Release date: 2019-10-03
Major enhancements in PostgreSQL 12 include:
General performance improvements, including:
Optimizations to space utilization and read/write performance for B-tree indexes
Partitioning performance enhancements, including improved query
performance on tables with thousands of partitions, improved
insertion performance with INSERT and COPY, and the ability to execute ALTER TABLE ATTACH
PARTITION without blocking queries
Automatic (but overridable) inlining of common table expressions (CTEs)
Reduction of WAL overhead for creation of GiST, GIN, and SP-GiST indexes
Multi-column most-common-value (MCV) statistics can be defined via CREATE STATISTICS, to support better plans for queries that test several non-uniformly-distributed columns
Enhancements to administrative functionality, including:
REINDEX
CONCURRENTLY can rebuild an index without
blocking writes to its table
pg_checksums can enable/disable page checksums (used for detecting data corruption) in an offline cluster
Progress reporting statistics for CREATE INDEX, REINDEX, CLUSTER, VACUUM FULL, and pg_checksums
Support for the SQL/JSON path language
Stored generated columns
Nondeterministic ICU collations, enabling case-insensitive and accent-insensitive grouping and ordering
New authentication features, including:
Encryption of TCP/IP connections when using GSSAPI authentication
Discovery of LDAP servers using DNS SRV records
Multi-factor authentication, using the
clientcert=verify-full option combined
with an additional authentication method in
pg_hba.conf
The above items are explained in more detail in the sections below.
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 18.6 for general information on migrating to new major releases.
Version 12 contains a number of changes that may affect compatibility with previous releases. Observe the following incompatibilities:
Remove the special behavior of oid columns (Andres Freund, John Naylor) §
Previously, a normally-invisible oid
column could be specified during table creation using WITH
OIDS; that ability has been removed. Columns can still be
explicitly declared as type oid. Operations on tables
that have columns created using WITH OIDS will
need adjustment.
The system catalogs that previously had
hidden oid columns now have
ordinary oid columns.
Hence, SELECT * will now output those columns,
whereas previously they would be displayed only if selected
explicitly.
Remove data types abstime, reltime,
and tinterval (Andres Freund)
§
These are obsoleted by SQL-standard types such
as timestamp.
Remove the timetravel extension
(Andres Freund)
§
Move recovery.conf settings into postgresql.conf
(Masao Fujii, Simon Riggs, Abhijit Menon-Sen, Sergei Kornilov)
§
recovery.conf is no longer used,
and the server will not start if that file exists. recovery.signal
and standby.signal files are now used to switch
into non-primary mode. The trigger_file setting
has been renamed to promote_trigger_file. The
standby_mode setting has been removed.
Do not allow multiple conflicting recovery_target*
specifications (Peter Eisentraut)
§
Specifically, only allow one of recovery_target, recovery_target_lsn, recovery_target_name, recovery_target_time, and recovery_target_xid. Previously, multiple different instances of these parameters could be specified, and the last one was honored. Now, only one can be specified, though the same one can be specified multiple times and the last specification is honored.
Cause recovery to advance to the latest timeline by default (Peter Eisentraut) §
Specifically, recovery_target_timeline now
defaults to latest. Previously, it defaulted
to current.
Refactor code for geometric functions and operators (Emre Hasegeli) § § §
This could lead to more accurate, but slightly different, results compared to previous releases. Notably, cases involving NaN, underflow, overflow, and division by zero are handled more consistently than before.
Improve performance by using a new algorithm for output
of real
and double precision values (Andrew Gierth)
§
§
Previously, displayed floating-point values were rounded to 6
(for real) or 15 (for double precision)
digits by default, adjusted by the value of
extra_float_digits. Now,
whenever extra_float_digits is more than zero (as
it now is by default), only the minimum number of digits required to
preserve the exact binary value are output. The behavior is the
same as before when extra_float_digits is set to
zero or less.
Also, formatting of floating-point exponents is now uniform across platforms: two digits are used unless three are necessary. In previous releases, Windows builds always printed three digits.
random()
and setseed() now behave uniformly across
platforms (Tom Lane)
§
§
The sequence of random() values generated
following a setseed() call with a particular
seed value is likely to be different now than before. However, it
will also be repeatable, which was not previously guaranteed because
of interference from other uses of random numbers inside the server.
The SQL random() function now has its own
private per-session state to forestall that.
Change SQL-style
substring()
to have standard-compliant greediness behavior (Tom Lane)
§
In cases where the pattern can be matched in more than one way, the
initial sub-pattern is now treated as matching the least possible
amount of text rather than the greatest; for example, a pattern such
as %#"aa*#"% now selects the first group
of a's from the input, not the last group.
Do not pretty-print the result
of xpath()
or the XMLTABLE construct (Tom Lane)
§
In some cases, these functions would insert extra whitespace (newlines and/or spaces) in nodeset values. This is undesirable since depending on usage, the whitespace might be considered semantically significant.
Rename command-line tool pg_verify_checksums to pg_checksums (Michaël Paquier) §
In pg_restore, require specification of
-f - to send the dump contents to standard output
(Euler Taveira)
§
Previously, this happened by default if no destination was specified, but that was deemed to be unfriendly.
Disallow non-unique abbreviations
in psql's \pset format
command (Daniel Vérité)
§
§
Previously, for example, \pset format a chose
aligned; it will now fail since that could
equally well mean asciidoc.
In new btree indexes, the maximum index entry length is reduced by eight bytes, to improve handling of duplicate entries (Peter Geoghegan) §
This means that a REINDEX operation on an index pg_upgrade'd from a previous release could potentially fail.
Cause DROP IF EXISTS
FUNCTION/PROCEDURE/AGGREGATE/ROUTINE
to generate an error if no argument list is supplied and there are
multiple matching objects (David Rowley)
§
Also improve the error message in such cases.
Split the pg_statistic_ext
catalog into two catalogs, and add the pg_stats_ext
view of it (Dean Rasheed, Tomas Vondra)
§
§
This change supports hiding potentially-sensitive statistics data from unprivileged users.
Remove obsolete pg_constraint.consrc
column (Peter Eisentraut)
§
This column has been deprecated for a long time, because it did not
update in response to other catalog changes (such as column renamings).
The recommended way to get a text version of a check constraint's
expression from pg_constraint
is pg_get_expr(conbin, conrelid).
pg_get_constraintdef() is also a useful
alternative.
Remove obsolete pg_attrdef.adsrc
column (Peter Eisentraut)
§
This column has been deprecated for a long time, because it did not
update in response to other catalog changes (such as column renamings).
The recommended way to get a text version of a default-value expression
from pg_attrdef is pg_get_expr(adbin,
adrelid).
Mark table columns of type name as having “C” collation by default (Tom Lane, Daniel Vérité) § §
The comparison operators for data type name can now use
any collation, rather than always using “C” collation.
To preserve the previous semantics of queries, columns of
type name are now explicitly marked as
having “C” collation. A side effect of this is that
regular-expression operators on name columns will now
use the “C” collation by default, not the database
collation, to determine the behavior of locale-dependent regular
expression patterns (such as \w). If you want
non-C behavior for a regular expression on a name
column, attach an explicit COLLATE clause. (For
user-defined name columns, another possibility is to
specify a different collation at table creation time; but that just
moves the non-backwards-compatibility to the comparison operators.)
Treat object-name columns in
the information_schema
views as being of type name, not varchar
(Tom Lane)
§
§
§
Per the SQL standard, object-name columns in
the information_schema views are declared
as being of domain type sql_identifier.
In PostgreSQL, the underlying catalog
columns are really of type name. This change
makes sql_identifier be a domain
over name, rather than varchar as before.
This eliminates a semantic mismatch in comparison and sorting
behavior, which can greatly improve the performance of queries
on information_schema views that restrict
an object-name column. Note however that inequality restrictions,
for example
SELECT ... FROM information_schema.tables WHERE table_name < 'foo';
will now use “C”-locale comparison semantics by
default, rather than the database's default collation as before.
Sorting on these columns will also follow “C” ordering
rules. The previous behavior (and inefficiency) can be enforced by
adding a COLLATE "default" clause.
Remove the ability to disable dynamic shared memory (Kyotaro Horiguchi) §
Specifically, dynamic_shared_memory_type
can no longer be set to none.
Parse libpq integer connection parameters more strictly (Fabien Coelho) §
In previous releases, using an incorrect integer value for
connection parameters connect_timeout,
keepalives, keepalives_count,
keepalives_idle,
keepalives_interval and port
resulted in libpq either ignoring those values or failing with
incorrect error messages.
Below you will find a detailed account of the changes between PostgreSQL 12 and the previous major release.
Improve performance of many operations on partitioned tables (Amit Langote, David Rowley, Tom Lane, Álvaro Herrera) § § § § §
Allow tables with thousands of child partitions to be processed efficiently by operations that only affect a small number of partitions.
Allow foreign keys to reference partitioned tables (Álvaro Herrera) §
Improve speed of COPY into partitioned tables
(David Rowley)
§
Allow partition bounds to be any expression (Kyotaro Horiguchi, Tom Lane, Amit Langote) §
Such expressions are evaluated at partitioned-table creation time. Previously, only simple constants were allowed as partition bounds.
Allow CREATE TABLE's tablespace specification
for a partitioned table to affect the tablespace of its children
(David Rowley, Álvaro Herrera)
§
Avoid sorting when partitions are already being scanned in the necessary order (David Rowley) §
ALTER TABLE ATTACH
PARTITION is now performed with reduced locking
requirements (Robert Haas)
§
Add partition introspection functions (Michaël Paquier, Álvaro Herrera, Amit Langote) § § §
The new function pg_partition_root()
returns the top-most parent of a partition tree, pg_partition_ancestors()
reports all ancestors of a partition, and pg_partition_tree()
displays information about partitions.
Include partitioned indexes in the system view pg_indexes
(Suraj Kharage)
§
Add psql command \dP
to list partitioned tables and indexes (Pavel Stehule)
§
Improve psql \d
and \z display of partitioned tables (Pavel
Stehule, Michaël Paquier, Álvaro Herrera)
§
§
§
Fix bugs that could cause ALTER TABLE DETACH
PARTITION to leave behind incorrect dependency state,
allowing subsequent operations to misbehave, for example by not
dropping a former partition child index when its table is dropped
(Tom Lane)
§
Improve performance and space utilization of btree indexes with many duplicates (Peter Geoghegan, Heikki Linnakangas) § § §
Previously, duplicate index entries were stored unordered within
their duplicate groups. This caused overhead during index
inserts, wasted space due to excessive page splits, and it reduced
VACUUM's ability to recycle entire pages.
Duplicate index entries are now sorted in heap-storage order.
Indexes pg_upgrade'd from previous releases will not have these benefits.
Allow multi-column btree indexes to be smaller (Peter Geoghegan, Heikki Linnakangas)
Internal pages and min/max leaf page indicators now only store index keys until the change key, rather than all indexed keys. This also improves the locality of index access.
Indexes pg_upgrade'd from previous releases will not have these benefits.
Improve speed of btree index insertions by reducing locking overhead (Alexander Korotkov) §
Add support for nearest-neighbor (KNN) searches of SP-GiST indexes (Nikita Glukhov, Alexander Korotkov, Vlad Sterzhanov) §
Reduce the WAL write overhead of GiST, GIN, and SP-GiST index creation (Anastasia Lubennikova, Andrey V. Lepikhov) §
Allow index-only scans to be more efficient on indexes with many columns (Konstantin Knizhnik) §
Improve the performance of vacuum scans of GiST indexes (Andrey Borodin, Konstantin Kuznetsov, Heikki Linnakangas) §
Delete empty leaf pages during GiST
VACUUM (Andrey Borodin)
§
Reduce locking requirements for index renaming (Peter Eisentraut) §
Allow CREATE STATISTICS to create most-common-value statistics for multiple columns (Tomas Vondra) § §
This improves optimization for queries that test several columns,
requiring an estimate of the combined effect of
several WHERE clauses. If the columns are
correlated and have non-uniform distributions then multi-column
statistics will allow much better estimates.
Allow common table expressions (CTEs) to be inlined into the outer query (Andreas Karlsson, Andrew Gierth, David Fetter, Tom Lane) § §
Specifically, CTEs are automatically inlined if
they have no side-effects, are not recursive, and are referenced
only once in the query. Inlining can be prevented by
specifying MATERIALIZED, or forced for
multiply-referenced CTEs by
specifying NOT MATERIALIZED. Previously,
CTEs were never inlined and were always
evaluated before the rest of the query.
Allow control over when generic plans are used for prepared statements (Pavel Stehule) §
This is controlled by the plan_cache_mode server parameter.
Improve optimization of partition and UNION ALL
queries that have only a single child (David Rowley)
§
Improve processing of domains that have no check constraints (Tom Lane) §
Domains that are being used purely as type aliases no longer cause optimization difficulties.
Pre-evaluate calls of LEAST
and GREATEST when their arguments are constants
(Vik Fearing)
§
Improve optimizer's ability to verify that partial indexes
with IS NOT NULL conditions are usable in
queries (Tom Lane, James Coleman)
§
§
Usability can now be recognized in more cases where the calling
query involves casts or
large x IN
(array)
Compute ANALYZE statistics using the collation
defined for each column (Tom Lane)
§
Previously, the database's default collation was used for all statistics. This potentially gives better optimizer behavior for columns with non-default collations.
Improve selectivity estimates for inequality comparisons
on ctid
columns (Edmund Horner)
§
Improve optimization of joins on columns of type tid
(Tom Lane)
§
§
These changes primarily improve the efficiency of self-joins
on ctid columns.
Fix the leakproofness designations of some btree comparison operators and support functions (Tom Lane) § §
This allows some optimizations that previously would not have been applied in the presence of security barrier views or row-level security.
Enable Just-in-Time (JIT) compilation by default, if the server has been built with support for it (Andres Freund) §
Note that this support is not built by default, but has to be selected explicitly while configuring the build.
Speed up keyword lookup (John Naylor, Joerg Sonnenberger, Tom Lane) § §
Improve search performance for multi-byte characters
in position() and related functions (Heikki
Linnakangas)
§
Allow toasted values to be minimally decompressed (Paul Ramsey) §
This is useful for routines that only need to examine the initial portion of a toasted field.
Allow ALTER TABLE ... SET
NOT NULL to avoid unnecessary table scans (Sergei
Kornilov)
§
This can be optimized when the table's column constraints can be recognized as disallowing nulls.
Allow ALTER TABLE ... SET DATA TYPE changing between
timestamp and timestamptz to avoid a
table rewrite when the session time zone is UTC
(Noah Misch)
§
In the UTC time zone, these two data types are binary compatible.
Improve speed in converting strings to
int2 or int4 integers (Andres Freund)
§
Allow parallelized queries when in SERIALIZABLE
isolation mode (Thomas Munro)
§
Previously, parallelism was disabled when in this mode.
Use pread() and pwrite()
for random I/O (Oskari Saarenmaa, Thomas Munro)
§
§
This reduces the number of system calls required for I/O.
Improve the speed of setting the process title on FreeBSD (Thomas Munro) §
Allow logging of statements from only a percentage of transactions (Adrien Nayrat) §
The parameter log_transaction_sample_rate controls this.
Add progress reporting to CREATE INDEX and
REINDEX operations (Álvaro Herrera, Peter
Eisentraut)
§
§
Progress is reported in the pg_stat_progress_create_index
system view.
Add progress reporting to CLUSTER and
VACUUM FULL (Tatsuro Yamada)
§
Progress is reported in the pg_stat_progress_cluster
system view.
Add progress reporting to pg_checksums (Michael Banck, Bernd Helmle) §
This is enabled with the option --progress.
Add counter of checksum failures to
pg_stat_database (Magnus Hagander)
§
Add tracking of global objects in system view
pg_stat_database (Julien Rouhaud)
§
Global objects are shown with a pg_stat_database.datid
value of zero.
Add the ability to list the contents of the archive directory (Christoph Moench-Tegeder) §
The function is pg_ls_archive_statusdir().
Add the ability to list the contents of temporary directories (Nathan Bossart) §
The function, pg_ls_tmpdir(),
optionally allows specification of a tablespace.
Add information about the client certificate to the system view pg_stat_ssl
(Peter Eisentraut)
§
The new columns are client_serial
and issuer_dn. Column
clientdn has been renamed to
client_dn for clarity.
Restrict visibility of rows in pg_stat_ssl
for unprivileged users (Peter Eisentraut)
§
At server start, emit a log message including the server version number (Christoph Berg) §
Prevent logging “incomplete startup packet” if a new connection is immediately closed (Tom Lane) §
This avoids log spam from certain forms of monitoring.
Include the application_name, if set, in log_connections log messages (Don Seiler) §
Make the walreceiver set its application name to the cluster name, if set (Peter Eisentraut) §
Add the timestamp of the last received standby message to pg_stat_replication
(Lim Myungkyu)
§
Add a wait event for fsync of WAL segments (Konstantin Knizhnik) §
Add GSSAPI encryption support (Robbie Harwood, Stephen Frost) §
This feature allows TCP/IP connections to be encrypted when using
GSSAPI authentication, without having to set up a separate
encryption facility such as SSL.
In support of this, add hostgssenc
and hostnogssenc record types in pg_hba.conf
for selecting connections that do or do not use GSSAPI encryption,
corresponding to the existing hostssl
and hostnossl record types.
There is also a new gssencmode
libpq option, and a pg_stat_gssapi system
view.
Allow the clientcert
pg_hba.conf option to check that the database
user name matches the client certificate's common name
(Julian Markwort, Marius Timmer)
§
This new check is enabled with
clientcert=verify-full.
Allow discovery of an LDAP server using DNS SRV records (Thomas Munro) §
This avoids the requirement of specifying
ldapserver. It is only supported if
PostgreSQL is compiled with
OpenLDAP.
Add ability to enable/disable cluster checksums using pg_checksums (Michael Banck, Michaël Paquier) §
The cluster must be shut down for these operations.
Reduce the default value of autovacuum_vacuum_cost_delay to 2ms (Tom Lane) §
This allows autovacuum operations to proceed faster by default.
Allow vacuum_cost_delay to specify sub-millisecond delays, by accepting fractional values (Tom Lane) §
Allow time-based server parameters to use units of microseconds
(us) (Tom Lane)
§
Allow fractional input for integer server parameters (Tom Lane) §
For example, SET work_mem = '30.1GB' is now
allowed, even though work_mem is an integer
parameter. The value will be rounded to an integer after any
required units conversion.
Allow units to be defined for floating-point server parameters (Tom Lane) §
Add wal_recycle and wal_init_zero server parameters to control WAL file recycling (Jerry Jelinek) §
Avoiding file recycling can be beneficial on copy-on-write file systems like ZFS.
Add server parameter tcp_user_timeout to control the server's TCP timeout (Ryohei Nagaura) §
Allow control of the minimum and maximum SSL protocol versions (Peter Eisentraut) §
The server parameters are ssl_min_protocol_version and ssl_max_protocol_version.
Add server parameter ssl_library to report the SSL library version used by the server (Peter Eisentraut) §
Add server parameter shared_memory_type to control the type of shared memory to use (Andres Freund) §
This allows selection of System V shared memory, if desired.
Allow some recovery parameters to be changed with reload (Peter Eisentraut) §
These parameters are archive_cleanup_command, promote_trigger_file, recovery_end_command, and recovery_min_apply_delay.
Allow the streaming replication timeout (wal_sender_timeout) to be set per connection (Takayuki Tsunakawa) §
Previously, this could only be set cluster-wide.
Add function pg_promote()
to promote standbys to primaries (Laurenz Albe, Michaël Paquier)
§
§
Previously, this operation was only possible by using pg_ctl or creating a trigger file.
Allow replication slots to be copied (Masahiko Sawada) §
The functions for this are pg_copy_physical_replication_slot()
and pg_copy_logical_replication_slot().
Make max_wal_senders not count as part of max_connections (Alexander Kukushkin) §
Add an explicit value of current for recovery_target_timeline (Peter Eisentraut)
§
Make recovery fail if a two-phase transaction status file is corrupt (Michaël Paquier) §
Previously, a warning was logged and recovery continued, allowing the transaction to be lost.
Add REINDEX CONCURRENTLY
option to allow reindexing without locking out writes (Michaël
Paquier, Andreas Karlsson, Peter Eisentraut)
§
This is also controlled by the reindexdb
application's --concurrently option.
Add support for generated columns (Peter Eisentraut) §
The content of generated columns are computed from expressions
(including references to other columns in the same table)
rather than being specified by INSERT or
UPDATE commands.
Add a WHERE clause
to COPY FROM to
control which rows are accepted (Surafel Temesgen)
§
This provides a simple way to filter incoming data.
Allow enumerated values to be added more flexibly (Andrew Dunstan, Tom Lane, Thomas Munro) §
Previously, ALTER TYPE
... ADD VALUE could not be called in a transaction
block, unless it was part of the same transaction that created the
enumerated type. Now it can be called in a later transaction, so
long as the new enumerated value is not referenced until after it is
committed.
Add commands to end a transaction and start a new one (Peter Eisentraut) §
The commands are COMMIT AND
CHAIN
and ROLLBACK AND
CHAIN.
Add VACUUM and CREATE
TABLE options to prevent VACUUM
from truncating trailing empty pages (Takayuki Tsunakawa)
§
§
These options are vacuum_truncate and
toast.vacuum_truncate. Use of these options
reduces VACUUM's locking requirements, but
prevents returning disk space to the operating system.
Allow VACUUM to skip index cleanup
(Masahiko Sawada)
§
§
This change adds a VACUUM command
option INDEX_CLEANUP as well as a table storage
option vacuum_index_cleanup. Use of this option
reduces the ability to reclaim space and can lead to index bloat,
but it is helpful when the main goal is to freeze old tuples.
Add the ability to skip VACUUM and
ANALYZE operations on tables that cannot be
locked immediately (Nathan Bossart)
§
This option is called SKIP_LOCKED.
Allow VACUUM and ANALYZE
to take optional Boolean argument specifications (Masahiko Sawada)
§
Prevent TRUNCATE,
VACUUM and ANALYZE
from requesting a lock on
tables for which the user lacks permission (Michaël Paquier)
§
§
This prevents unauthorized locking, which could interfere with user queries.
Add EXPLAIN option
SETTINGS to output non-default optimizer
settings (Tomas Vondra)
§
This output can also be obtained when using auto_explain
by setting auto_explain.log_settings.
Add OR REPLACE option to
CREATE AGGREGATE
(Andrew Gierth)
§
Allow modifications of system catalogs' options using ALTER TABLE (Peter Eisentraut) §
Modifications of catalogs' reloptions and
autovacuum settings are now supported. (Setting allow_system_table_mods is still required.)
Use all key columns' names when selecting default constraint names for foreign keys (Peter Eisentraut) §
Previously, only the first column name was included in the constraint name, resulting in ambiguity for multi-column foreign keys.
Update assorted knowledge about Unicode to match Unicode 12.1.0 (Peter Eisentraut) § §
This fixes, for example, cases where psql would misformat output involving combining characters.
Update Snowball stemmer dictionaries with support for new languages (Arthur Zakirov) §
This adds word stemming support for Arabic, Indonesian, Irish, Lithuanian, Nepali, and Tamil to full text search.
Allow creation of collations that report string equality for strings that are not bit-wise equal (Peter Eisentraut) §
This feature supports “nondeterministic” collations that can define case- and accent-agnostic equality comparisons. Thus, for example, a case-insensitive uniqueness constraint on a text column can be made more easily than before. This is only supported for ICU collations.
Add support for ICU collation attributes on older ICU versions (Peter Eisentraut) §
This allows customization of the collation rules in a consistent way across all ICU versions.
Allow data type name to more seamlessly be compared to other text types (Tom Lane) §
Type name now behaves much like a domain over
type text that has default collation “C”.
This allows cross-type comparisons to be processed more efficiently.
Add support for the SQL/JSON path language (Nikita Glukhov, Teodor Sigaev, Alexander Korotkov, Oleg Bartunov, Liudmila Mantrova) § § §
This allows execution of complex queries on JSON
values using an SQL-standard language.
Add support for hyperbolic functions (Lætitia Avrot) §
Also add log10() as an alias for
log(), for standards compliance.
Improve the accuracy of statistical aggregates like variance()
by using more precise algorithms (Dean Rasheed)
§
Allow date_trunc()
to have an additional argument to control the time zone (Vik
Fearing, Tom Lane)
§
This is faster and simpler than using the AT TIME
ZONE clause.
Adjust to_timestamp()/to_date()
functions to be more forgiving of template mismatches (Artur
Zakirov, Alexander Korotkov, Liudmila Mantrova)
§
This new behavior more closely matches the Oracle functions of the same name.
Fix assorted bugs in XML functions (Pavel Stehule, Markus Winand, Chapman Flack) §
Specifically, in XMLTABLE,
xpath(), and xmlexists(),
fix some cases where nothing was output for a node, or an
unexpected error was thrown, or necessary escaping of XML special
characters was omitted.
Allow the BY VALUE clause
in XMLEXISTS and XMLTABLE
(Chapman Flack)
§
This SQL-standard clause has no effect in PostgreSQL's implementation, but it was unnecessarily being rejected.
Prevent current_schema()
and current_schemas() from being run by
parallel workers, as they are not parallel-safe (Michaël Paquier)
§
Allow RECORD and RECORD[] to be used
as column types in a query's column definition list for a table function that is declared
to return RECORD (Elvis Pranskevichus)
§
Allow SQL commands and variables with the same names as those commands to be used in the same PL/pgSQL function (Tom Lane) §
For example, allow a variable called comment to
exist in a function that calls
the COMMENT SQL command.
Previously this combination caused a parse error.
Add new optional warning and error checks to PL/pgSQL (Pavel Stehule) §
The new checks allow for run-time validation of
INTO column counts and single-row results.
Add connection parameter tcp_user_timeout to control libpq's TCP timeout (Ryohei Nagaura) §
Allow libpq (and thus
psql) to report only the
SQLSTATE value in error messages (Didier Gautheron)
§
Add libpq
function PQresultMemorySize()
to report the memory used by a query result (Lars Kanis, Tom Lane)
§
Remove the no-display/debug flag from libpq's
options connection parameter (Peter Eisentraut)
§
This allows this parameter to be set by postgres_fdw.
Allow ecpg to create variables of data type
bytea (Ryo Matsumura)
§
This allows ECPG clients to interact with bytea data
directly, rather than using an encoded form.
Add PREPARE AS support to
ECPG (Ryo Matsumura)
§
Allow vacuumdb to select tables for vacuum based on their wraparound horizon (Nathan Bossart) §
The options are --min-xid-age and
--min-mxid-age.
Allow vacuumdb to disable waiting for locks or skipping all-visible pages (Nathan Bossart) §
The options are --skip-locked and
--disable-page-skipping.
Add colorization to the output of command-line utilities (Peter Eisentraut) §
This is enabled by setting the environment variable
PG_COLOR to always
or auto. The specific colors used can be
adjusted by setting the environment variable
PG_COLORS, using ANSI escape codes for colors.
For example, the default behavior is equivalent to
PG_COLORS="error=01;31:warning=01;35:locus=01".
Add CSV table output mode in psql (Daniel Vérité) §
This is controlled by \pset format csv or the
command-line --csv option.
Show the manual page URL in
psql's \help output
for a SQL command (Peter Eisentraut)
§
Display the IP address in
psql's \conninfo
(Fabien Coelho)
§
§
Improve tab completion of CREATE TABLE,
CREATE TRIGGER,
CREATE EVENT TRIGGER,
ANALYZE, EXPLAIN,
VACUUM, ALTER TABLE,
ALTER INDEX, ALTER DATABASE,
and ALTER INDEX ALTER COLUMN
(Dagfinn Ilmari Mannsåker, Tatsuro Yamada, Michaël Paquier,
Tom Lane, Justin Pryzby)
§
§
§
§
§
§
§
§
§
Allow control of log file rotation via pg_ctl (Kyotaro Horiguchi, Alexander Kuzmenkov, Alexander Korotkov) §
Previously, this was only possible via an SQL function or a process signal.
Properly detach the new server process
during pg_ctl start
(Paul Guo)
§
This prevents the server from being shut down if the shell script that invoked pg_ctl is interrupted later.
Allow pg_upgrade to use the file system's cloning feature, if there is one (Peter Eisentraut) §
The --clone option has the advantages of
--link, while preventing the old cluster from
being changed after the new cluster has started.
Allow specification of the socket directory to use in pg_upgrade (Daniel Gustafsson) §
This is controlled by --socketdir; the default
is the current directory.
Allow pg_checksums to disable fsync operations (Michaël Paquier) §
This is controlled by the --no-sync option.
Allow pg_rewind to disable fsync operations (Michaël Paquier) §
Fix pg_test_fsync to report accurate
open_datasync durations on
Windows (Laurenz Albe)
§
§
When pg_dump emits data
with INSERT commands rather
than COPY, allow more than one data row to be
included in each INSERT (Surafel Temesgen,
David Rowley)
§
§
The option controlling this is --rows-per-insert.
Allow pg_dump to emit INSERT
... ON CONFLICT DO NOTHING (Surafel Temesgen)
§
This avoids conflict failures during restore.
The option is --on-conflict-do-nothing.
Decouple the order of operations in a parallel pg_dump from the order used by a subsequent parallel pg_restore (Tom Lane) §
This allows pg_restore to perform more-fully-parallelized parallel restores, especially in cases where the original dump was not done in parallel. Scheduling of a parallel pg_dump is also somewhat improved.
Allow the extra_float_digits setting to be specified for pg_dump and pg_dumpall (Andrew Dunstan) §
This is primarily useful for making dumps that are exactly comparable across different source server versions. It is not recommended for normal use, as it may result in loss of precision when the dump is restored.
Add --exclude-database option to
pg_dumpall (Andrew Dunstan)
§
Add CREATE ACCESS METHOD command to create new table types (Andres Freund, Haribabu Kommi, Álvaro Herrera, Alexander Korotkov, Dmitry Dolgov) § § § § § § § § §
This enables the development of new table
access methods, which can optimize storage for different
use cases. The existing heap access method
remains the default.
Add planner support function interfaces to improve optimizer estimates, inlining, and indexing for functions (Tom Lane) § § §
This allows extensions to create planner support functions that can provide function-specific selectivity, cost, and row-count estimates that can depend on the function's arguments. Support functions can also supply simplified representations and index conditions, greatly expanding optimization possibilities.
Simplify renumbering manually-assigned OIDs, and establish a new project policy for management of such OIDs (John Naylor, Tom Lane) § §
Patches that manually assign OIDs for new built-in objects (such as
new functions) should now randomly choose OIDs in the range
8000—9999. At the end of a development cycle, the OIDs used
by committed patches will be renumbered down to lower numbers,
currently somewhere in the 4xxx range,
using the new renumber_oids.pl
script. This approach should greatly reduce the odds of OID
collisions between different in-process patches.
While there is no specific policy reserving any OIDs for external
use, it is recommended that forks and other projects needing
private manually-assigned OIDs use numbers in the high
7xxx range. This will avoid conflicts
with recently-merged patches, and it should be a long time before
the core project reaches that range.
Build Cygwin binaries using dynamic instead of static libraries (Marco Atzeri) §
Remove configure switch
--disable-strong-random (Michaël Paquier)
§
A strong random-number source is now required.
printf-family functions, as well
as strerror
and strerror_r, now behave uniformly across
platforms within Postgres code (Tom Lane)
§
§
§
§
Notably, printf
understands %m everywhere; on
Windows, strerror copes with Winsock error
codes (it used to do so in backend but not frontend code);
and strerror_r always follows the GNU return
convention.
Require a C99-compliant compiler, and MSVC 2013 or later on Windows (Andres Freund) §
Use pandoc, not lynx, for generating plain-text documentation output files (Peter Eisentraut) § §
This affects only the INSTALL file generated
during make dist and the seldom-used
plain-text postgres.txt output file.
Pandoc produces better output than lynx and avoids some
locale/encoding issues. Pandoc version 1.13 or later is required.
Support use of images in the PostgreSQL documentation (Jürgen Purtz) §
Allow ORDER BY sorts
and LIMIT clauses to be pushed
to postgres_fdw foreign servers in more
cases (Etsuro Fujita)
§
§
Improve optimizer cost accounting for postgres_fdw queries (Etsuro Fujita) § § §
Properly honor WITH CHECK OPTION on views
that reference postgres_fdw tables
(Etsuro Fujita)
§
While CHECK OPTIONs on
postgres_fdw tables are ignored (because
the reference is foreign), views on such tables are considered
local, so this change enforces CHECK OPTIONs
on them. Previously, only INSERTs and
UPDATEs with RETURNING
clauses that returned CHECK OPTION values
were validated.
Allow pg_stat_statements_reset()
to be more granular (Haribabu Kommi, Amit Kapila)
§
The function now allows reset of statistics for specific databases, users, and queries.
Allow control of the auto_explain log level (Tom Dunstan, Andrew Dunstan) §
The default is LOG.
Update unaccent rules with new punctuation and symbols (Hugh Ranalli, Michaël Paquier) §
Allow unaccent to handle some accents encoded as combining characters (Hugh Ranalli) §
Allow unaccent to remove accents from Greek characters (Tasos Maschalidis) §
Add a parameter to
amcheck's bt_index_parent_check()
function to check each index tuple from the root of the tree
(Peter Geoghegan)
§
Improve oid2name and vacuumlo option handling to match other commands (Tatsuro Yamada) § §
The following individuals (in alphabetical order) have contributed to this release as patch authors, committers, reviewers, testers, or reporters of issues.
| Abhijit Menon-Sen |
| Achilleas Mantzios |
| Adam Berlin |
| Adam Bielanski |
| Aditya Toshniwal |
| Adrien Nayrat |
| Alan Jackson |
| Albert Schabhuetl |
| Aleksander Alekseev |
| Alex Aktsipetrov |
| Alex Kliukin |
| Alex Macy |
| Alexander Korotkov |
| Alexander Kukushkin |
| Alexander Kuzmenkov |
| Alexander Lakhin |
| Alexandra Ryzhevich |
| Alexey Bashtanov |
| Alexey Ermakov |
| Alexey Kondratov |
| Alexey Kryuchkov |
| Alexey Stepanov |
| Allison Kaptur |
| Álvaro Herrera |
| Alyssa Ross |
| Amit Kapila |
| Amit Khandekar |
| Amit Langote |
| Amul Sul |
| Anastasia Lubennikova |
| André Hänsel |
| Andrea Gelmini |
| Andreas Joseph Krogh |
| Andreas Karlsson |
| Andreas Kunert |
| Andreas Scherbaum |
| Andreas Seltenreich |
| Andrei Yahorau |
| Andres Freund |
| Andrew Dunstan |
| Andrew Fletcher |
| Andrew Gierth |
| Andrew Krasichkov |
| Andrey Borodin |
| Andrey Klychkov |
| Andrey Lepikhov |
| Andy Abelisto |
| Anthony Greene |
| Anthony Skorski |
| Antonin Houska |
| Arne Roland |
| Arseny Sher |
| Arthur Zakirov |
| Ash Marath |
| Ashutosh Bapat |
| Ashutosh Sharma |
| Ashwin Agrawal |
| Aya Iwata |
| Bartosz Polnik |
| Basil Bourque |
| Bernd Helmle |
| Brad DeJong |
| Brigitte Blanc-Lafay |
| Bruce Klein |
| Bruce Momjian |
| Bruno Wolff |
| Chapman Flack |
| Chen Huajun |
| Chris Travers |
| Chris Wilson |
| Christian Hofstaedtler |
| Christoph Berg |
| Christoph Moench-Tegeder |
| Clemens Ladisch |
| Colm McHugh |
| Corey Huinker |
| Craig Ringer |
| Dagfinn Ilmari Mannsåker |
| Daisuke Higuchi |
| Daniel Fiori |
| Daniel Gustafsson |
| Daniel Vérité |
| Daniel Westermann |
| Daniel Wilches |
| Darafei Praliaskouski |
| Daryl Waycott |
| Dave Cramer |
| David Binderman |
| David Fetter |
| David G. Johnston |
| David Rowley |
| David Steele |
| Davy Machado |
| Dean Rasheed |
| Derek Hans |
| Derek Nelson |
| Devrim Gündüz |
| Dian Fay |
| Didier Gautheron |
| Dilip Kumar |
| Dmitry Dolgov |
| Dmitry Marakasov |
| Dmitry Molotkov |
| Dmitry Shalashov |
| Don Seiler |
| Donald Dong |
| Doug Rady |
| Edmund Horner |
| Eduards Bezverhijs |
| Elvis Pranskevichus |
| Emanuel Araújo |
| Emre Hasegeli |
| Eric Cyr |
| Erik Rijkers |
| Ertugrul Kahveci |
| Etsuro Fujita |
| Eugen Konkov |
| Euler Taveira |
| Fabien Coelho |
| Fabrízio de Royes Mello |
| Feike Steenbergen |
| Filip Rembialkowski |
| Gaby Schilders |
| Geert Lobbestael |
| George Tarasov |
| Georgios Kokolatos |
| Gianni Ciolli |
| Gilles Darold |
| Greg Stark |
| Grigory Smolkin |
| Guillaume Lelarge |
| Gunnlaugur Thor Briem |
| Gurjeet Singh |
| Hadi Moshayedi |
| Hailong Li |
| Hans Buschmann |
| Haribabu Kommi |
| Haruka Takatsuka |
| Hayato Kuroda |
| Heikki Linnakangas |
| Hironobu Suzuki |
| Hubert Lubaczewski |
| Hugh Ranalli |
| Ian Barwick |
| Ibrar Ahmed |
| Ildar Musin |
| Insung Moon |
| Ioseph Kim |
| Isaac Morland |
| Ivan Panchenko |
| Jack Kelly |
| Jacob Champion |
| Jaime Casanova |
| Jakob Egger |
| Jakub Glapa |
| Jakub Janecek |
| James Coleman |
| James Inform |
| James Robinson |
| James Sewell |
| James Tomson |
| Jan Chochol |
| Jaroslav Sivy |
| Jean-Christophe Arnu |
| Jean-Marc Voillequin |
| Jean-Pierre Pelletier |
| Jeevan Chalke |
| Jeevan Ladhe |
| Jeff Davis |
| Jeff Janes |
| Jeremy Evans |
| Jeremy Schneider |
| Jeremy Smith |
| Jerry Jelinek |
| Jesper Pedersen |
| Jianing Yang |
| Jie Zhang |
| Jim Nasby |
| Jimmy Yih |
| Joe Conway |
| Joe Wildish |
| Joerg Sonnenberger |
| John Klann |
| John Naylor |
| Jonah Harris |
| Jonathan S. Katz |
| Jorge Gustavo Rocha |
| José Arthur Benetasso Villanova |
| Joshua D. Drake |
| Juan José Santamaría Flecha |
| Julian Hsiao |
| Julian Markwort |
| Julian Schauder |
| Julien Rouhaud |
| Jürgen Purtz |
| Jürgen Strobel |
| Justin Pryzby |
| Kaiting Chen |
| Karen Huddleston |
| Karl Czajkowski |
| Karl O. Pinc |
| Keiichi Hirobe |
| Keith Fiske |
| Ken Tanzer |
| Kenji Uno |
| Kevin Grittner |
| Kevin Hale Boyes |
| Kieran McCusker |
| Kirk Jamison |
| Kohei KaiGai |
| Konstantin Knizhnik |
| Konstantin Kuznetsov |
| Kristjan Tammekivi |
| Kuntal Ghosh |
| Kyle Samson |
| Kyotaro Horiguchi |
| Lætitia Avrot |
| Lars Kanis |
| Laurenz Albe |
| Lim Myungkyu |
| Liu Huailing |
| Liudmila Mantrova |
| Lloyd Albin |
| Luca Ferrari |
| Luis M. Carril |
| Lukas Eder |
| Lukas Fittl |
| Madelaine Thibaut |
| Madeleine Thompson |
| Magnus Hagander |
| Mahendra Singh |
| Mai Peng |
| Maksim Milyutin |
| Maksym Boguk |
| Malthe Borch |
| Manuel Rigger |
| Marco Atzeri |
| Marco Slot |
| Marina Polyakova |
| Mario De Frutos Dieguez |
| Marius Timmer |
| Mark Chambers |
| Mark Dilger |
| Marko Tiikkaja |
| Markus Winand |
| Martín Marqués |
| Masahiko Sawada |
| Masao Fujii |
| Mateusz Guzik |
| Mathias Brossard |
| Matt Williams |
| Matthias Otterbach |
| Matvey Arye |
| Melanie Plageman |
| Mi Tar |
| Michael Banck |
| Michael Davidson |
| Michael Meskes |
| Michael Paquier |
| Michael Vitale |
| Michel Pelletier |
| Mikalai Keida |
| Mike Palmiotto |
| Mithun Cy |
| Morgan Owens |
| Murat Kabilov |
| Nathan Bossart |
| Nawaz Ahmed |
| Neeraj Kumar |
| Nick Barnes |
| Nico Williams |
| Nikita Glukhov |
| Nikolay Shaplov |
| Ning Yu |
| Nishant Fnu |
| Noah Misch |
| Norbert Benkocs |
| Noriyoshi Shinoda |
| Oleg Bartunov |
| Oleg Samoilov |
| Oleksii Kliukin |
| Ondrej Bouda |
| Oskari Saarenmaa |
| Pan Bian |
| Patrick Francelle |
| Patrick McHardy |
| Paul A. Jungwirth |
| Paul Bonaud |
| Paul Guo |
| Paul Martinez |
| Paul Ramsey |
| Paul Schaap |
| Paul van der Linden |
| Pavan Deolasee |
| Pavel Oskin |
| Pavel Raiskup |
| Pavel Stehule |
| Peifeng Qiu |
| Peter Billen |
| Peter Eisentraut |
| Peter Geoghegan |
| Peter Neave |
| Petr Fedorov |
| Petr Jelínek |
| Petr Slavov |
| Petru-Florin Mihancea |
| Phil Bayer |
| Phil Florent |
| Philip Dubé |
| Pierre Ducroquet |
| Piotr Gabriel Kosinski |
| Piotr Stefaniak |
| Piotr Wlodarczyk |
| Prabhat Sahu |
| Quentin Rameau |
| Rafael Castro |
| Rafia Sabih |
| Rahila Syed |
| Rajkumar Raghuwanshi |
| Rares Salcudean |
| Raúl Marín Rodríguez |
| Regina Obe |
| Renaud Navarro |
| Richard Guo |
| Rick Otten |
| Rikard Falkeborn |
| RK Korlapati |
| Robbie Harwood |
| Robert Haas |
| Robert Treat |
| Robert Vollmert |
| Roger Curley |
| Roman Zharkov |
| Ronan Dunklau |
| Rui Hai Jiang |
| Rushabh Lathia |
| Ryan Lambert |
| Ryo Matsumura |
| Ryohei Nagaura |
| Ryohei Takahashi |
| Samuel Williams |
| Sand Stone |
| Sanyo Capobiango |
| Satoru Koizumi |
| Sean Johnston |
| Serge Latyntsev |
| Sergei Kornilov |
| Sergey Pashkov |
| Sergio Conde Gómez |
| Shawn Debnath |
| Shay Rojansky |
| Sho Kato |
| Shohei Mochizuki |
| Shouyu Luo |
| Simon Riggs |
| Sivasubramanian Ramasubramanian |
| Slawomir Chodnicki |
| Stas Kelvish |
| Stefan Kadow |
| Stepan Yankevych |
| Stephen Amell |
| Stephen Frost |
| Steve Rogerson |
| Steve Singer |
| Steven Winfield |
| Surafel Temesgen |
| Suraj Kharage |
| Suresh Kumar R |
| Takayuki Tsunakawa |
| Takeshi Ideriha |
| Takuma Hoshiai |
| Tasos Maschalidis |
| Tatsuo Ishii |
| Tatsuro Yamada |
| Teodor Sigaev |
| Thom Brown |
| Thomas Munro |
| Thomas Poty |
| Tillmann Schulz |
| Tim Möhlmann |
| Timur Birsh |
| Tobias Bussmann |
| Tom Cassidy |
| Tom Dunstan |
| Tom Gottfried |
| Tom Lane |
| Tomas Vondra |
| Tushar Ahuja |
| Ulf Adams |
| Vaishnavi Prabakaran |
| Victor Petrovykh |
| Victor Wagner |
| Victor Yegorov |
| Vijaykumar Jain |
| Vik Fearing |
| Vlad Sterzhanov |
| Vladimir Baranoff |
| Vladimir Kriukov |
| Wu Fei |
| Yaroslav Schekin |
| Yi Huang |
| Yoshikazu Imai |
| Yugo Nagata |
| Yulian Khodorkovskiy |
| Yuming Wang |
| YunQiang Su |
| Yuri Kurenkov |
| Yusuke Egashira |
| Yuzuko Hosoya |
| Zhou Digoal |