to span multiple lines	A backslash at the end of a line allows record contents to be continued on the next line.	Fabien Coelho
Allow the specification of a certificate revocation list (CRL) directory	This is controlled by server parameter ssl_crl_dir and libpq connection option sslcrldir. Previously only single CRL files could be specified	Kyotaro Horiguchi
Allow passwords of an arbitrary length	–	Tom Lane, Nathan Bossart

Server – server configuration

Change	Additional informations	Author(s)
Add server parameter idle_session_timeout to close idle sessions	This is similar to idle_in_transaction_session_timeout	Li Japin
Change checkpoint_completion_target default to 0.9	The previous default was 0.5	Stephen Frost
Allow %P in log_line_prefix to report the parallel group leader’s PID for a parallel worker	–	Justin Pryzby
Allow unix_socket_directories to specify paths as individual, comma-separated quoted strings	Previously all the paths had to be in a single quoted string.	Ian Lawrence Barwick
Allow startup allocation of dynamic shared memory	This is controlled by min_dynamic_shared_memory. This allows more use of huge pages	Thomas Munro
Add server parameter huge_page_size to control the size of huge pages used on Linux	–	Odin Ugedal

Streaming replication and recovery

Change	Additional informations	Author(s)
Allow standby servers to be rewound via pg_rewind	–	Heikki Linnakangas
Allow the restore_command setting to be changed during a server reload	You can also set restore_command to an empty string and reload to force recovery to only read from the pg_wal directory	Sergei Kornilov
Add server parameter log_recovery_conflict_waits to report long recovery conflict wait times	–	Bertrand Drouvot, Masahiko Sawada
Pause recovery on a hot standby server if the primary changes its parameters in a way that prevents replay on the standby	Previously the standby would shut down immediately	Peter Eisentraut
Add function pg_get_wal_replay_pause_state() to report the recovery state	It gives more detailed information than pg_is_wal_replay_paused(), which still exists	Dilip Kumar
Add new read-only server parameter in_hot_standby	This allows clients to easily detect whether they are connected to a hot standby server	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	By default, PostgreSQL opens and fsyncs each data file in the database cluster at the start of crash recovery. A new setting, recovery_init_sync_method=syncfs, instead syncs each filesystem used by the cluster. This allows for faster recovery on systems with many database files	Thomas Munro
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	Previously these functions could only be executed by superusers, and this is still the default	Martín Marqués

Streaming replication and recovery – logical replication

Change	Additional informations	Autor/Autorzy
Allow logical replication to stream long in-progress transactions to subscribers	Previously transactions that exceeded logical_decoding_work_mem were written to disk until the transaction completed	Dilip Kumar, Amit Kapila, Ajin Cherian, Tomas Vondra, Nikhil Sontakke, Stas Kelvich
Enhance the logical replication API to allow streaming large in-progress transactions	The output functions begin with stream. test_decoding also supports these	Tomas Vondra, Dilip Kumar, Amit Kapila
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	This is useful for logical decoding	Tomas Vondra, Dilip Kumar, Amit Kapila
Enhance logical decoding APIs to handle two-phase commits	This is controlled via pg_create_logical_replication_slot()	Ajin Cherian, Amit Kapila, Nikhil Sontakke, Stas Kelvich
Generate WAL invalidation messages during command completion when using logical replication	When logical replication is disabled, WAL invalidation messages are generated at transaction completion. This allows logical streaming of in-progress transactions	Dilip Kumar, Tomas Vondra, Amit Kapila
Allow logical decoding to more efficiently process cache invalidation messages	This allows logical decoding to work efficiently in presence of a large amount of DDL	Dilip Kumar
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	This is faster than text mode, but slightly less robust	Dave Cramer
Allow logical decoding to be filtered by XID	–	Markus Wanner

SELECT, INSERT

Change	Additional informations	Author(s)
Reduce the number of keywords that can’t be used as column labels without AS	There are now 90% fewer restricted keywords	Mark Dilger
Allow an alias to be specified for JOIN’s USING clause	The alias is created by writing AS after the USING clause. It can be used as a table qualification for the merged USING columns	Peter Eisentraut
Allow DISTINCT to be added to GROUP BY to remove duplicate GROUPING SET combinations	For example, GROUP BY CUBE (a,b), CUBE (b,c) will generate duplicate grouping combinations without DISTINCT	Vik Fearing
Properly handle DEFAULT entries in multi-row VALUES lists in INSERT	Such cases used to throw an error.	Dean Rasheed
Add SQL-standard SEARCH and CYCLE clauses for common table expressions	The same results could be accomplished using existing syntax, but much less conveniently	Peter Eisentraut
Allow column names in the WHERE clause of ON CONFLICT to be table-qualified	Only the target table can be referenced, however	Tom Lane

Utility commands

Change	Additional informations	Author(s)
Allow REFRESH MATERIALIZED VIEW to use parallelism	–	Bharath Rupireddy
Allow REINDEX to change the tablespace of the new index	This is done by specifying a TABLESPACE clause. A –tablespace option was also added to reindexdb to control this	Alexey Kondratov, Michael Paquier, Justin Pryzby
Allow REINDEX to process all child tables or indexes of a partitioned relation	–	Justin Pryzby, Michael Paquier
Allow index commands using CONCURRENTLY to avoid waiting for the completion of other operations using CONCURRENTLY	–	Álvaro Herrera
Improve the performance of COPY FROM in binary mode	–	Bharath Rupireddy, Amit Langote
Preserve SQL standard syntax for SQL-defined functions in view definitions	Previously, calls to SQL-standard functions such as EXTRACT() were shown in plain function-call syntax. The original syntax is now preserved when displaying a view or rule	Tom Lane
Add the SQL-standard clause GRANTED BY to GRANT and REVOKE	–	Peter Eisentraut
Add OR REPLACE option for CREATE TRIGGER	This allows pre-existing triggers to be conditionally replaced	Takamichi Osumi
Allow TRUNCATE to operate on foreign tables	The postgres_fdw module also now supports this	Kazutaka Onishi, Kohei KaiGai
Allow publications to be more easily added to and removed from a subscription	The new syntax is ALTER SUBSCRIPTION … ADD/DROP PUBLICATION. This avoids having to specify all publications to add/remove entries	Japin Li
Add primary keys, unique constraints, and foreign keys to system catalogs	These changes help GUI tools analyze the system catalogs. The existing unique indexes of catalogs now have associated UNIQUE or PRIMARY KEY constraints. Foreign key relationships are not actually stored or implemented as constraints, but can be obtained for display from the function pg_get_catalog_foreign_keys()	Peter Eisentraut
Allow CURRENT_ROLE every place CURRENT_USER is accepted	–	Peter Eisentraut

Data types

Change	Additional informations	Author(s)
Allow extensions and built-in data types to implement subscripting	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	Dmitry Dolgov
Allow subscripting of JSONB	JSONB subscripting can be used to extract and assign to portions of JSONB documents	Dmitry Dolgov
Add support for multirange data types	These are like range data types, but they allow the specification of multiple, ordered, non-overlapping ranges. An associated multirange type is automatically created for every range type	Paul Jungwirth, Alexander Korotkov
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	The previous limit was 4K bytes. Also remove function t_readline()	Tom Lane
Add support for Infinity and -Infinity values in the numeric data type	Floating-point data types already supported these	Tom Lane
Add point operators <<| and |>> representing strictly above/below tests	Previously these were called >^ and <^, but that naming is inconsistent with other geometric data types. The old names remain available, but may someday be removed	Emre Hasegeli
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 system catalogs	User-defined relations have long had composite types associated with them, and also array types over those composite types. System catalogs now do as well. This change also fixes an inconsistency that creating a user-defined table in single-user mode would fail to create a composite array type	Wenjing Zeng

Functions

Change	Additional informations	Author(s)
Allow SQL-language functions and procedures to use SQL-standard function bodies	Previously only string-literal function bodies were supported. When writing a function or procedure in SQL-standard syntax, the body is parsed immediately and stored as a parse tree. This allows better tracking of function dependencies, and can have security benefits	Peter Eisentraut
Allow procedures to have OUT parameters	–	Peter Eisentraut
Allow some array functions to operate on a mix of compatible data types	The functions array_append(), array_prepend(), array_cat(), array_position(), array_positions(), array_remove(), array_replace(), and width_bucket() now take anycompatiblearray instead of anyarray arguments. This makes them less fussy about exact matches of argument types	Tom Lane
Add SQL-standard trim_array() function	This could already be done with array slices, but less easily	Fearing
Add bytea equivalents of ltrim() and rtrim()	–	Joel Jacobson
Support negative indexes in split_part()	Negative values start from the last field and count backward	Nikhil Benesch
Add string_to_table() function to split a string on delimiters	This is similar to the regexp_split_to_table() function	Pavel Stehule
Add unistr() function to allow Unicode characters to be specified as backslash-hex escapes in strings	This is similar to how Unicode can be specified in literal strings	Pavel Stehule
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	This function “bins” input timestamps, grouping them into intervals of a uniform length aligned with a specified origin	John Naylor
Allow make_timestamp()/make_timestamptz() to accept negative years	Negative values are interpreted as BC years	Peter Eisentraut
Add newer regular expression substring() syntax	The new SQL-standard syntax is SUBSTRING(text SIMILAR pattern ESCAPE escapechar). The previous standard syntax was SUBSTRING(text FROM pattern FOR escapechar), which is still accepted by PostgreSQL	Peter Eisentraut
Allow complemented character class escapes , , and within regular expression brackets	–	Tom Lane
Add [[:word:]] as a regular expression character class, equivalent to	–	Tom Lane
Allow more flexible data types for default values of lead() and lag() window functions	–	Vik Fearing
Make non-zero floating-point values divided by infinity return zero	Previously such operations produced underflow errors	Kyotaro Horiguchi
Make floating-point division of NaN by zero return NaN	Previously this returned an error	Tom Lane
Cause exp() and power() for negative-infinity exponents to return zero	Previously they often returned underflow errors	Tom Lane
Improve the accuracy of geometric computations involving infinity	–	Tom Lane
Mark built-in type coercion functions as leakproof where possible	This allows more use of functions that require type conversion in security-sensitive situations	Tom Lane
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

PL/pgSQL

Change	Additional informations	Autor/Autorzy
Improve PL/pgSQL’s expression and assignment parsing	This change allows assignment to array slices and nested record fields	Tom Lane
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

Client interfaces

Change	Additional informations	Author(s)
Add pipeline mode to libpq	This allows multiple queries to be sent, only waiting for completion when a specific synchronization message is sent	Craig Ringer, Matthieu Garrigues, Álvaro Herrera
Enhance libpq’s target_session_attrs parameter options	The new options are read-only, primary, standby, and prefer-standby	Haribabu Kommi, Greg Nancarrow, Vignesh C, Tom Lane
Improve the output format of libpq’s PQtrace()	–	Aya Iwata, Álvaro Herrera
Allow an ECPG SQL identifier to be linked to a specific connection	This is done via DECLARE … STATEMENT	Hayato Kuroda

Client applications

Change	Additional informations	Author(s)
Allow vacuumdb to skip index cleanup and truncation	The options are –no-index-cleanup and –no-truncate	Nathan Bossart
Allow pg_dump to dump only certain extensions	This is controlled by option –extension	Guillaume Lelarge
Add pgbench permute() function to randomly shuffle values	–	Fabien Coelho, Hironobu Suzuki, Dean Rasheed
Include disconnection times in the reconnection overhead measured by pgbench with -C	–	Yugo Nagata
Allow multiple verbose option specifications (-v) to increase the logging verbosity	This behavior is supported by pg_dump, pg_dumpall, and pg_restore	Tom Lane

Client applications – psql

Change	Additional informations	Autor/Autorzy
Allow psql’s and commands to specify function and operator argument types	This helps reduce the number of matches printed for overloaded names	Greg Sabino Mullane, Tom Lane
Add an access method column to psql’s + output	–	Georgios Kokolatos
Allow psql’s and to show TOAST tables and their indexes	–	Justin Pryzby
Add psql command to list extended statistics objects	–	Tatsuro Yamada
Fix psql’s 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 , or using and , ignore the results if the editor exits without saving	Previously, such edits would load the previous query into the query buffer, and typically execute it immediately. This was deemed to be probably not what the user wants	Laurenz Albe
Improve tab completion	–	Vignesh C, Michael Paquier, Justin Pryzby, Georgios Kokolatos, Julien Rouhaud

 Server applications

Change	Additional informations	Author(s)
Add command-line utility pg_amcheck to simplify running contrib/amcheck tests on many relations	–	Mark Dilger
Add –no-instructions option to initdb	This suppresses the server startup instructions that are normally printed	Magnus Hagander
Stop pg_upgrade from creating analyze_new_cluster script	Instead, give comparable vacuumdb instructions	Magnus Hagander
Remove support for the postmaster -o option	This option was unnecessary since all passed options could already be specified directly	Magnus Hagander

 Documentation

Change	Additional informations	Author(s)
Rename “Default Roles” to “Predefined Roles”	–	Bruce Momjian, Stephen Frost
Add documentation for the factorial() function	With the removal of the ! operator in this release, factorial() is the only built-in way to compute a factorial	Peter Eisentraut

 Source code

Change	Additional informations	Autor/Autorzy
Add configure option –with-ssl={openssl} to allow future choice of the SSL library to use	The spelling –with-openssl is kept for compatibility	Daniel Gustafsson, Michael Paquier
Add support for abstract Unix-domain sockets	This is currently supported on Linux and Windows	Peter Eisentraut
Allow Windows to properly handle files larger than four gigabytes	For example this allows COPY, WAL files, and relation segment files to be larger than four gigabytes	Juan José Santamaría Flecha
Add server parameter debug_discard_caches to control cache flushing for test purposes	Previously this behavior could only be set at compile time. To invoke it during initdb, use the new option –discard-caches	Craig Ringer
Various improvements in valgrind error detection ability	–	Álvaro Herrera, Peter Geoghegan
Add a test module for the regular expression package	–	Tom Lane
Add support for LLVM version 12	–	Andres Freund
Change SHA1, SHA2, and MD5 hash computations to use the OpenSSL EVP API	This is more modern and supports FIPS mode	Michael Paquier
Remove separate build-time control over the choice of random number generator	This is now always determined by the choice of SSL library	Daniel Gustafsson
Add direct conversion routines between EUC_TW and Big5 encodings	–	Heikki Linnakangas
Add collation version support for FreeBSD	–	Thomas Munro
Add amadjustmembers to the index access method API	This allows an index access method to provide validity checking during creation of a new operator class or family	Tom Lane
Provide feature-test macros in libpq-fe.h for recently-added libpq features	Historically, applications have usually used compile-time checks of PG_VERSION_NUM to test whether a feature is available. But that’s normally the server version, which might not be a good guide to libpq’s version. libpq-fe.h now offers #define symbols denoting application-visible features added in v14; the intent is to keep adding symbols for such features in future versions	Tom Lane, Álvaro Herrera

 Additional modules

Change	Additional informations	Author(s)
Allow subscripting of hstore values	–	Tom Lane, Dmitry Dolgov
Allow GiST/GIN pg_trgm indexes to do equality lookups	This is similar to LIKE except no wildcards are honored	Julien Rouhaud
Allow the cube data type to be transferred in binary mode	–	KaiGai Kohei
Allow pgstattuple_approx() to report on TOAST tables	–	Peter Eisentraut
Add contrib module pg_surgery which allows changes to row visibility	This is useful for correcting database corruption	Ashutosh Sharma
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	Previously it only checked B-Tree index pages	Mark Dilger
Allow pageinspect to inspect GiST indexes	–	Andrey Borodin, Heikki Linnakangas
Change pageinspect block numbers to be bigints	–	Peter Eisentraut
Mark btree_gist functions as parallel safe	–	Steven Winfield

 Additional modules – pg_stat_statements

Change	Additional informations	Author(s)
Move query hash computation from pg_stat_statements to the core server	The new server parameter compute_query_id’s default of auto will automatically enable query id computation when this extension is loaded	Julien Rouhaud
Cause pg_stat_statements to track top and nested statements separately	Previously, when tracking all statements, identical top and nested statements were tracked as a single entry; but it seems more useful to separate such usages	Julien Rohaud
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

 Additional modules –  postgres_fdw

Change	Additional informations	Author(s)
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	By default, only the root of a partitioned table is imported	Matthias van de Meent
Add postgres_fdw function postgres_fdw_get_connections() to report open foreign server connections	–	Bharath Rupireddy
Allow control over whether foreign servers keep connections open after transaction completion	This is controlled by keep_connections and defaults to on	Bharath Rupireddy
Allow postgres_fdw to reestablish foreign server connections if necessary	Previously foreign server restarts could cause foreign table access errors	Bharath Rupireddy
Add postgres_fdw functions to discard cached connections	–	Bharath Rupireddy

Further development

The above list of new features in PostgreSQL shows constant development and commitment of many communities, whose goal is to create the best, the fastest and always free database engine. We will be happy to follow Postgres development and keep you informed of any news.