E.18. Release 10
Release date: 2017-10-05
Major enhancements in PostgreSQL 10 include:
Logical replication using publish/subscribe
Declarative table partitioning
Improved query parallelism
Significant general performance improvements
Stronger password authentication based on SCRAM-SHA-256
Improved monitoring and control
The above items are explained in more detail in the sections below.
E.18.2. Migration to Version 10
Version 10 contains a number of changes that may affect compatibility with previous releases. Observe the following incompatibilities:
Hash indexes must be rebuilt after pg_upgrade-ing from any previous major PostgreSQL version (Mithun Cy, Robert Haas, Amit Kapila)
Major hash index improvements necessitated this requirement. pg_upgrade will create a script to assist with this.
Rename write-ahead log directory
pg_wal, and rename transaction status directory
Users have occasionally thought that these directories contained only inessential log files, and proceeded to remove write-ahead log files or transaction status files manually, causing irrecoverable data loss. These name changes are intended to discourage such errors in future.
Rename SQL functions, tools, and options that reference “xlog” to “wal” (Robert Haas)
pg_switch_wal(), pg_receivexlog becomes pg_receivewal, and
--waldir. This is for consistency with the change of the
pg_xlogdirectory name; in general, the “xlog” terminology is no longer used in any user-facing places.
Rename WAL-related functions and views to use
There was previously an inconsistent mixture of the two terminologies.
Change the implementation of set-returning functions appearing in a query's
SELECTlist (Andres Freund)
Set-returning functions are now evaluated before evaluation of scalar expressions in the
SELECTlist, much as though they had been placed in a
LATERAL FROM-clause item. This allows saner semantics for cases where multiple set-returning functions are present. If they return different numbers of rows, the shorter results are extended to match the longest result by adding nulls. Previously the results were cycled until they all terminated at the same time, producing a number of rows equal to the least common multiple of the functions' periods. In addition, set-returning functions are now disallowed within
COALESCEconstructs. For more information see Section 36.4.8.
Use standard row constructor syntax in
UPDATE ... SET ((Tom Lane)
row_constructorcan now begin with the keyword
ROW; previously that had to be omitted. If just one column name appears in the
column_list, then the
row_constructornow must use the
ROWkeyword, since otherwise it is not a valid row constructor but just a parenthesized expression. Also, an occurrence of
row_constructoris now expanded into multiple columns, as occurs in other uses of
ALTER TABLE ... ADD PRIMARY KEYmarks columns
NOT NULL, that change now propagates to inheritance child tables as well (Michael Paquier)
Prevent statement-level triggers from firing more than once per statement (Tom Lane)
Cases involving writable CTEs updating the same table updated by the containing statement, or by another writable CTE, fired
AFTER STATEMENTtriggers more than once. Also, if there were statement-level triggers on a table affected by a foreign key enforcement action (such as
ON DELETE CASCADE), they could fire more than once per outer SQL statement. This is contrary to the SQL standard, so change it.
Move sequences' metadata fields into a new
pg_sequencesystem catalog (Peter Eisentraut)
A sequence relation now stores only the fields that can be modified by
nextval(), that is
is_called. Other sequence properties, such as the starting value and increment, are kept in a corresponding row of the
ALTER SEQUENCEupdates are now fully transactional, implying that the sequence is locked until commit. The
setval()functions remain nontransactional.
The main incompatibility introduced by this change is that selecting from a sequence relation now returns only the three fields named above. To obtain the sequence's other properties, applications must look into
pg_sequence. The new system view
pg_sequencescan also be used for this purpose; it provides column names that are more compatible with existing code.
Also, sequences created for
SERIALcolumns now generate positive 32-bit wide values, whereas previous versions generated 64-bit wide values. This has no visible effect if the values are only stored in a column.
The output of psql's
\dcommand for a sequence has been redesigned, too.
Make pg_basebackup stream the WAL needed to restore the backup by default (Magnus Hagander)
This changes pg_basebackup's
stream. An option value
nonehas been added to reproduce the old behavior. The pg_basebackup option
-xhas been removed (instead, use
Change how logical replication uses
In previous releases, a logical replication connection required the
replicationkeyword in the database column. As of this release, logical replication matches a normal entry with a database name or keywords such as
all. Physical replication continues to use the
replicationkeyword. Since built-in logical replication is new in this release, this change only affects users of third-party logical replication plugins.
Make all pg_ctl actions wait for completion by default (Peter Eisentraut)
Previously some pg_ctl actions didn't wait for completion, and required the use of
-wto do so.
Change the default value of the log_directory server parameter from
Add configuration option ssl_dh_params_file to specify file name for custom OpenSSL DH parameters (Heikki Linnakangas)
This replaces the hardcoded, undocumented file name
dh1024.pem. Note that
dh1024.pemis no longer examined by default; you must set this option if you want to use custom DH parameters.
Increase the size of the default DH parameters used for OpenSSL ephemeral DH ciphers to 2048 bits (Heikki Linnakangas)
The size of the compiled-in DH parameters has been increased from 1024 to 2048 bits, making DH key exchange more resistant to brute-force attacks. However, some old SSL implementations, notably some revisions of Java Runtime Environment version 6, will not accept DH parameters longer than 1024 bits, and hence will not be able to connect over SSL. If it's necessary to support such old clients, you can use custom 1024-bit DH parameters instead of the compiled-in defaults. See ssl_dh_params_file.
Remove the ability to store unencrypted passwords on the server (Heikki Linnakangas)
The password_encryption server parameter no longer supports
UNENCRYPTEDoption is no longer supported in
CREATE/ALTER USER ... PASSWORD. Similarly, the
--unencryptedoption has been removed from createuser. Unencrypted passwords migrated from older versions will be stored encrypted in this release. The default setting for
min_parallel_relation_size, which was found to be too generic.
Don't downcase unquoted text within shared_preload_libraries and related server parameters (QL Zhuo)
These settings are really lists of file names, but they were previously treated as lists of SQL identifiers, which have different parsing rules.
sql_inheritanceserver parameter (Robert Haas)
Changing this setting from the default value caused queries referencing parent tables to not include child tables. The SQL standard requires them to be included, however, and this has been the default since PostgreSQL 7.1.
Allow multi-dimensional arrays to be passed into PL/Python functions, and returned as nested Python lists (Alexey Grishchenko, Dave Cramer, Heikki Linnakangas)
This feature requires a backwards-incompatible change to the handling of arrays of composite types in PL/Python. Previously, you could return an array of composite values by writing, e.g.,
[[col1, col2], [col1, col2]]; but now that is interpreted as a two-dimensional array. Composite types in arrays must now be written as Python tuples, not lists, to resolve the ambiguity; that is, write
[(col1, col2), (col1, col2)]instead.
Remove PL/Tcl's “module” auto-loading facility (Tom Lane)
Remove pg_dump/pg_dumpall support for dumping from pre-8.0 servers (Tom Lane)
Users needing to dump from pre-8.0 servers will need to use dump programs from PostgreSQL 9.6 or earlier. The resulting output should still load successfully into newer servers.
Remove support for floating-point timestamps and intervals (Tom Lane)
This removes configure's
--disable-integer-datetimesoption. Floating-point timestamps have few advantages and have not been the default since PostgreSQL 8.3.
Remove server support for client/server protocol version 1.0 (Tom Lane)
This protocol hasn't had client support since PostgreSQL 6.3.
contrib/tsearch2module (Robert Haas)
This module provided compatibility with the version of full text search that shipped in pre-8.3 PostgreSQL releases.
Remove createlang and droplang command-line applications (Peter Eisentraut)
These had been deprecated since PostgreSQL 9.1. Instead, use
Remove support for version-0 function calling conventions (Andres Freund)
Extensions providing C-coded functions must now conform to version 1 calling conventions. Version 0 has been deprecated since 2001.
Below you will find a detailed account of the changes between PostgreSQL 10 and the previous major release.
E.184.108.40.206. Parallel Queries
Support parallel B-tree index scans (Rahila Syed, Amit Kapila, Robert Haas, Rafia Sabih)
This change allows B-tree index pages to be searched by separate parallel workers.
Support parallel bitmap heap scans (Dilip Kumar)
This allows a single index scan to dispatch parallel workers to process different areas of the heap.
Allow merge joins to be performed in parallel (Dilip Kumar)
Allow non-correlated subqueries to be run in parallel (Amit Kapila)
Improve ability of parallel workers to return pre-sorted data (Rushabh Lathia)
Increase parallel query usage in procedural language functions (Robert Haas, Rafia Sabih)
Add max_parallel_workers server parameter to limit the number of worker processes that can be used for query parallelism (Julien Rouhaud)
This parameter can be set lower than max_worker_processes to reserve worker processes for purposes other than parallel queries.
Enable parallelism by default by changing the default setting of max_parallel_workers_per_gather to
Add write-ahead logging support to hash indexes (Amit Kapila)
This makes hash indexes crash-safe and replicatable. The former warning message about their use is removed.
Improve hash index performance (Amit Kapila, Mithun Cy, Ashutosh Sharma)
Add SP-GiST index support for
CIDRdata types (Emre Hasegeli)
Add option to allow BRIN index summarization to happen more aggressively (Álvaro Herrera)
CREATE INDEXoption enables auto-summarization of the previous BRIN page range when a new page range is created.
Add functions to remove and re-add BRIN summarization for BRIN index ranges (Álvaro Herrera)
The new SQL function
brin_summarize_range()updates BRIN index summarization for a specified range and
brin_desummarize_range()removes it. This is helpful to update summarization of a range that is now smaller due to
Improve accuracy in determining if a BRIN index scan is beneficial (David Rowley, Emre Hasegeli)
Allow faster GiST inserts and updates by reusing index space more efficiently (Andrey Borodin)
Reduce page locking during vacuuming of GIN indexes (Andrey Borodin)
Reduce locking required to change table parameters (Simon Riggs, Fabrízio Mello)
For example, changing a table's effective_io_concurrency setting can now be done with a more lightweight lock.
Allow tuning of predicate lock promotion thresholds (Dagfinn Ilmari Mannsåker)
Add multi-column optimizer statistics to compute the correlation ratio and number of distinct values (Tomas Vondra, David Rowley, Álvaro Herrera)
Improve performance of queries affected by row-level security restrictions (Tom Lane)
The optimizer now has more knowledge about where it can place RLS filter conditions, allowing better plans to be generated while still enforcing the RLS conditions safely.
E.220.127.116.11. General Performance
Speed up aggregate functions that calculate a running sum using
numeric-type arithmetic, including some variants of
Improve performance of character encoding conversions by using radix trees (Kyotaro Horiguchi, Heikki Linnakangas)
Reduce expression evaluation overhead during query execution, as well as plan node calling overhead (Andres Freund)
This is particularly helpful for queries that process many rows.
Allow hashed aggregation to be used with grouping sets (Andrew Gierth)
Use uniqueness guarantees to optimize certain join types (David Rowley)
Improve sort performance of the
macaddrdata type (Brandur Leach)
Reduce statistics tracking overhead in sessions that reference many thousands of relations (Aleksander Alekseev)
Allow explicit control over
EXPLAIN's display of planning and execution time (Ashutosh Bapat)
By default planning and execution time are displayed by
EXPLAIN ANALYZEand are not displayed in other cases. The new
SUMMARYallows explicit control of this.
Add default monitoring roles (Dave Page)
pg_stat_scan_tablesallow simplified permission configuration.
Properly update the statistics collector during
REFRESH MATERIALIZED VIEW(Jim Mlodgenski)
Change the default value of log_line_prefix to include current timestamp (with milliseconds) and the process ID in each line of postmaster log output (Christoph Berg)
The previous default was an empty prefix.
Add functions to return the log and WAL directory contents (Dave Page)
pg_current_logfile()to read logging collector's current stderr and csvlog output file names (Gilles Darold)
Report the address and port number of each listening socket in the server log during postmaster startup (Tom Lane)
Also, when logging failure to bind a listening socket, include the specific address we attempted to bind to.
Reduce log chatter about the starting and stopping of launcher subprocesses (Tom Lane)
These are now
Reduce message verbosity of lower-numbered debug levels controlled by log_min_messages (Robert Haas)
This also changes the verbosity of client_min_messages debug levels.
pg_stat_activityreporting of low-level wait states (Michael Paquier, Robert Haas, Rushabh Lathia)
This change enables reporting of numerous low-level wait conditions, including latch waits, file reads/writes/fsyncs, client reads/writes, and synchronous replication.
Show auxiliary processes, background workers, and walsender processes in
pg_stat_activity(Kuntal Ghosh, Michael Paquier)
This simplifies monitoring. A new column
backend_typeidentifies the process type.
pg_stat_activityto show the SQL query being executed by parallel workers (Rafia Sabih)
This makes the output more consistent.
Add SCRAM-SHA-256 support for password negotiation and storage (Michael Paquier, Heikki Linnakangas)
This provides better security than the existing
md5negotiation and storage method.
Change the password_encryption server parameter from
This was necessary to support additional password hashing options.
pg_hba_file_rulesto display the contents of
This shows the file contents, not the currently active settings.
Support multiple RADIUS servers (Magnus Hagander)
All the RADIUS related parameters are now plural and support a comma-separated list of servers.
E.18.104.22.168. Server Configuration
Allow SSL configuration to be updated during configuration reload (Andreas Karlsson, Tom Lane)
This allows SSL to be reconfigured without a server restart, by using
SELECT pg_reload_conf(), or sending a
SIGHUPsignal. However, reloading the SSL configuration does not work if the server's SSL key requires a passphrase, as there is no way to re-prompt for the passphrase. The original configuration will apply for the life of the postmaster in that case.
Make the maximum value of bgwriter_lru_maxpages effectively unlimited (Jim Nasby)
After creating or unlinking files, perform an fsync on their parent directory (Michael Paquier)
This reduces the risk of data loss after a power failure.
Prevent unnecessary checkpoints and WAL archiving on otherwise-idle systems (Michael Paquier)
Add wal_consistency_checking server parameter to add details to WAL that can be sanity-checked on the standby (Kuntal Ghosh, Robert Haas)
Any sanity-check failure generates a fatal error on the standby.
Increase the maximum configurable WAL segment size to one gigabyte (Beena Emerson)
A larger WAL segment size allows for fewer archive_command invocations and fewer WAL files to manage.
E.18.3.2. Replication and Recovery
Add the ability to logically replicate tables to standby servers (Petr Jelinek)
Logical replication allows more flexibility than physical replication does, including replication between different major versions of PostgreSQL and selective replication.
Allow waiting for commit acknowledgment from standby servers irrespective of the order they appear in synchronous_standby_names (Masahiko Sawada)
Previously the server always waited for the active standbys that appeared first in
synchronous_standby_names. The new
ANYallows waiting for any number of standbys irrespective of their ordering. This is known as quorum commit.
Reduce configuration changes necessary to perform streaming backup and replication (Magnus Hagander, Dang Minh Huong)
Enable replication from localhost connections by default in
pg_hba.conf's replication connection lines were commented out by default. This is particularly useful for pg_basebackup.
Add columns to
pg_stat_replicationto report replication delay times (Thomas Munro)
The new columns are
Allow specification of the recovery stopping point by Log Sequence Number (LSN) in
Previously the stopping point could only be selected by timestamp or XID.
Allow users to disable
pg_stop_backup()'s waiting for all WAL to be archived (David Steele)
An optional second argument to
pg_stop_backup()controls that behavior.
Allow creation of temporary replication slots (Petr Jelinek)
Temporary slots are automatically removed on session exit or error.
Improve performance of hot standby replay with better tracking of Access Exclusive locks (Simon Riggs, David Rowley)
Speed up two-phase commit recovery performance (Stas Kelvich, Nikhil Sontakke, Michael Paquier)
XMLTABLEfunction that converts
XML-formatted data into a row set (Pavel Stehule, Álvaro Herrera)
Fix regular expressions' character class handling for large character codes, particularly Unicode characters above
Previously, such characters were never recognized as belonging to locale-dependent character classes such as
E.18.3.4. Utility Commands
Add table partitioning syntax that automatically creates partition constraints and handles routing of tuple insertions and updates (Amit Langote)
The syntax supports range and list partitioning.
AFTERtrigger transition tables to record changed rows (Kevin Grittner, Thomas Munro)
Transition tables are accessible from triggers written in server-side languages.
Allow restrictive row-level security policies (Stephen Frost)
Previously all security policies were permissive, meaning that any matching policy allowed access. A restrictive policy must match for access to be granted. These policy types can be combined.
When creating a foreign-key constraint, check for
REFERENCESpermission on only the referenced table (Tom Lane)
REFERENCESpermission on the referencing table was also required. This appears to have stemmed from a misreading of the SQL standard. Since creating a foreign key (or any other type of) constraint requires ownership privilege on the constrained table, additionally requiring
REFERENCESpermission seems rather pointless.
Allow default permissions on schemas (Matheus Oliveira)
This is done using the
ALTER DEFAULT PRIVILEGEScommand.
CREATE SEQUENCE AScommand to create a sequence matching an integer data type (Peter Eisentraut)
This simplifies the creation of sequences matching the range of base columns.
COPYon views with
INSTEAD INSERTtriggers (Haribabu Kommi)
The triggers are fed the data rows read by
Allow the specification of a function name without arguments in DDL commands, if it is unique (Peter Eisentraut)
For example, allow
DROP FUNCTIONon a function name without arguments if there is only one function with that name. This behavior is required by the SQL standard.
Allow multiple functions, operators, and aggregates to be dropped with a single
DROPcommand (Peter Eisentraut)
VACUUM VERBOSEreport the number of skipped frozen pages and oldest xmin (Masahiko Sawada, Simon Riggs)
This information is also included in log_autovacuum_min_duration output.
Improve speed of
VACUUM's removal of trailing empty heap pages (Claudio Freire, Álvaro Herrera)
E.18.3.5. Data Types
Add full text search support for
to_tsvector()can now be used on these data types.
Add support for EUI-64 MAC addresses, as a new data type
This complements the existing support for EUI-48 MAC addresses (type
Add identity columns for assigning a numeric value to columns on insert (Peter Eisentraut)
These are similar to
SERIALcolumns, but are SQL standard compliant.
ENUMvalues to be renamed (Dagfinn Ilmari Mannsåker)
This uses the syntax
ALTER TYPE ... RENAME VALUE.
Properly treat array pseudotypes (
anyarray) as arrays in
Previously columns declared as
anyarray(particularly those in the
pg_statsview) were converted to
JSONstrings rather than arrays.
Add operators for multiplication and division of
int8values (Peter Eisentraut)
Previously such cases would result in converting the
float8and then using the
float8operators. The new behavior avoids possible precision loss. But note that division of
int8now truncates the quotient, like other integer-division cases, while the previous behavior would have rounded.
Check for overflow in the
moneytype's input function (Peter Eisentraut)
regexp_match()function (Emre Hasegeli)
This is similar to
regexp_matches(), but it only returns results from the first match so it does not need to return a set, making it easier to use for simple cases.
Add a version of
jsonb's delete operator that takes an array of keys to delete (Magnus Hagander)
json_populate_record()and related functions process JSON arrays and objects recursively (Nikita Glukhov)
With this change, array-type fields in the destination SQL type are properly converted from JSON arrays, and composite-type fields are properly converted from JSON objects. Previously, such cases would fail because the text representation of the JSON value would be fed to
record_in(), and its syntax would not match what those input functions expect.
txid_current_if_assigned()to return the current transaction ID or
NULLif no transaction ID has been assigned (Craig Ringer)
This is different from
txid_current(), which always returns a transaction ID, assigning one if necessary. Unlike that function, this function can be run on standby servers.
txid_status()to check if a transaction was committed (Craig Ringer)
This is useful for checking after an abrupt disconnection whether your previous transaction committed and you just didn't receive the acknowledgment.
make_date()to interpret negative years as BC years (Álvaro Herrera)
to_date()reject out-of-range input fields (Artur Zakirov)
For example, previously
to_date('2009-06-40','YYYY-MM-DD')was accepted and returned
2009-07-10. It will now generate an error.
E.18.3.7. Server-Side Languages
execute()functions to be called as methods of their plan-object arguments (Peter Eisentraut)
This allows a more object-oriented programming style.
GET DIAGNOSTICSstatement to retrieve values into array elements (Tom Lane)
Previously, a syntactic restriction prevented the target variable from being an array element.
Allow PL/Tcl functions to return composite types and sets (Karl Lehenbauer)
Add a subtransaction command to PL/Tcl (Victor Wagner)
This allows PL/Tcl queries to fail without aborting the entire function.
E.18.3.8. Client Interfaces
Allow specification of multiple host names or addresses in libpq connection strings and URIs (Robert Haas, Heikki Linnakangas)
libpq will connect to the first responsive server in the list.
Allow libpq connection strings and URIs to request a read/write host, that is a master server rather than a standby server (Victor Wagner, Mithun Cy)
This is useful when multiple host names are specified. It is controlled by libpq connection parameter
Allow the password file name to be specified as a libpq connection parameter (Julian Markwort)
Previously this could only be specified via an environment variable.
PQencryptPasswordConn()to allow creation of more types of encrypted passwords on the client side (Michael Paquier, Heikki Linnakangas)
Change ecpg preprocessor version from 4.12 to 10 (Tom Lane)
Henceforth the ecpg version will match the PostgreSQL distribution version number.
E.18.3.9. Client Applications
Add conditional branch support to psql (Corey Huinker)
This feature adds psql meta-commands
\endif. This is primarily helpful for scripting.
\gxmeta-command to execute (
\g) a query in expanded mode (
\x) (Christoph Berg)
Expand psql variable references in backtick-executed strings (Tom Lane)
This is particularly useful in the new psql conditional branch commands.
Prevent psql's special variables from being set to invalid values (Daniel Vérité, Tom Lane)
Previously, setting one of psql's special variables to an invalid value silently resulted in the default behavior.
\seton a special variable now fails if the proposed new value is invalid. As a special exception,
\setwith an empty or omitted new value, on a boolean-valued special variable, still has the effect of setting the variable to
on; but now it actually acquires that value rather than an empty string.
\unseton a special variable now explicitly sets the variable to its default value, which is also the value it acquires at startup. In sum, a control variable now always has a displayable value that reflects what psql is actually doing.
Add variables showing server version and psql version (Fabien Coelho)
\d(display relation) and
\dD(display domain) commands to show collation, nullable, and default properties in separate columns (Peter Eisentraut)
Previously they were shown in a single “Modifiers” column.
Make the various
\dcommands handle no-matching-object cases more consistently (Daniel Gustafsson)
They now all print the message about that to stderr, not stdout, and the message wording is more consistent.
Improve psql's tab completion (Jeff Janes, Ian Barwick, Andreas Karlsson, Sehrope Sarkuni, Thomas Munro, Kevin Grittner, Dagfinn Ilmari Mannsåker)
Add pgbench option
--log-prefixto control the log file prefix (Masahiko Sawada)
Allow pgbench's meta-commands to span multiple lines (Fabien Coelho)
A meta-command can now be continued onto the next line by writing backslash-return.
Remove restriction on placement of
-Moption relative to other command line options (Tom Lane)
E.18.3.10. Server Applications
Add pg_receivewal option
--compressto specify compression (Michael Paquier)
Add pg_recvlogical option
--endposto specify the ending position (Craig Ringer)
This complements the existing
Rename initdb options
--nosyncto be spelled
--no-sync(Vik Fearing, Peter Eisentraut)
The old spellings are still supported.
Allow pg_restore to exclude schemas (Michael Banck)
This adds a new
--no-blobsoption to pg_dump (Guillaume Lelarge)
This suppresses dumping of large objects.
Add pg_dumpall option
--no-role-passwordsto omit role passwords (Robins Tharakan, Simon Riggs)
This allows use of pg_dumpall by non-superusers; without this option, it fails due to inability to read passwords.
Support using synchronized snapshots when dumping from a standby server (Petr Jelinek)
fsync()on the output files generated by pg_dump and pg_dumpall (Michael Paquier)
This provides more security that the output is safely stored on disk before the program exits. This can be disabled with the new
Allow pg_basebackup to stream write-ahead log in tar mode (Magnus Hagander)
The WAL will be stored in a separate tar file from the base backup.
Make pg_basebackup use temporary replication slots (Magnus Hagander)
Temporary replication slots will be used by default when pg_basebackup uses WAL streaming with default options.
Be more careful about fsync'ing in all required places in pg_basebackup and pg_receivewal (Michael Paquier)
Add pg_basebackup option
--no-syncto disable fsync (Michael Paquier)
Improve pg_basebackup's handling of which directories to skip (David Steele)
Add wait option for pg_ctl's promote operation (Peter Eisentraut)
Add long options for pg_ctl wait (
--wait) and no-wait (
--no-wait) (Vik Fearing)
Add long option for pg_ctl server options (
--options) (Peter Eisentraut)
pg_ctl start --waitdetect server-ready by watching
postmaster.pid, not by attempting connections (Tom Lane)
The postmaster has been changed to report its ready-for-connections status in
postmaster.pid, and pg_ctl now examines that file to detect whether startup is complete. This is more efficient and reliable than the old method, and it eliminates postmaster log entries about rejected connection attempts during startup.
Reduce pg_ctl's reaction time when waiting for postmaster start/stop (Tom Lane)
pg_ctl now probes ten times per second when waiting for a postmaster state change, rather than once per second.
Ensure that pg_ctl exits with nonzero status if an operation being waited for does not complete within the timeout (Peter Eisentraut)
promoteoperations now return exit status 1, not 0, in such cases. The
stopoperation has always done that.
E.18.3.11. Source Code
Change to two-part release version numbering (Peter Eisentraut, Tom Lane)
Release numbers will now have two parts (e.g.,
10.1) rather than three (e.g.,
9.6.3). Major versions will now increase just the first number, and minor releases will increase just the second number. Release branches will be referred to by single numbers (e.g.,
9.6). This change is intended to reduce user confusion about what is a major or minor release of PostgreSQL.
Improve behavior of pgindent (Piotr Stefaniak, Tom Lane)
We have switched to a new version of pg_bsd_indent based on recent improvements made by the FreeBSD project. This fixes numerous small bugs that led to odd C code formatting decisions. Most notably, lines within parentheses (such as in a multi-line function call) are now uniformly indented to match the opening paren, even if that would result in code extending past the right margin.
Allow the ICU library to optionally be used for collation support (Peter Eisentraut)
The ICU library has versioning that allows detection of collation changes between versions. It is enabled via configure option
--with-icu. The default still uses the operating system's native collation library.
Automatically mark all
DLLEXPORT-ed on Windows (Laurenz Albe)
If third-party code is using
externfunction declarations, they should also add
DLLEXPORTmarkers to those declarations.
Remove SPI functions
SPI_restore_connection()as unnecessary (Tom Lane)
Their functionality now happens automatically. There are now no-op macros by these names so that external modules don't need to be updated immediately, but eventually such calls should be removed.
A side effect of this change is that
SPI_palloc()and allied functions now require an active SPI connection; they do not degenerate to simple
palloc()if there is none. That previous behavior was not very useful and posed risks of unexpected memory leaks.
Allow shared memory to be dynamically allocated (Thomas Munro, Robert Haas)
Add slab-like memory allocator for efficient fixed-size allocations (Tomas Vondra)
Use POSIX semaphores rather than SysV semaphores on Linux and FreeBSD (Tom Lane)
This avoids platform-specific limits on SysV semaphore usage.
Improve support for 64-bit atomics (Andres Freund)
Enable 64-bit atomic operations on ARM64 (Roman Shaposhnik)
Switch to using
clock_gettime(), if available, for duration measurements (Tom Lane)
gettimeofday()is still used if
clock_gettime()is not available.
Add more robust random number generators to be used for cryptographically secure uses (Magnus Hagander, Michael Paquier, Heikki Linnakangas)
If no strong random number generator can be found, configure will fail unless the
--disable-strong-randomoption is used. However, with this option, pgcrypto functions requiring a strong random number generator will be disabled.
WaitLatchOrSocket()to wait for socket connection on Windows (Andres Freund)
tupconvert.cfunctions no longer convert tuples just to embed a different composite-type OID in them (Ashutosh Bapat, Tom Lane)
The majority of callers don't care about the composite-type OID; but if the result tuple is to be used as a composite Datum, steps should be taken to make sure the correct OID is inserted in it.
Remove SCO and Unixware ports (Tom Lane)
Overhaul documentation build process (Alexander Lakhin)
Use XSLT to build the PostgreSQL documentation (Peter Eisentraut)
Previously Jade, DSSSL, and JadeTex were used.
Build HTML documentation using XSLT stylesheets by default (Peter Eisentraut)
E.18.3.12. Additional Modules
Allow file_fdw to read from program output as well as files (Corey Huinker, Adam Gomaa)
In postgres_fdw, push aggregate functions to the remote server, when possible (Jeevan Chalke, Ashutosh Bapat)
This reduces the amount of data that must be passed from the remote server, and offloads aggregate computation from the requesting server.
In postgres_fdw, push joins to the remote server in more cases (David Rowley, Ashutosh Bapat, Etsuro Fujita)
OIDcolumns in postgres_fdw tables (Etsuro Fujita)
OIDcolumns always returned zeros.
This allows enums to be used in exclusion constraints.
Add indexing support to btree_gist for the
UUIDdata type (Paul Jungwirth)
Add amcheck which can check the validity of B-tree indexes (Peter Geoghegan)
Show ignored constants as
?in pg_stat_statements (Lukas Fittl)
Improve cube's handling of zero-dimensional cubes (Tom Lane)
This also improves handling of
Allow pg_buffercache to run with fewer locks (Ivan Kartyshov)
This makes it less disruptive when run on production systems.
Add pgstattuple function
pgstathashindex()to view hash index statistics (Ashutosh Sharma)
GRANTpermissions to control pgstattuple function usage (Stephen Frost)
This allows DBAs to allow non-superusers to run these functions.
Reduce locking when pgstattuple examines hash indexes (Amit Kapila)
Add pageinspect function
page_checksum()to show a page's checksum (Tomas Vondra)
Add pageinspect function
bt_page_items()to print page items from a page image (Tomas Vondra)
Add hash index support to pageinspect (Jesper Pedersen, Ashutosh Sharma)
The following individuals (in alphabetical order) have contributed to this release as patch authors, committers, reviewers, testers, or reporters of issues.
|Aidan Van Dyk|
|Álvaro Hernández Tortosa|
|Andreas Joseph Krogh|
|Ben de Graaff|
|Bruno Wolff III|
|Dagfinn Ilmari Mannsåker|
|Dang Minh Huong|
|Fabrízio de Royes Mello|
|Jeroen van der Ham|
|Karl O. Pinc|
|Kim Rose Carlsen|
|Rafa de la Torre|
|Sven R. Kunze|
|Tom van Tilburg|
|Venkata Balaji Nagothi|
|Yi Wen Wong|
|Zhen Ming Yang|