+ linkend="pg-stat-activity-view">pg_stat_activity
+ view's information about what a process is waiting for (Amit Kapila,
+ Ildus Kurbangaliev)
+
+
+ Historically a process has only been shown as waiting if it was
+ waiting for a heavyweight lock. Now waits for lightweight locks
+ and buffer pins are also shown in pg_stat_activity.
+ Also, the type of lock being waited for is now visible.
+
+
+
+
+
+ Add pg_stat_progress_vacuum
+ system view to provide progress reporting for VACUUM
+ operations (Amit Langote, Robert Haas, Vinayak Pokale, Rahila Syed)
+
+
+
+
+
+ Add pg_config
+ system view to expose the same information available from
+ the
pg_config utility (Joe Conway)+
+
+
+
+
+ Add a confirmed_flush_lsn column to
+ the pg_replication_slots
+ system view (Marko Tiikkaja)
+
+
+
+
+
+ Add pg_stat_wal_receiver
+ system view to provide information about the state of a hot-standby
+ server's WAL receiver process (Michael Paquier)
+
+
+
+
+
+ Add pg_blocking_pids() function to reliably identify
+ which sessions block which others (Tom Lane)
+
+
+ This function returns an array of the process IDs of any sessions that
+ are blocking the session with the given process ID. Historically
+ users have obtained such information using a self-join on
+ the pg_locks view; but it's unreasonably tedious to do
+ it that way with any modicum of correctness, and the addition of
+ parallel queries has made the approach entirely impractical, since
+ locks might be held or awaited by child worker processes rather than
+ the session's main process.
+
+
+
+
+
+ Add pg_control_system(),
+ pg_control_checkpoint(),
+ pg_control_recovery(),
+ and pg_control_init() functions to expose fields
+ of pg_control to SQL (Joe Conway, Michael Paquier)
+
+
+
+
+
+ Add function pg_current_xlog_flush_location() to expose
+ the current transaction log flush location (Tomas Vondra)
+
+
+
+
+
+ Add function pg_notification_queue_usage() to report
+ how full the NOTIFY queue is (Brendan Jurd)
+
+
+
+
+
+ Limit the verbosity of memory context statistics dumps (Tom Lane)
+
+
+ The memory usage dump printed to the postmaster log during an
+ out-of-memory failure now summarizes statistics when there are a large
+ number of memory contexts, rather than possibly printing a very large
+ report. There's also a grand total summary line now.
+
+
+
+
+
+ Change display format for NextXID in
pg_controldata+ and related places (Joe Conway, Bruce Momjian)
+
+
+ Display epoch-and-transaction-ID values in the
+ format number:number.
+ The previous
+ format number/number was
+ confusingly similar to that used for LSNs.
+
+
+
+
+
+
+
+
+
<acronym>Authentication</>
+
+
+
+
+
+ Create a bsd authentication method to allow use of
+ the BSD Authentication service for
PostgreSQL+ client authentication (Marisa Emerson)
+
+
+ BSD Authentication is currently only available on OpenBSD.
+
+
+
+
+
+ When using PAM authentication, provide the client IP address or host
+ name to PAM modules via the PAM_RHOST item (Grzegorz
+ Sampolski)
+
+
+
+
+
+ Provide detail in the postmaster log for more password authentication
+ failures (Tom Lane)
+
+
+ All ordinarily-reachable password authentication failure cases should
+ now provide specific DETAIL fields in the log.
+
+
+
+
+
+ Support RADIUS passwords up to 128 characters long (Marko Tiikkaja)
+
+
+
+
+
+ Add new SSPI authentication parameters compat_realm
+ and upn_usename, to make it possible to make SSPI
+ work more like GSSAPI (Christian Ullrich)
+
+
+
+
+
+
+
+
+
Server Configuration
+
+
+
+
+
+ Add
+ sd_notify() at server start and stop
+ (Peter Eisentraut)
+
+
+ This allows the use of
systemd service units of+ type notify, which greatly simplifies management
+ of
PostgreSQL under systemd.+
+
+
+
+
+ Allow effective_io_concurrency to be set as a
+ tablespace parameter, to support cases where different tablespaces
+ have different I/O characteristics (Julien Rouhaud)
+
+
+
+
+
+ Allow sessions to be terminated automatically if they sit too long in
+ an idle-in-transaction state (Vik Fearing)
+
+
+ This behavior is enabled and controlled by the new configuration
+ parameter .
+ It can be useful to prevent forgotten transactions from holding onto
+ locks or preventing vacuum cleanup for very long periods.
+
+
+
+
+
+ Add log_line_prefix option %n to print the
+ time as a Unix epoch, with milliseconds (Tomas Vondra, Jeff Davis)
+
+
+
+
+
+ Add
+ and
+ configuration parameters to provide more control over message format
+ when logging to syslog (Peter Eisentraut)
+
+
+
+
+
+ Merge the archive and hot_standby values of
+ the configuration parameter into a
+ single value replica (Peter Eisentraut)
+
+
+ Making a distinction between these settings no longer appears to be a
+ good idea, and it's in the way of planned future simplification of
+ replication setup. The old names are still accepted but are
+ converted internally.
+
+
+
+
+
+ Allow the server's SSL key file to have group read access if owned by
+ root (Christoph Berg)
+
+
+ Formerly we insisted on the key file being owned by the user running
+ the
PostgreSQL server, but that is inconvenient for+ some systems (such as Debian) that wish to manage certificates
+ centrally. So also allow the case where the key file is owned by
+ root and has group read access. It's up to the root admin to ensure
+ that such a group doesn't include any untrusted users.
+
+
+
+
+
+
+
+
+
Reliability
+
+
+
+
+
+ Force backends to exit if the postmaster dies
+ (Rajeev Rastogi and Robert Haas)
+
+
+ Under normal circumstances the postmaster should always outlive its
+ child processes. If for some reason it dies, cause backend sessions
+ to exit with an error. Formerly, existing backends would continue to
+ run until their client disconnects; but that is unsafe and
+ inefficient, and furthermore it prevents a new postmaster from being
+ started until the last old backend is gone. Backends will detect
+ postmaster death when waiting for client I/O, so the exit will not be
+ instantaneous, but in most circumstances it should happen no later
+ than the end of the current query.
+
+
+
+
+
+ Check for serializability conflicts before reporting
+ constraint-violation failures (Thomas Munro)
+
+
+ When using serializable transaction isolation, it is desirable that
+ any error due to a concurrent transaction should manifest as a
+ serialization failure, thereby cueing the application that a retry
+ might succeed. Unfortunately, this doesn't reliably happen for
+ duplicate-key failures caused by concurrent insertions. This change
+ ensures that such an error will be reported as a serialization error,
+ if the application explicitly checked for the presence of a
+ conflicting key (and didn't find it) earlier in the transaction.
+
+
+
+
+
+ Ensure that invalidation messages are recorded in WAL even when
+ issued by a transaction that has no XID assigned (Andres Freund)
+
+
+ This fixes some corner cases in which transactions on standby
+ servers failed to notice changes such as new indexes.
+
+
+
+
+
+ Prevent multiple processes from trying to clean a GIN index's pending
+ list concurrently (Teodor Sigaev, Jeff Janes)
+
+
+ This had been intentionally allowed, but it causes race conditions
+ that can result in vacuum missing index entries it needs to delete.
+
+
+
+
+
+ Clear the OpenSSL error queue before OpenSSL calls, rather than
+ assuming it's clear already; and make sure we leave it clear
+ (Peter Geoghegan, Dave Vitek, Peter Eisentraut)
+
+
+ This avoids problems when there are multiple connections using
+ OpenSSL within a single process and not all the code involved
+ follows the same rules for when to clear the error queue.
+ While the problem is worse for
libpq, it's+ possible for it to arise within the server as well.
+
+
+
+
+
+
+
+
+
+
+
Replication and Recovery
+
+
+
+
+
+ Add a feature to the replication protocol, and a corresponding option
+ to the pg_create_physical_replication_slot() function,
+ to allow reserving WAL immediately when creating a replication slot
+ (Gurjeet Singh, Michael Paquier)
+
+
+ This allows creation of a replication slot to guarantee that all the
+ WAL for a base backup will be available afterwards.
+
+
+
+
+
+ Add a
option to
pg_basebackup+ (Peter Eisentraut)
+
+
+ This lets
pg_basebackup use a replication slot defined+ for WAL streaming. After the base backup completes, selecting the
+ same slot for regular streaming replication allows seamless startup of
+ the new standby server.
+
+
+
+
+
+ Extend pg_start_backup() and pg_stop_backup()
+ to support non-exclusive backups (Magnus Hagander)
+
+
+
+
+
+ Support synchronous replication with multiple synchronous standby
+ servers, not just one (Sawada Masahiko, Beena Emerson, Michael
+ Paquier, Fujii Masao, Kyotaro Horiguchi)
+
+
+
+
+
+ Add new setting remote_apply for configuration parameter
+ (Thomas Munro)
+
+
+ In this mode, the master waits for the transaction to be applied on
+ the standby server, not just written to disk. That means that you
+ can count on a transaction started on the standby to see all commits
+ previously acknowledged by the master.
+
+
+
+
+
+
+
+
+
Queries
+
+
+
+
+
+ Widen tuples-processed counters to 64 bits (Andreas Scherbaum)
+
+
+ This change allows command tags for SELECT etc. to
+ correctly report tuple counts larger than 4 billion. So will
+ PL/pgSQL's GET DIAGNOSTICS ... ROW_COUNT command.
+
+
+
+
+
+ Avoid doing encoding conversions by double-conversion
+ through MULE_INTERNAL encoding (Tom Lane)
+
+
+ Previously, many conversions for Cyrillic and Central European
+ single-byte encodings were done by converting to a
+ related MULE_INTERNAL coding scheme and then to the
+ destination encoding. Aside from being inefficient, this meant that
+ when the conversion encountered an untranslatable character, the error
+ message would confusingly complain about failure to convert to or
+ from MULE_INTERNAL, rather than the user-visible
+ encodings.
+
+
+
+
+
+ Push down joins of foreign tables to the foreign data wrapper only
+ when the user mappings match (Shigeru Hanada, Ashutosh Bapat)
+
+
+ Previously, the foreign join pushdown infrastructure left the question
+ of security entirely up to individual foreign data wrappers, but it
+ would be easy for an FDW to inadvertently open up subtle security
+ holes that way. So, make it the core code's job to determine which
+ user mapping OID is relevant, and don't attempt join pushdown unless
+ it's the same for all relevant relations.
+
+
+
+
+
+
+
+
+
Utility Commands
+
+
+
+
+
+ Allow COPY to copy the output of
+ an INSERT/UPDATE/DELETE
+ ... RETURNING query (Marko Tiikkaja)
+
+
+ Previously, an intermediate CTE had to be written to get this result.
+
+
+
+
+
+ Introduce ALTER object DEPENDS ON
+ EXTENSION (Abhijit Menon-Sen)
+
+
+ This command allows a database object to be marked as depending on an
+ extension, so that it will automatically go away if the extension is
+ dropped (without needing CASCADE). But the object is not
+ part of the extension, and thus for example will be dumped separately
+
+
+
+
+
+ Make ALTER object SET SCHEMA do nothing
+ when the object is already in the requested schema, rather than
+ throwing an error as it historically has for most object types (Marti
+ Raudsepp)
+
+
+
+
+
+ Add options to ALTER OPERATOR to change the
+ selectivity functions associated with an existing operator
+ (Uriy Zhuravlev)
+
+
+
+
+
+ Add an
+ COLUMN (Fabrízio de Royes Mello)
+
+
+
+
+
+ Reduce the lock strength needed by ALTER TABLE when
+ setting fillfactor and autovacuum-related relation options
+ (Fabrízio de Royes Mello, Simon Riggs)
+
+
+
+
+
+ Introduce CREATE ACCESS METHOD to allow extensions to
+ create index access methods (Alexander Korotkov, Petr Jelínek)
+
+
+
+
+
+ Add a CASCADE option to CREATE
+ EXTENSION, to automatically create extensions it depends on
+ (Petr Jelínek)
+
+
+
+
+
+ Remove the
+ long-deprecated CREATEUSER/NOCREATEUSER
+ options from CREATE ROLE and allied commands (Tom Lane)
+
+
+ CREATEUSER actually meant SUPERUSER, for
+ ancient backwards-compatibility reasons. That's been a constant
+ source of confusion for people who (reasonably) expect it to
+ mean CREATEROLE. It's been deprecated for ten years
+ now, so fix the problem by removing it.
+
+
+
+
+
+ Make CREATE TABLE ... LIKE include an OID column if any
+ source table has one (Bruce Momjian)
+
+
+
+
+
+ If a CHECK constraint is declared NOT VALID in
+ a table creation command, automatically mark it valid (Amit Langote,
+ Amul Sul)
+
+
+ This matches the longstanding behavior of FOREIGN KEY
+ constraints.
+
+
+
+
+
+ Fix DROP OPERATOR to
+ clear pg_operator.oprcom
+ and pg_operator.oprnegate links to the
+ dropped operator (Roma Sokolov)
+
+
+ Formerly such links were left as-is, which could pose a problem in
+ the somewhat unlikely event that the dropped operator's OID was
+ reused for another operator.
+
+
+
+
+
+ Disallow creation of indexes on system columns, except for OID
+ (David Rowley)
+
+
+ Such indexes were never considered supported, and would very possibly
+ misbehave since the system might change the system-column fields of a
+ tuple without updating indexes. But there was no error check to
+ prevent them from being created.
+
+
+
+
+
+
+
+
+
Permissions Management
+
+
+
+
+
+ Use the privilege system to manage access to sensitive functions
+ (Stephen Frost)
+
+
+ Formerly, many security-sensitive functions contained hard-wired
+ checks that would throw an error if they were called by a
+ non-superuser role. This forced use of superuser roles for some
+ relatively pedestrian tasks. The hard-wired error checks are now gone
+ in favor of making
initdb revoke the default+ public EXECUTE privilege on these functions. This allows
+ installations to choose to grant usage of such functions to trusted
+ roles that need not have full superuser privilege.
+
+
+
+
+
+ Treat role names beginning with pg_ as reserved
+ (Stephen Frost)
+
+
+ User creation of such role names is now disallowed. This prevents
+ conflicts with built-in roles created by
initdb.+
+
+
+
+
+ Create some built-in roles that
+ can be used to grant access to what were previously superuser-only
+ functions (Stephen Frost)
+
+
+
+
+
+
+
+
+
Data Types
+
+
+
+
+
+ Allow omitting one or both boundaries in an array slice specifier,
+ for example array_col[3:]
+ (YUriy Zhuravlev)
+
+
+ Omitted boundaries are taken as the upper or lower limit of the
+ corresponding array subscript. This allows simpler specification of
+ many common use-cases.
+
+
+
+
+
+ Be more careful about out-of-range dates and timestamps
+ (Vitaly Burovoy)
+
+
+ This change prevents unexpected out-of-range errors
+ for timestamp with time zone values very close to the
+ implementation limits. Previously, the same value might be
+ accepted or not depending on the timezone setting,
+ meaning that a dump and reload could fail on a value that had been
+ accepted when presented. Now the limits are enforced according to
+ the equivalent UTC time, not local time, so as to be independent
+ of timezone.
+
+
+ Also,
PostgreSQL is now more careful to detect+ overflow in operations that compute new date or timestamp values,
+ such as date + integer.
+
+
+
+
+
+ In the geometric data types, make sure that infinity and NaN
+ component values are treated consistently during input and output
+ (Tom Lane)
+
+
+ Such values will now always print the same way as they would in a
+ simple float8 column, and be accepted the same way on input
+ as well. Previously the behavior was somewhat platform-dependent.
+
+
+
+
+
+ Improve full text search to support searching for phrases, that is,
+ lexemes appearing adjacent to each other in a specific order, or with
+ at most a specified distance between them
+ (Teodor Sigaev, Oleg Bartunov, Dmitry Ivanov)
+
+
+ A phrase-search query can be specified in tsquery input
+ using the new operators <-> and
+ <N>. The former means that
+ the lexemes before and after it must appear adjacent to each other in
+ that order. The latter means they can be separated by up
+ to N other lexemes.
+
+
+
+
+
+ Fix text search parser to allow leading digits in email
+ and host tokens (Artur Zakirov)
+
+
+ In most cases this will result in few changes in the parsing of text.
+ But if you have data where such addresses occur frequently, it may be
+ worth rebuilding dependent tsvector columns and indexes, so
+ that addresses of this form will be found properly by text searches.
+
+
+
+
+
+ Upgrade the ispell dictionary to handle modern Hunspell
+ files and support more languages (Artur Zakirov)
+
+
+
+
+
+ Implement lookbehind constraints in regular expressions
+ (Tom Lane)
+
+
+ A lookbehind constraint is like a lookahead constraint in that it
+ consumes no text; but it checks for existence (or nonexistence) of a
+ match ending at the current point in the string, rather than one
+ starting at the current point. Similar features exist in many other
+ regular-expression engines.
+
+
+
+
+
+ In regular expressions, if an apparent three-digit octal
+ escape \nnn would exceed 377 (255
+ decimal), assume it is a two-digit octal escape instead (Tom Lane)
+
+
+ This makes the behavior match current Tcl releases.
+
+
+
+
+
+ Add xid <> xid
+ and xid <> int4 operators,
+ for consistency with the corresponding = operators
+ (Michael Paquier)
+
+
+
+
+
+
+
+
+
Functions
+
+
+
+
+
+ Add jsonb_insert() function to insert a new element into
+ a jsonb array, or a not-previously-existing key into
+ a jsonb object (Dmitry Dolgov)
+
+
+
+
+
+ Improve the accuracy of the ln(), log(),
+ exp(), and pow() functions for type
+ numeric (Dean Rasheed)
+
+
+
+
+
+ Add a scale(numeric) function to extract the display
+ scale of a numeric value (Marko Tiikkaja)
+
+
+
+
+
+ Add trigonometric functions that work in degrees (Dean Rasheed)
+
+
+ For example, sind() measures its argument in
+ degrees, whereas sin() measures in radians.
+ These functions go to some lengths to deliver exact results for values
+ where an exact result can be expected, such
+ as sind(30) = 0.5 exactly.
+
+
+
+
+
+ Ensure that trigonometric functions handle infinity and NaN inputs per
+ spec (Dean Rasheed)
+
+
+ The POSIX standard says that these functions should return NaN for NaN
+ input, and should throw an error for out-of-range inputs including
+ infinity; but previously, our actual behavior varied across platforms.
+
+
+
+
+
+ Make extract() behave more reasonably with infinite
+ inputs (Vitaly Burovoy)
+
+
+ Historically the extract() function just returned zero
+ given an infinite timestamp, regardless of the given unit name. Make
+ it return infinity or -infinity
+ as appropriate when the requested field is one that is monotonically
+ increasing (e.g, year, epoch), or NULL when it is not (e.g., day,
+ hour). Also, throw the expected error for bad unit names.
+
+
+
+
+
+ Make to_timestamp(float8) convert float infinity to
+ timestamp infinity (Vitaly Burovoy)
+
+
+ Formerly it just failed on an infinite input.
+
+
+
+
+
+ Add new functions for tsvector data (Stas Kelvich)
+
+
+ These are delete(), filter(),
+ unnest(), tsvector_to_array(),
+ array_to_tsvector(), and a variant
+ of setweight() that sets the weight only for specified
+ lexeme(s).
+
+
+
+
+
+ Allow ts_stat_sql()
+ and tsvector_update_trigger() to operate on values that
+ are of types binary-compatible with the expected argument type, not
+ just that argument type; for example allow citext
+ where text is expected (Teodor Sigaev)
+
+
+
+
+
+ Add variadic functions num_nulls()
+ and num_nonnulls() that count the number of their
+ arguments that are null or nonnull (Marko Tiikkaja)
+
+
+ An example usage is CHECK(num_nonnulls(a,b,c) = 1) which
+ asserts that exactly one of a,b,c isn't NULL. These functions can
+ also be pressed into service to count the number of null or nonnull
+ elements in an array.
+
+
+
+
+
+ Add function parse_ident() to split a qualified,
+ possibly quoted SQL identifier into its parts (Pavel Stehule)
+
+
+
+
+
+ In to_char(), do not count a minus sign (when needed) as
+ part of the field width for time-related fields (Bruce Momjian)
+
+
+ For example, to_char('-4 years'::interval, 'YY') now
+ returns -04, rather than -4.
+
+
+
+
+
+ In to_number(), interpret V as dividing by
+ 10 to the power of the number of digits following V
+ (Bruce Momjian)
+
+
+ This makes it operate in an inverse fashion to to_char().
+
+
+
+
+
+ Make the to_reg*() functions accept type text
+ not cstring (Petr Korobeinikov)
+
+
+ This avoids the need to write an explicit cast in most cases where
+ the argument isn't a simple literal constant.
+
+
+
+
+
+ Add pg_size_bytes() function to convert human-readable
+ size strings to numbers (Pavel Stehule, Vitaly Burovoy)
+
+
+ This function converts strings like those produced
+ by pg_size_pretty() into sizes in bytes. An example
+ usage is WHERE pg_total_relation_size(oid) >
+ pg_size_bytes('10 GB').
+
+
+
+
+
+ In pg_size_pretty(), format negative numbers similarly to
+ positive ones (Adrian Vondendriesch)
+
+
+
+
+
+ Add an optional missing_ok argument to
+ the current_setting() function (David Christensen)
+
+
+
+
+
+
+
+
+
Server-Side Languages
+
+
+
+
+
+ In PL/pgSQL,
+ detect mismatched CONTINUE and EXIT statements
+ while compiling PL/pgSQL functions, rather than at execution
+ (Jim Nasby)
+
+
+
+
+
+ Remove PL/pgSQL's feature that suppressed the innermost line
+ of CONTEXT for messages emitted by RAISE
+ commands (Pavel Stehule)
+
+
+ This ancient backwards-compatibility hack was agreed to have outlived
+ its usefulness.
+
+
+
+
+
+ Extend PL/Python's error-reporting and message-reporting functions to
+ allow specifying additional message fields besides the primary error
+ message (Pavel Stehule)
+
+
+
+
+
+ Allow PL/Python functions to call themselves recursively via SPI,
+ and fix the behavior when multiple set-returning PL/Python functions
+ are called within one query (Alexey Grishchenko, Tom Lane)
+
+
+
+
+
+ Fix session-lifespan memory leaks in PL/Python
+ (Heikki Linnakangas, Haribabu Kommi, Tom Lane)
+
+
+
+
+
+ Modernize
PL/Tcl to use Tcl's object APIs
+ instead of simple strings (Jim Nasby, Karl Lehenbauer)
+
+
+ This can improve performance substantially in some cases.
+ Note that
PL/Tcl now requires Tcl 8.4 or later.+
+
+
+
+
+ In
PL/Tcl, make database-reported errors return+ additional information in Tcl's errorCode global variable
+ (Jim Nasby, Tom Lane)
+
+
+ This feature follows the Tcl convention for returning auxiliary data
+ about an error.
+
+
+
+
+
+ Fix
PL/Tcl to perform encoding conversion between+ the database encoding and UTF-8, which is what Tcl expects (Tom Lane)
+
+
+ Previously, strings were passed through without conversion, leading
+ to misbehavior with non-ASCII characters when the database encoding
+ isn't UTF-8.
+
+
+
+
+
+
+
+
+
Client Interfaces
+
+
+
+
+
+ Introduce a feature in
libpq whereby+ the CONTEXT field of messages can be suppressed, either
+ always or only for non-error messages (Pavel Stehule)
+
+
+ The default behavior of PQerrorMessage() is now to
+ print CONTEXT only for errors. The new
+ function PQsetErrorContextVisibility() can be used to
+ adjust this.
+
+
+
+
+
+ Add support in
libpq for regenerating an error+ message with a different verbosity level (Alex Shulgin)
+
+
+ This supports
psql's new \errverbose+ feature, and may be useful for other clients as well.
+
+
+
+
+
+ Improve
libpq's PQhost() function to+ return useful data for default Unix-socket connections (Tom Lane)
+
+
+ Previously it would return NULL if no explicit host specification had
+ been given; now it returns the default socket directory path.
+
+
+
+
+
+ Fix
ecpg's lexer to handle line breaks within comments+ starting on preprocessor directive lines (Michael Meskes)
+
+
+
+
+
+
+
+
+
Client Applications
+
+
+
+
+
+ Add
+ and
pg_restore (Pavel Stehule)+
+
+ This option causes the program to complain if there is no match for
+ a or option, rather than
+ silently doing nothing.
+
+
+
+
+
+ dump locally-made changes in privilege assignments for system objects
+ (Stephen Frost)
+
+
+ While it's always been possible for a superuser to change the
+ privilege assignments for built-in or extension-created objects,
+ such changes were formerly lost in a dump and reload. Now,
+
pg_dump recognizes and dumps such changes.+ (This works only when dumping from a 9.6 or later server, however.)
+
+
+
+
+
+ In
pg_dump, include the table name in object tags+ for object types that are only uniquely named per-table (for
+ example, triggers) (Peter Eisentraut)
+
+
+
+
+
+ Improve
pg_restore's switch to+ match all types of relations, not only plain tables (Craig Ringer)
+
+
+
+
+
+
+
<xref linkend="APP-PSQL">
+
+
+
+
+
+ Support multiple and
+ command-line options (Pavel Stehule, Catalin Iacob)
+
+
+ To allow this with sane behavior, one backwards incompatibility had to
+ be introduced: no longer
+ implies .
+
+
+
+
+
+ Add a \crosstabview command that prints the
+ results of a query in a cross-tabulated display
+ (Daniel Verité)
+
+
+ In the crosstab display, data values from one query result column are
+ placed in a grid whose column and row headers come from other query
+ result columns.
+
+
+
+
+
+ Add an \errverbose command that shows the last server
+ error at full verbosity (Alex Shulgin)
+
+
+ This is very handy after getting an unexpected error — you no
+ longer need to adjust the VERBOSITY variable and recreate
+ the failure in order to see error fields that aren't shown by
+ default.
+
+
+
+
+
+ Add \ev and \sv commands
+ for editing and showing view definitions (Petr Korobeinikov)
+
+
+ These are parallel to the existing \ef and \sf
+ commands for functions.
+
+
+
+
+
+ Add a \gexec command that executes a query and re-submits
+ the result(s) as new queries (Corey Huinker)
+
+
+
+
+
+ Allow \pset C string to set the
+ table title, for consistency
+ with \C string (Bruce Momjian)
+
+
+
+
+
+ In \pset expanded auto mode, do not use expanded format
+ for query results with only one column (Andreas Karlsson, Robert Haas)
+
+
+
+
+
+ Improve the headers output by the \watch command
+ (Michael Paquier, Tom Lane)
+
+
+ Include the \pset title string if one has been set, and
+ shorten the prefabricated part of the header to be
+ timestamp (every Ns).
+
+
+
+
+
+ Improve tab-completion logic to consider the
+ entire input query, not only the current line (Tom Lane)
+
+
+ Previously, breaking a command into multiple lines defeated any tab
+ completion rules that would have needed to see words on earlier lines.
+
+
+
+
+
+ Numerous minor improvements in tab-completion behavior (Peter
+ Eisentraut, Vik Fearing, Kevin Grittner, Kyotaro Horiguchi, Jeff
+ Janes, Andreas Karlsson, Fujii Masao, Thomas Munro, Masahiko Sawada,
+ Pavel Stehule)
+
+
+
+
+
+ Add a PROMPT option %p to
+ insert the process ID of the connected backend (Julien Rouhaud)
+
+
+
+
+
+ Introduce a feature whereby the CONTEXT field of messages
+ can be suppressed, either always or only for non-error messages
+ (Pavel Stehule)
+
+
+ Printing CONTEXT only for errors is now the default
+ behavior. This can be changed by setting the special variable
+ SHOW_CONTEXT.
+
+
+
+
+
+
+
+
+
<xref linkend="pgbench">
+
+
+
+
+
+ SQL commands in
pgbench scripts are now ended by+ semicolons, not newlines (Kyotaro Horiguchi, Tom Lane)
+
+
+ This change allows SQL commands in scripts to span multiple lines.
+ Existing custom scripts will need to be modified to add a semicolon
+ at the end of each line that does not have one already. (Doing so
+ does not break the script for use with older versions
+
+
+
+
+
+ Support some built-in
+ functions in expressions in backslash commands (Fabien Coelho)
+
+
+
+
+
+ Replace \setrandom with built-in functions (Fabien Coelho)
+
+
+ The new built-in functions include random(),
+ random_exponential(), and random_gaussian(),
+ which perform the same work as \setrandom, but are easier
+ to use since they can be embedded in larger expressions. Since these
+ additions have made \setrandom obsolete, remove it.
+
+
+
+
+
+ Allow invocation of multiple copies of the built-in scripts, not only
+ custom scripts (Fabien Coelho)
+
+
+ This is done with the new
+ to
+
+
+
+
+
+ Allow changing the selection probabilities (weights) for scripts
+ (Fabien Coelho)
+
+
+ When multiple scripts are specified, each
pgbench+ transaction randomly chooses one to execute. Formerly this was
+ always done with uniform probability, but now different selection
+ probabilities can be specified for different scripts.
+
+
+
+
+
+ Collect statistics for each script in a multi-script run
+ (Fabien Coelho)
+
+
+ This feature adds an intermediate level of detail to existing global
+ and per-command statistics printouts.
+
+
+
+
+
+ Add a
+ Unix epoch timestamps, instead of time since the run started
+ (Fabien Coelho)
+
+
+
+
+
+ Allow the number of client connections (
+ exact multiple of the number of threads (
+ (Fabien Coelho)
+
+
+
+
+
+ When the
+ the specified time (Fabien Coelho)
+
+
+ Previously, specifying a low transaction rate could
+ cause
pgbench to wait significantly longer than that.+
+
+
+
+
+
+
+
+
+
+
Server Applications
+
+
+
+
+
+ Improve error reporting during
initdb's post-bootstrap+ phase, by not reporting the entire input file as the failing
+ query (Tom Lane)
+
+
+
+
+
+ Speed up
initdb by using just one standalone-backend+ session for all the post-bootstrap steps (Tom Lane)
+
+
+
+
+
+ Improve
pg_rewind so that it can work when the+ target timeline changes (Alexander Korotkov)
+
+
+ This allows, for example, rewinding a promoted standby back to
+ some state of the old master's timeline.
+
+
+
+
+
+
+
+
+
Source Code
+
+
+
+
+
+ Remove obsolete heap_formtuple/heap_modifytuple/heap_deformtuple
+ functions (Peter Geoghegan)
+
+
+
+
+
+ Unconditionally use static inline functions in header
+ files (Andres Freund)
+
+
+ This may result in warnings and/or wasted code space with very old
+ compilers, but the notational improvement seems worth it.
+
+
+
+
+
+ Improve TAP testing infrastructure
+ (Michael Paquier, Craig Ringer, Álvaro Herrera)
+
+
+ Notably, it is now possible to test recovery scenarios using this
+ infrastructure.
+
+
+
+
+
+ Make trace_lwlocks identify individual locks by name
+ (Robert Haas)
+
+
+
+
+
+ Improve
psql's tab-completion code infrastructure+ (Thomas Munro, Michael Paquier)
+
+
+ Tab-completion rules are now considerably easier to write, and more
+ compact.
+
+
+
+
+
+ Nail the pg_shseclabel system catalog into cache,
+ so that it is available for access during connection authentication
+ (Adam Brightwell)
+
+
+ The core code doesn't use this catalog for authentication, but
+ extensions might wish to consult it.
+
+
+
+
+
+ Restructure index access method API to hide most of it at the C level
+ (Alexander Korotkov)
+
+
+ This change modernizes the index AM API to look more like the designs
+ we've adopted for foreign data wrappers and tablesample handlers.
+ This simplifies the C code and should make it more feasible to define
+ index access methods in installable extensions. A consequence is
+ that most of the columns of the pg_am system catalog
+ have disappeared.
+
+
+
+
+
+ Add pg_init_privs system catalog to hold original
+ privileges of
initdb-created and extension-created+ objects (Stephen Frost)
+
+
+ This infrastructure allows
pg_dump to dump changes+ that an installation may have made in privileges attached to system
+ objects. Formerly, such changes would be lost in a dump and reload,
+ but now they can be preserved.
+
+
+
+
+
+ Generalize the SortSupport for text so that it can be
+ used by other types such as bpchar (Peter Geoghegan)
+
+
+
+
+
+ Change the way that extensions allocate custom LWLocks
+ (Amit Kapila, Robert Haas)
+
+
+ The RequestAddinLWLocks() function is removed, and
+ replaced by RequestNamedLWLockTranche(). This allows
+ better identification of custom LWLocks, and is less error-prone.
+
+
+
+
+
+ Improve the isolation tester to allow multiple sessions to wait
+ concurrently, allowing testing of deadlock scenarios (Robert Haas)
+
+
+
+
+
+ Introduce extensible node types (KaiGai Kohei)
+
+
+ This change allows FDWs or custom scan providers to store data in a
+ plan tree in a more convenient format than was previously possible.
+
+
+
+
+
+ Make the planner deal with post-scan/join query steps by generating
+ and comparing Paths, replacing a lot of very ad-hoc logic (Tom Lane)
+
+
+ This change provides only marginal user-visible improvements today,
+ but it enables future work on a lot of upper-planner improvements
+ that were impractical to tackle in the old code structure.
+
+
+
+
+
+ Support partial aggregation (David Rowley, Simon Riggs)
+
+
+ This change allows the computation of an aggregate function to be
+ split into separate parts, for example so that parallel worker
+ processes can cooperate on computing an aggregate. In future it
+ might allow aggregation across local and remote data to occur
+ partially on the remote end.
+
+
+
+
+
+ Add a generic command progress reporting facility (Vinayak Pokale,
+ Rahila Syed, Amit Langote, Robert Haas)
+
+
+
+
+
+ Separate out
psql's flex lexer to make it usable by+ other client programs too (Tom Lane, Kyotaro Horiguchi)
+
+
+ This eliminates code duplication for programs that need to be able
+ to parse SQL commands well enough to identify command boundaries.
+ Doing that in full generality is more painful than one could wish,
+ and up to now only
psql has really gotten it right+ among our supported client programs.
+
+
+ A new source-code subdirectory src/fe_utils/ has been
+ created to hold this and other code that's shared across our client
+ programs. Formerly such sharing was accomplished by symlinking or
+ copying source files at build time, which was ugly and required
+ duplicate compilation work.
+
+
+
+
+
+ Introduce WaitEventSet API to allow efficient waiting for event
+ sets that usually don't change from one wait to the next
+ (Andres Freund, Amit Kapila)
+
+
+
+
+
+ Add a generic interface for writing WAL records
+ (Alexander Korotkov, Petr Jelínek, Markus Nullmeier)
+
+
+ This change allows extensions to write WAL records for changes to
+ pages with standard layout. The problem of needing to replay WAL
+ without access to the extension is solved by having generic replay
+ code. This allows extensions to implement, for example, index access
+ methods and have WAL support for them.
+
+
+
+
+
+ Support generic WAL messages for logical decoding
+ (Petr Jelínek, Andres Freund)
+
+
+ This feature allows extensions to insert data into the WAL stream
+ that can be read by logical-decoding plugins, but is not connected to
+ physical data restoration.
+
+
+
+
+
+ Allow SP-GiST operator classes to store an arbitrary traversal
+ value while descending the index (Alexander Lebedev, Teodor Sigaev)
+
+
+ This is somewhat like the reconstructed value, but it could
+ be any arbitrary chunk of data, it need not be of the same data type
+ as the indexed column.
+
+
+
+
+
+ Introduce a LOG_SERVER_ONLY message level
+ for ereport() (David Steele)
+
+
+ This level acts like LOG except that the message is never
+ sent to the client. It's meant for use in auditing and similar
+ applications.
+
+
+
+
+
+
+
+
+
Additional Modules
+
+
+
+
+
+ Add configuration parameter auto_explain.sample_rate
+ to allow contrib/auto_explain to capture just a
+ configurable fraction of all queries (Craig Ringer, Julien Rouhaud)
+
+
+ This allows reduction of overhead for heavy query traffic, while
+ still getting useful information on average.
+
+
+
+
+
+ Add contrib/bloom module that implements an index access
+ method based on Bloom filtering (Teodor Sigaev, Alexander Korotkov)
+
+
+ This is primarily a proof-of-concept for non-core index access
+ methods, but it could be useful in its own right for queries that
+ involve searches on many columns.
+
+
+
+
+
+ In contrib/cube, introduce distance operators for cubes,
+ and support kNN-style searches in GiST indexes on cube columns
+ (Stas Kelvich)
+
+
+
+
+
+ Make contrib/hstore's hstore_to_jsonb_loose()
+ and hstore_to_json_loose() functions agree on what's a
+ number (Tom Lane)
+
+
+ Previously, hstore_to_jsonb_loose() would convert
+ numeric-looking strings to JSON numbers, rather than strings, even if
+ they did not exactly match the JSON syntax specification for numbers.
+ This was inconsistent with hstore_to_json_loose(), so
+ tighten the test to match the JSON syntax.
+
+
+
+
+
+ Add selectivity estimation functions for contrib/intarray
+ operators, to improve plans for queries using those operators (Uriy
+ Zhuravlev, Alexander Korotkov)
+
+
+
+
+
+ Make contrib/pageinspect's heap_page_items()
+ function show the raw data in each tuple, and add new
+ functions tuple_data_split()
+ and heap_page_item_attrs() for inspection of individual
+ tuple fields (Nikolay Shaplov)
+
+
+
+
+
+ Add an optional S2K iteration count parameter
+ to contrib/pgcrypto's pgp_sym_encrypt()
+ function (Jeff Janes)
+
+
+
+
+
+ Add support for word similarity
+ to contrib/pg_trgm
+ (Alexander Korotkov, Artur Zakirov)
+
+
+ These functions and operators measure the similarity between one
+ string and the most similar single word of another string.
+
+
+
+
+
+ Add configuration parameter pg_trgm.similarity_threshold
+ for contrib/pg_trgm's similarity threshold
+ (Artur Zakirov)
+
+
+ This threshold has always been configurable, but formerly it was
+ controlled by special-purpose functions set_limit()
+ and show_limit(). Those are now deprecated.
+
+
+
+
+
+ Improve contrib/pg_trgm's GIN operator class to speed up
+ index searches in which both common and rare keys appear (Jeff Janes)
+
+
+
+
+
+ Improve performance of similarity searches in
+ contrib/pg_trgm GIN indexes (Christophe Fornaroli)
+
+
+
+
+
+ Add contrib/pg_visibility module to allow examining
+ table visibility maps (Robert Haas)
+
+
+
+
+
+ Add ssl_extension_info() function
+ to contrib/sslinfo, to print information about SSL
+ extensions present in the X509 certificate used for the current
+ connection (Dmitry Voronin)
+
+
+
+
+
+ Extend contrib/unaccent's
+ standard unaccent.rules file to handle all diacritics
+ known to Unicode, and expand ligatures correctly
+ (Thomas Munro, Leonard Benedetti)
+
+
+ The previous version omitted some less-common letters with diacritic
+ marks. It now also expands ligatures into separate letters.
+ Installations that use this rules file may wish to
+ rebuild tsvector columns and indexes that depend on the
+ result.
+
+
+
+
+
+
+
<filename>postgres_fdw</>
+
+
+
+
+
+ Allow extension-provided operators and functions to be sent for
+ remote execution, if the extension is whitelisted in the foreign
+ server's options (Paul Ramsey)
+
+
+ Users can enable this feature when the extension is known to exist in
+ a compatible version in the remote database. It allows more efficient
+ execution of queries involving extension operators.
+
+
+
+
+
+ Use a single foreign-server connection for local user IDs that all
+ map to the same remote user (Ashutosh Bapat)
+
+
+
+
+
+ Allow the fetch size to be set as a server or table option
+ (Corey Huinker)
+
+
+ Formerly, postgres_fdw always fetched 100 rows at a time
+ from remote queries; now that behavior is adjustable.
+
+
+
+
+
+ Consider performing sorts on the remote server (Ashutosh Bapat)
+
+
+
+
+
+ Push down joins to the remote server when possible (Shigeru Hanada,
+ Ashutosh Bapat)
+
+
+
+
+
+ When feasible, perform UPDATE or DELETE
+ entirely on the remote server (Etsuro Fujita)
+
+
+ Formerly, this involved sending a SELECT FOR UPDATE
+ command and then updating or deleting the selected rows one-by-one.
+ While that's still necessary if the operation requires any local
+ processing, it can now be done remotely if all elements of the query
+ are safe to send to the remote server.
+
+
+
+
+
+ Transmit query cancellation requests to the remote server
+ (Michael Paquier)
+
+
+ Previously, a local query cancellation request did nothing to cause
+ an already-sent remote query to terminate early.
+
+
+
+
+
+
+
+
+
+
+
+
projects / postgresql.git / commitdiff