PostgreSQL 16

PostgreSQL 16 is the future development version of PostgreSQL, likely to be released in late 2023.

Initial commit marking the start of PostgreSQL 16 development is d31d3097 (2022-06-30).

CommitFests

Following CommitFests are for PostgreSQL 16 code submissions:

• CommitFest 42 (2023-03-01 - 2023-03-31; future)
• CommitFest 41 (2023-01-01 - 2023-01-31; in progress)
• CommitFest 40 (2022-11-01 - 2022-11-30; closed)
• CommitFest 39 (2022-09-01 - 2022-09-30; closed)
• CommitFest 38 (2022-07-01 - 2022-07-31; closed)

Note that the last CommitFest (March 2023) generally stays open a few days beyond the official end date until feature freeze is announced, usually in early April.

Backend changes

Build system

• support for Meson build system added (initial commit e6927270)

Source configuration

• segment size can be specified in blocks (commit d3b111e3)

Materialized views

• materialized views participate in predicate locking (commit 43351557)

postmaster

• option -n removed (commit 51b5834c)
• option -T now sents SIGABRT rather than SIGSTOP (commit 51b5834c)

WAL

• freeze plans in freeze WAL records deduplicated (commit 9e540599)

walreceiver

• wakeup intervals made more targetted towards actual pending work (commit 05a7be93)

walsender

• database name shown in ps display (commit af205152)

Performance improvements

• performance of ORDER BY / DISTINCT aggregates improved (commit 1349d279)
• bulk inserts and updates on partitioned tables made more efficient (commit 3592e0ff)
• lookup in snapshots optimized (commits 37a6e5df, b6ef1675 and 82739d4a)
• performance of string-to-integer conversion improved (commit 6b423ec6)

Data type changes

General:

• support for binary, octal and hexadecimal integer literals added (commit 6fcda9ab)
• +infinity now accepted for input with date and timestamp types (commit 2ceea5ad)

Indexing changes

Hash indexes

• speed of hash index builds improved (commit e09d7a12)

SQL changes

General:

• FROM clause subquery aliases no longer required (commit bcedd8f5)
• SYSTEM_USER reserved keyword now supported (commit 0823d061)

Modified:

• ALTER DATABASE
  • ALTER DATABASE ... SET ... { TO | = } value USER SET syntax added (commit 096dd80f)
• ALTER DEFAULT PRIVILEGES
  • now requires privileges instead of membership (commit 48a257d4)
• ALTER ROLE
  • ALTER ROLE ... SET ... { TO | = } value USER SET syntax added (commit 096dd80f)
• ALTER TABLE
  • SET STORAGE DEFAULT syntax added (commit b9424d01)
• ALTER USER
  • ALTER USER ... SET ... { TO | = } value USER SET syntax added (commit 096dd80f)
• COPY
  • batch insertion into foreign tables enabled (commit 97da4824)
• CREATE STATISTICS
  • the statistics name is now optional (commit 624aa2a1)
• CREATE SUBSCRIPTION
  • parameter origin added (commit 36628396)
• CREATE TABLE
  • CREATE TABLE ... STORAGE ... syntax added (commit 784cedda)
• GRANT
  • WITH SET option added (commit 3d14e171)
  • VACUUM and ANALYZE privileges added (commit b5d63824)
  • MAINTAIN privilege added (commit 60684dd8)
• REINDEX
  • database name no longer mandatory (commit 2cbc3c17)
  • system catalog tables will only be reindexed with REINDEX SYSTEM (commit 2cbc3c17)
• VACUUM
  • options SKIP_DATABASE_STATS and ONLY_DATABASE_STATS added (commit a46a7011)

System catalog changes

Tables

Modified:

• pg_auth_members
  • column set_option added (commit 3d14e171)
• pg_class
  • type of column relfilenode changed from oid to int8 (commit 05d4cbf9)
• pg_db_role_setting]
  • column setuser added (commit 096dd80f)

Views

Modified:

• pg_stat_all_tables
  • column last_seq_scan added (commit c0374718)
• pg_stat_subscription
  • column leader_pid addedd540a02a)

System function changes

Added:

• pg_input_error_message() (commit 1939d262)
• pg_input_is_valid() (commit 1939d262)
• pg_split_walfile_name() (commit cca18634)
• pg_stat_get_backend_subxact() (commit 10ea0f92)
• random_normal() (commit 38d81760)

Modified:

• array_agg()
  • parallel aggregation support added (commit 16fd03e9)
• pg_collation_actual_version()
  • made effective with the default collation instead of returning NULL (commit 10932ed5)
• pg_import_system_collations()
  • Windows support added (commit bf03cfd1)
• pg_read_file()
  • can be called as pg_read_file ( filename text, missing_ok boolean ) (commit 283129e3)
• pg_stat_get_backend_idset()
  • returns actual backend IDs (commit d7e39d72)
• power()
  • accuracy of numeric power() for integer exponents improved (commit 40c7fcbb)
• array_agg()
  • parallel aggregation support added (commit 16fd03e9)
• to_regclass()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regcollation()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regnamespace()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regoper()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regoperator()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regproc()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regprocedure()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regrole()
  • able to accept numeric OID input (commit 3ea7329c)
• to_regtype()
  • able to accept numeric OID input (commit 3ea7329c)

Configuration changes

General:

• GUC infrastructure modernized and made more efficient (commits f13b2088, 3057465a, 407b50f2, 9c911ec0)
• GUC_NO_RESET flag added (commit 38536642)

Added:

• createrole_self_grant (commit e5b8a4c0)
• enable_presorted_aggregate (commit 3226f472)
• logical_decoding_mode (commit 5de94a04)
• max_parallel_apply_workers_per_subscription (commit 216a7848)
• reserved_connections (commit 6e2775e4)
• send_abort_for_crash (commit 51b5834c)
• send_abort_for_kill (commit 51b5834c)
• vacuum_freeze_strategy_threshold (commit 4d417992) reverted in 6c6b4972

Modified:

• archive_command
  • may no longer be set at the same time as archive_library (commit d627ce3b)
• archive_library
  • may no longer be set at the same time as archive_command (commit d627ce3b)
• shared_preload_libraries
  • now processed in single-user mode (commit 6c31ac09)
• wal_sync_method
  • fdatasync option now supported on Windows (commit 9430fb40)

Removed:

• promote_trigger_file (commit cd4329d9)

Platform support changes

HP/Intel Itanium

• support removed (commit 0ad5b48e)

HP-UX

• port removed (commit 9db300ce)

Windows

• support removed for versions older than Windows 10 (commit 495ed0ef)

Indexing changes

• hash index build speed improved (commit d09dbeb9)

Logging changes

• internal log_status_format() added for use by emit_log_hook etc. (commit b40baa96)
• checkpoint and recovery point LSNs displayed in LogCheckpointEnd log message (commit 62c46eee)
• autovacuum log output and VACUUM VERBOSE output now include a line containing the total number of heap pages which had one or more tuples frozen, and the total number of tuples frozen (commit d977ffd9)
• LSN now included in some error messages related to WAL pages (commit 71cb84ec)

Users / roles

• superuser privileges can no longer be removed from the bootstrap user (commit e530be2c)
• pg_maintain predefined role added (commit 60684dd8)
• pg_use_reserved_connections predefined role added (commit 6e2775e4)
• users with the CREATEROLE attribute restricted to asdministrating roles they created or have been granted privileges on (cpmmit cf5eb37c)

Authentication changes

pg_hba.conf

• regular expressions (regexp) support added for database and user entries (commit 8fea8683)
• support for file inclusion added (commit a54b658c)

pg_ident.conf

• support for file inclusion added (commit a54b658c)

Procedural language changes

PL/pgSQL

• bound cursor variables no longer have a preassigned portal name (commit d747dc85)

Replication changes

Logical replication

• publications can include both a schema and individual tables from the same schema (commit 13a185f5)
• logical replication of data with an origin can be skipped (commit 36628396)
• large transactions applied by parallel workers (commit 216a7848)

Foreign data wrapper changes

• TRUNCATE triggers on foreign tables now permitted (commit 3b00a944)

Core utilities

Modified:

• createuser
  • following options added (commit 08951a7c):
    • -a/--admin
    • --bypassrls/--no-bypassrls
    • -m/--member
    • --valid-until
• pg_dump
  • -Z/--compress option can now specify the compression method (commit 5e73a604)
  • locks now acquired in batches during startup (commit 5f53b42c)
• vacuumdb
  • options --schema and --exclude-schema added (commit 7781f4e3)

Server utilities

Modified:

• pg_upgrade
  • option --copy added (commit 746915c6
• pg_waldump
  • option --save-fullpage added (commit d497093c)

psql

• \pset option xheader_width added (commit a45388d6)
• \d+ on a partitioned table now indicates foreign partitions (commit bd95816f)
• \bind command added for setting query parameters and using the extended query protocol (commit 5b66de34)
• \dpS and \zS commands added (commit d913928c)

Contrib module changes

auto_explain

• option auto_explain.log_parameter_max_length added (commit d4bfe412)

ltree

• maximum label length extended to 1000 characters and labels may contain hyphens (commit b1665bf0)

pageinspect

• function bt_multi_page_stats() added (commit 1fd3dd20)

pg_buffercache

• function pg_buffercache_summary() added (commit 2589434a)

pg_walinspect

• function pg_get_wal_fpi_info() added (commit c31cf1c0)

postgres_fdw

• data returned for ANALYZE can be extracted using table sampling (commit 8ad51b5f)
• option analyze_sampling added (commit 8ad51b5f)