PostgreSQL (32-bit) 歷史舊版本 Page1

更新時間：2017-11-10
更新細節：

What's new in this version:

- Ensure that INSERT ..ON CONFLICT DO UPDATE checks table permissions and RLS policies in all cases (Dean Rasheed)
- The update path of INSERT ..ON CONFLICT DO UPDATE requires SELECT permission on the columns of the arbiter index, but it failed to check for that in the case of an arbiter specified by constraint nameIn addition, for a table with row level security enabled, it failed to check updated rows against the table's SELECT policies (regardless of how the arbiter index was specified)(CVE-2017-15099)
- Fix crash due to rowtype mismatch in json{b}_populate_recordset() (Michael Paquier, Tom Lane)
- These functions used the result rowtype specified in the FROM ..AS clause without checking that it matched the actual rowtype of the supplied tuple valueIf it didn't, that would usually result in a crash, though disclosure of server memory contents seems possible as well(CVE-2017-15098)
- Fix sample server-start scripts to become $PGUSER before opening $PGLOG (Noah Misch)
- Previously, the postmaster log file was opened while still running as rootThe database owner could therefore mount an attack against another system user by making $PGLOG be a symbolic link to some other file, which would then become corrupted by appending log messages.
- By default, these scripts are not installed anywhereUsers who have made use of them will need to manually recopy them, or apply the same changes to their modified versionsIf the existing $PGLOG file is root-owned, it will need to be removed or renamed out of the way before restarting the server with the corrected script(CVE-2017-12172)
- Fix BRIN index summarization to handle concurrent table extension correctly (Álvaro Herrera)
- Previously, a race condition allowed some table rows to be omitted from the indexIt may be necessary to reindex existing BRIN indexes to recover from past occurrences of this problem.
- Fix possible failures during concurrent updates of a BRIN index (Tom Lane)
- These race conditions could result in errors like “invalid index offnum” or “inconsistent range map”.
- Prevent logical replication from setting non-replicated columns to nulls when replicating an UPDATE (Petr Jelinek)
- Fix logical replication to fire BEFORE ROW DELETE triggers when expected (Masahiko Sawada)
- Previously, that failed to happen unless the table also had a BEFORE ROW UPDATE trigger.
- Fix crash when logical decoding is invoked from a SPI-using function, in particular any function written in a PL language (Tom Lane)
- Ignore CTEs when looking up the target table for INSERT/UPDATE/DELETE, and prevent matching schema-qualified target table names to trigger transition table names (Thomas Munro)
- This restores the pre-v10 behavior for CTEs attached to DML commands.
- Avoid evaluating an aggregate function's argument expression(s) at rows where its FILTER test fails (Tom Lane)
- This restores the pre-v10 (and SQL-standard) behavior.
- Fix incorrect query results when multiple GROUPING SETS columns contain the same simple variable (Tom Lane)
- Fix query-lifespan memory leakage while evaluating a set-returning function in a SELECT's target list (Tom Lane)
- Allow parallel execution of prepared statements with generic plans (Amit Kapila, Kuntal Ghosh)
- Fix incorrect parallelization decisions for nested queries (Amit Kapila, Kuntal Ghosh)
- Fix parallel query handling to not fail when a recently-used role is dropped (Amit Kapila)
- Fix crash in parallel execution of a bitmap scan having a BitmapAnd plan node below a BitmapOr node (Dilip Kumar)
- Fix json_build_array(), json_build_object(), and their jsonb equivalents to handle explicit VARIADIC arguments correctly (Michael Paquier)
- Fix autovacuum's “work item” logic to prevent possible crashes and silent loss of work items (Álvaro Herrera)
- Fix corner-case crashes when columns have been added to the end of a view (Tom Lane)
- Record proper dependencies when a view or rule contains FieldSelect or FieldStore expression nodes (Tom Lane)
- Lack of these dependencies could allow a column or data type DROP to go through when it ought to fail, thereby causing later uses of the view or rule to get errorsThis patch does not do anything to protect existing views/rules, only ones created in the future.
- Correctly detect hashability of range data types (Tom Lane)
- The planner mistakenly assumed that any range type could be hashed for use in hash joins or hash aggregation, but actually it must check whether the range's subtype has hash supportThis does not affect any of the built-in range types, since they're all hashable anyway.
- Correctly ignore RelabelType expression nodes when examining functional-dependency statistics (David Rowley)
- This allows, e.g., extended statistics on varchar columns to be used properly.
- Prevent sharing transition states between ordered-set aggregates (David Rowley)
- This causes a crash with the built-in ordered-set aggregates, and probably with user-written ones as wellv11 and later will include provisions for dealing with such cases safely, but in released branches, just disable the optimization.
- Prevent idle_in_transaction_session_timeout from being ignored when a statement_timeout occurred earlier (Lukas Fittl)
- Fix low-probability loss of NOTIFY messages due to XID wraparound (Marko Tiikkaja, Tom Lane)
- If a session executed no queries, but merely listened for notifications, for more than 2 billion transactions, it started to miss some notifications from concurrently-committing transactions.
- Reduce the frequency of data flush requests during bulk file copies to avoid performance problems on macOS, particularly with its new APFS file system (Tom Lane)
- Allow COPY's FREEZE option to work when the transaction isolation level is REPEATABLE READ or higher (Noah Misch)
- This case was unintentionally broken by a previous bug fix.
- Fix AggGetAggref() to return the correct Aggref nodes to aggregate final functions whose transition calculations have been merged (Tom Lane)
- Fix insufficient schema-qualification in some new queries in pg_dump and psql (Vitaly Burovoy, Tom Lane, Noah Misch)
- Avoid use of @> operator in psql's queries for d (Tom Lane)
- This prevents problems when the parray_gin extension is installed, since that defines a conflicting operator.
- Fix pg_basebackup's matching of tablespace paths to canonicalize both paths before comparing (Michael Paquier)
- This is particularly helpful on Windows.
- Fix libpq to not require user's home directory to exist (Tom Lane)
- In v10, failure to find the home directory while trying to read ~/.pgpass was treated as a hard error, but it should just cause that file to not be foundBoth v10 and previous release branches made the same mistake when reading ~/.pg_service.conf, though this was less obvious since that file is not sought unless a service name is specified.
- In ecpglib, correctly handle backslashes in string literals depending on whether standard_conforming_strings is set (Tsunakawa Takayuki)
- Make ecpglib's Informix-compatibility mode ignore fractional digits in integer input strings, as expected (Gao Zengqi, Michael Meskes)
- Fix missing temp-install prerequisites for check-like Make targets (Noah Misch)
- Some non-default test procedures that are meant to work like make check failed to ensure that the temporary installation was up to date.
- Update time zone data files to tzdata release 2017c for DST law changes in Fiji, Namibia, Northern Cyprus, Sudan, Tonga, and Turks & Caicos Islands, plus historical corrections for Alaska, Apia, Burma, Calcutta, Detroit, Ireland, Namibia, and Pago Pago.
- In the documentation, restore HTML anchors to being upper-case strings (Peter Eisentraut)
- Due to a toolchain change, the 10.0 user manual had lower-case strings for intrapage anchors, thus breaking some external links into our website documentationReturn to our previous convention of using upper-case strings

更新時間：2017-10-06
更新細節：

What's new in this version:

Logical Replication - A publish/subscribe framework for distributing data:
- Logical replication extends the current replication features of PostgreSQL with the ability to send modifications on a per-database and per-table level to different PostgreSQL databases. Users can now fine-tune the data replicated to various database clusters and will have the ability to perform zero-downtime upgrades to future major PostgreSQL versions

Declarative Table Partitioning - Convenience in dividing your data:
- Table partitioning has existed for years in PostgreSQL but required a user to maintain a nontrivial set of rules and triggers for the partitioning to work. PostgreSQL 10 introduces a table partitioning syntax that lets users easily create and maintain range and list partitioned tables. The addition of the partitioning syntax is the first step in a series of planned features to provide a robust partitioning framework within PostgreSQL

Improved Query Parallelism - Quickly conquer your analysis:
- PostgreSQL 10 provides better support for parallelized queries by allowing more parts of the query execution process to be parallelized. Improvements include additional types of data scans that are parallelized as well as optimizations when the data is recombined, such as pre-sorting. These enhancements allow results to be returned more quickly

Quorum Commit for Synchronous Replication - Distribute data with confidence:
- PostgreSQL 10 introduces quorum commit for synchronous replication, which allows for flexibility in how a primary database receives acknowledgement that changes were successfully written to remote replicas. An administrator can now specify that if any number of replicas has acknowledged that a change to the database has been made, then the data can be considered safely written

SCRAM-SHA-256 authentication - Secure your data access:
- The Salted Challenge Response Authentication Mechanism (SCRAM) defined in RFC5802 defines a protocol to improve upon the secure storage and transmission of passwords by providing a framework for strong password negotiation. PostgreSQL 10 introduces the SCRAM-SHA-256 authentication method, defined in RFC7677, to provide better security than the existing MD5-based password authentication method

更新時間：2017-09-01
更新細節：

What's new in this version:

Bug Fixes and Improvements:
This update also fixes a number of bugs reported in the last few weeks. Some of these issues affect only version 9.6, but many affect all supported versions:
- Show foreign tables in information_schema.table_privileges view. This fix applies to new databases, see the release notes for the procedure to apply the fix to an existing database.
- Correctly identify columns that are of a range type or domain type over a composite type or domain type being searched for
- Prevent crash when passing fixed-length pass-by-reference data types to parallel worker processes
- Change ecpg’s parser to allow RETURNING clauses without attached C variables
- Change ecpg’s parser to recognize backslash continuation of C preprocessor command lines
- Improve selection of compiler flags for PL/Perl on Windows

更新時間：2017-08-12
更新細節：

What's new in this version:

Three security vulnerabilities have been closed by this release:
- CVE-2017-7546: Empty password accepted in some authentication methods
- CVE-2017-7547: The "pg_user_mappings" catalog view discloses passwords to users lacking server privileges
- CVE-2017-7548: lo_put() function ignores ACLs

Bug Fixes and Improvements:
This update also fixes a number of bugs reported in the last few months. Some of these issues affect only version 9.6, but many affect all supported versions:
- pg_upgrade: corrected the documentation about the process for upgrading standby servers to ensure the primary and standbys synchronized safely. Also includes a fix to ensure the last WAL record does not have "wal_level = minimum" which would prevent standbys from connecting upon restart
- Fix for issue with a concurrent locking race condition that could cause some of the updates to fail
- Several fixes for low probability data corruption scenarios
- Fix to prevent crash when sorting more than one billion tuples in-memory
- Fix on Windows to retry creating a process if shared memory addresses could not be allocated, typically caused from antivirus software interference
- Fix in libpq to ensure that failed connection attempts using GSS/SASL and SSPI authentication are reset properly
- Fixes for SSL connection handling and logging
- Fix to allow window functions to be used in sub-SELECT statements that are within the arguments of an aggregate function
- Allow parallelism in the query plan when COPY when copying from a query
- Several fixes to ALTER TABLE
- Fix to ensure that ALTER USER ... SET and ALTER ROLE ... SET accepts the same syntax variants
- Fixes for the statistics collector, ensuring statistics requests made just after a postmaster shutdown request will be written to disk
- Fix possible creation of an invalid WAL segment during standby promotion
- Several walsender / walreceiver fixes, particularly around signal handling and shutdowns / restarts
- Several logic decoding fixes, including removing leakage of small subtransactions to disk
- Allow a CHECK constraints to be initially NOT VALID when executing CREATE FOREIGN TABLE
- Fixes to postgres_fdw for applying changes promptly after ALTER SERVER / ALTER USER MAPPING commands and improving ability to escape from an unresponsive server
- Several fixes for pg_dump and pg_restore, including a fix for pg_dump output to stdout on Windows
- Fix pg_basebackup output to stdout on Windows, similar to the fix for pg_dump
- Fix pg_rewind to correctly handle files exceeding 2GB, though files of such size should rarely appear in a data directory
- Several fixes for building PostgreSQL with Microsoft Visual C (MSVC), primarily around sourcing libraries

更新時間：2017-05-12
更新細節：

What's new in this version:

- Restrict visibility of pg_user_mappings.umoptions, to protect passwords stored as user mapping options
- Prevent exposure of statistical information via leaky operators
- Restore libpq's recognition of the PGREQUIRESSL environment variable
- Fix possibly-invalid initial snapshot during logical decoding
- Fix possible corruption of "init forks" of unlogged indexes
- Fix incorrect reconstruction of pg_subtrans entries when a standby server replays a prepared but uncommitted two-phase transaction
- Avoid possible crash in walsender due to failure to initialize a string buffer
- Fix possible crash when rescanning a nearest-neighbor index-only scan on a GiST index
- Prevent delays in postmaster's launching of multiple parallel worker processes
- Fix postmaster's handling of fork() failure for a background worker process
- Fix possible "no relation entry for relid 0" error when planning nested set operations
- Fix assorted minor issues in planning of parallel queries
- Avoid applying "physical targetlist" optimization to custom scans
- Use the correct sub-expression when applying a FOR ALL row-level-security policy
- Ensure parsing of queries in extension scripts sees the results of immediately-preceding DDL
- Skip tablespace privilege checks when ALTER TABLE ... ALTER COLUMN TYPE rebuilds an existing index
- Fix ALTER TABLE ... VALIDATE CONSTRAINT to not recurse to child tables when the constraint is marked NO INHERIT
- Avoid dangling pointer in COPY ... TO when row-level security is active for the source table
- Avoid accessing an already-closed relcache entry in CLUSTER and VACUUM FULL
- Fix VACUUM to account properly for pages that could not be scanned due to conflicting page pins
- Ensure that bulk-tuple-transfer loops within a hash join are interruptible by query cancel requests
- Fix incorrect support for certain box operators in SP-GiST
- Fix integer-overflow problems in interval comparison
- Fix cursor_to_xml() to produce valid output with tableforest = false
- Fix roundoff problems in float8_timestamptz() and make_interval()
- These functions truncated, rather than rounded, when converting a floating-point value to integer microseconds; that could cause unexpectedly off-by-one results.
- Fix pg_get_object_address() to handle members of operator families correctly
- Fix cancelling of pg_stop_backup() when attempting to stop a non-exclusive backup
- If pg_stop_backup() was cancelled while waiting for a non-exclusive backup to end, related state was left inconsistent; a new exclusive backup could not be started, and there were other minor problems.
- Improve performance of pg_timezone_names view
- Reduce memory management overhead for contexts containing many large blocks
- Fix sloppy handling of corner-case errors from lseek() and close()
- Neither of these system calls are likely to fail in typical situations, but if they did, fd.c could get quite confused.
- Fix incorrect check for whether postmaster is running as a Windows service
- This could result in attempting to write to the event log when that isn't accessible, so that no logging happens at all.
- Fix ecpg to support COMMIT PREPARED and ROLLBACK PREPARED
- Fix a double-free error when processing dollar-quoted string literals in ecpg
- Fix pgbench to handle the combination of --connect and --rate options correctly
- Fix pgbench to honor the long-form option spelling --builtin, as per its documentation
- Fix pg_dump/pg_restore to correctly handle privileges for the public schema when using --clean option
- Other schemas start out with no privileges granted, but public does not; this requires special-case treatment when it is dropped and restored due to the --clean option.
- In pg_dump, fix incorrect schema and owner marking for comments and security labels of some types of database objects
- In simple cases this caused no ill effects; but for example, a schema-selective restore might omit comments it should include, because they were not marked as belonging to the schema of their associated object.
- Fix typo in pg_dump's query for initial privileges of a procedural language
- This resulted in pg_dump always believing that the language had no initial privileges. Since that's true for most procedural languages, ill effects from this bug are probably rare.
- Avoid emitting an invalid list file in pg_restore -l when SQL object names contain newlines
- Replace newlines by spaces, which is sufficient to make the output valid for pg_restore -L's purposes
- Fix pg_upgrade to transfer comments and security labels attached to "large objects" (blobs)
- Previously, blobs were correctly transferred to the new database, but any comments or security labels attached to them were lost
- Improve error handling in contrib/adminpack's pg_file_write() function
- Notably, it failed to detect errors reported by fclose().
- In contrib/dblink, avoid leaking the previous unnamed connection when establishing a new unnamed connection
- Fix contrib/pg_trgm's extraction of trigrams from regular expressions
- In some cases it would produce a broken data structure that could never match anything, leading to GIN or GiST indexscans that use a trigram index not finding any matches to the regular expression.
- In contrib/postgres_fdw, allow join conditions that contain shippable extension-provided functions to be pushed to the remote server
- Support Tcl 8.6 in MSVC builds
- Sync our copy of the timezone library with IANA release tzcode2017b
- This fixes a bug affecting some DST transitions in January 2038.
- Update time zone data files to tzdata release 2017b for DST law changes in Chile, Haiti, and Mongolia, plus historical corrections for Ecuador, Kazakhstan, Liberia, and Spain. Switch to numeric abbreviations for numerous time zones in South America, the Pacific and Indian oceans, and some Asian and Middle Eastern countries.
- The IANA time zone database previously provided textual abbreviations for all time zones, sometimes making up abbreviations that have little or no currency among the local population. They are in process of reversing that policy in favor of using numeric UTC offsets in zones where there is no evidence of real-world use of an English abbreviation. At least for the time being, PostgreSQL will continue to accept such removed abbreviations for timestamp input. But they will not be shown in the pg_timezone_names view nor used for output.
- Use correct daylight-savings rules for POSIX-style time zone names in MSVC builds
- The Microsoft MSVC build scripts neglected to install the posixrules file in the timezone directory tree. This resulted in the timezone code falling back to its built-in rule about what DST behavior to assume for a POSIX-style time zone name. For historical reasons that still corresponds to the DST rules the USA was using before 2007 (i.e., change on first Sunday in April and last Sunday in October). With this fix, a POSIX-style zone name will use the current and historical DST transition dates of the US/Eastern zone. If you don't want that, remove the posixrules file, or replace it with a copy of some other zone file (see Section 8.5.3). Note that due to caching, you may need to restart the server to get such changes to take effect.

更新時間：2017-02-10
更新細節：

What's new in this version:

BUILD CORRUPTION WITH CREATE INDEX CONCURRENTLY:
- There existed a race condition if CREATE INDEX CONCURRENTLY was called on a column that had not been indexed before, then rows that were updated by transactions running at the same time as the CREATE INDEX CONCURRENTLY command could have been indexed incorrectly.
- If you suspect this may have happened, the most reliable solution is to rebuild affected indexes after installing this update
- This issue is present in the 9.2, 9.3, 9.4, 9.5, and 9.6 series of PostgreSQL

FIXES FOR VISIBILITY AND WRITE-AHEAD-LOG STABILITY:
- These release contains several fixes to improve the stability of visible data and WAL logging that we wish to highlight here.
- Prior to this release, data could be prematurely pruned by a vacuum operation when a special snapshot used for catalog scans was presently available. Specifically, the vacuum operation would not be aware of the oldest xmin for this special snapshot. The error would surface with a message such as: "cache lookup failed for relation 1255"
- This release ensures that vacuum operations will account for the catalog scan snapshots.

Additionally, there are several fixes to improved the stability of write-ahead-logging, including:
- A fix for BRIN index WAL logging where a replay could make a portion of the BRIN index useless and require recomputing
- A fix for an unlogged table where a WAL-log would be created under the "wal_level = minimal" setting, and upon replay after crash, the table would not appear to be properly reset
- A fix in the WAL page header validation when re-reading segments that fixes the error of "out-of-sequence TLI" that could be reported during recovery
- Theses issues are present in the 9.6 series of PostgreSQL releases and may also be present in the 9.2, 9.3, 9.4, and 9.5 series.

BUG FIXES AND IMPROVEMENTS:
- This update also fixes a number of bugs reported in the last few months. Some of these issues affect only the 9.6 series, but many affect all supported versions.

There are more than 75 fixes provided in this release, including:
- Several fixes for operating in hot standby mode
- Disallow setting the num_sync field to zero in synchronous_standby_names
- Don't count background worker processes against a user's connection limit
- Fix check for when an extension member object can be dropped
- Fix tracking of initial privileges for extension member objects so that it works correctly with ALTER EXTENSION ... ADD/DROP
- Several vacuum and autovacuum fixes
- Fix CREATE OR REPLACE VIEW to update the view query before attempting to apply the new view options
- Make sure ALTER TABLE preserves index tablespace assignments when rebuilding indexes
- Several fixes to the query planner, including fixes for foreign tables and CTEs
- Several fixes around the full-text search feature to improve accuracy and performance of the search
- Several fixes and performance improvements in several array functions
- Several fixes around the interaction of foreign-key constraints with trigger functions around specific ALTER TABLE operations
- Remove optimizations for date/time data types that returned incorrect data
- Fix incorrect use of view reloptions as regular table reloptions
- Fix incorrect "target lists can have at most N entries" complaint when using ON CONFLICT with wide tables
- Fix spurious "query provides a value for a dropped column" errors during INSERT or UPDATE on a table with a dropped column
- Prevent multicolumn expansion of foo.* in an UPDATE source expression
- Ensure that column typmods are determined accurately for multi-row VALUES constructs
- Several fixes for the psql command-line tool
- Prevent multiple calls of pg_start_backup() and pg_stop_backup() from running concurrently
- Several fixes for pg_dump, pg_restore, and pg_basebackup, including a possible pg_basebackup failure on standby server when including WAL files
- Several fixes for parallel workers and plans for parallel queries including fixing a crash if the number of workers available to a parallel query decreases during a rescan
- Several fixes to PL/pgSQL, PL/Python, and PL/Tcl
- Several fixes for contrib modules
- Allow DOS-style line endings in ~/.pgpass files, even on Unix

更新時間：2016-10-27
更新細節：

What's new in this version:

- Fix WAL-logging of truncation of relation free space maps and visibility maps (Pavan Deolasee, Heikki Linnakangas)
- It was possible for these files to not be correctly restored during crash recovery, or to be written incorrectly on a standby server. Bogus entries in a free space map could lead to attempts to access pages that have been truncated away from the relation itself, typically producing errors like "could not read block XXX: read only 0 of 8192 bytes". Checksum failures in the visibility map are also possible, if checksumming is enabled.
- Procedures for determining whether there is a problem and repairing it if so are discussed at https://wiki.postgresql.org/wiki/Free_Space_Map_Problems.
- Fix possible data corruption when pg_upgrade rewrites a relation visibility map into 9.6 format (Tom Lane)
- On big-endian machines, bytes of the new visibility map were written in the wrong order, leading to a completely incorrect map. On Windows, the old map was read using text mode, leading to incorrect results if the map happened to contain consecutive bytes that matched a carriage return/line feed sequence. The latter error would almost always lead to a pg_upgrade failure due to the map file appearing to be the wrong length.
- If you are using a big-endian machine (many non-Intel architectures are big-endian) and have used pg_upgrade to upgrade from a pre-9.6 release, you should assume that all visibility maps are incorrect and need to be regenerated. It is sufficient to truncate each relation's visibility map with contrib/pg_visibility's pg_truncate_visibility_map() function. For more information see https://wiki.postgresql.org/wiki/Visibility_Map_Problems.
- Don't throw serialization errors for self-conflicting insertions in INSERT ... ON CONFLICT (Thomas Munro, Peter Geoghegan)
- Fix use-after-free hazard in execution of aggregate functions using DISTINCT (Peter Geoghegan)
- This could lead to a crash or incorrect query results.
- Fix incorrect handling of polymorphic aggregates used as window functions (Tom Lane)
- The aggregate's transition function was told that its first argument and result were of the aggregate's output type, rather than the state type. This led to errors or crashes with polymorphic transition functions.
- Fix COPY with a column name list from a table that has row-level security enabled (Adam Brightwell)
- Fix EXPLAIN to emit valid XML when track_io_timing is on (Markus Winand)
- Previously the XML output-format option produced syntactically invalid tags such as <I/O-Read-Time>. That is now rendered as <I-O-Read-Time>.
- Fix statistics update for TRUNCATE in a prepared transaction (Stas Kelvich)
- Fix bugs in merging inherited CHECK constraints while creating or altering a table (Tom Lane, Amit Langote)
- Allow identical CHECK constraints to be added to a parent and child table in either order. Prevent merging of a valid constraint from the parent table with a NOT VALID constraint on the child. Likewise, prevent merging of a NO INHERIT child constraint with an inherited constraint.
- Show a sensible value in pg_settings.unit for min_wal_size and max_wal_size (Tom Lane)
- Fix replacement of array elements in jsonb_set() (Tom Lane)
- If the target is an existing JSON array element, it got deleted instead of being replaced with a new value.
- Avoid very-low-probability data corruption due to testing tuple visibility without holding buffer lock (Thomas Munro, Peter Geoghegan, Tom Lane)
- Preserve commit timestamps across server restart (Julien Rouhaud, Craig Ringer)
- With track_commit_timestamp turned on, old commit timestamps became inaccessible after a clean server restart.
- Fix logical WAL decoding to work properly when a subtransaction's WAL output is large enough to spill to disk (Andres Freund)
- Fix dangling-pointer problem in logical WAL decoding (Stas Kelvich)
- Round shared-memory allocation request to a multiple of the actual huge page size when attempting to use huge pages on Linux (Tom Lane)
- This avoids possible failures during munmap() on systems with atypical default huge page sizes. Except in crash-recovery cases, there were no ill effects other than a log message.
- Don't try to share SSL contexts across multiple connections in libpq (Heikki Linnakangas)
- This led to assorted corner-case bugs, particularly when trying to use different SSL parameters for different connections.
- Avoid corner-case memory leak in libpq (Tom Lane)
- The reported problem involved leaking an error report during PQreset(), but there might be related cases.
- In pg_upgrade, check library loadability in name order (Tom Lane)
- This is a workaround to deal with cross-extension dependencies from language transform modules to their base language and data type modules.
- Fix pg_upgrade to work correctly for extensions containing index access methods (Tom Lane)
- To allow this, the server has been extended to support ALTER EXTENSION ADD/DROP ACCESS METHOD. That functionality should have been included in the original patch to support dynamic creation of access methods, but it was overlooked.
- Improve error reporting in pg_upgrade's file copying/linking/rewriting steps (Tom Lane, Álvaro Herrera)
- Fix pg_dump to work against pre-7.4 servers (Amit Langote, Tom Lane)
- Disallow specifying both --source-server and --source-target options to pg_rewind (Michael Banck)
- Make pg_rewind turn off synchronous_commit in its session on the source server (Michael Banck, Michael Paquier)
- This allows pg_rewind to work even when the source server is using synchronous replication that is not working for some reason.
- In pg_xlogdump, retry opening new WAL segments when using --follow option (Magnus Hagander)
- This allows for a possible delay in the server's creation of the next segment.
- Fix contrib/pg_visibility to report the correct TID for a corrupt tuple that has been the subject of a rolled-back update (Tom Lane)
- Fix makefile dependencies so that parallel make of PL/Python by itself will succeed reliably (Pavel Raiskup)
- Update time zone data files to tzdata release 2016h for DST law changes in Palestine and Turkey, plus historical corrections for Turkey and some regions of Russia. Switch to numeric abbreviations for some time zones in Antarctica, the former Soviet Union, and Sri Lanka.
- The IANA time zone database previously provided textual abbreviations for all time zones, sometimes making up abbreviations that have little or no currency among the local population. They are in process of reversing that policy in favor of using numeric UTC offsets in zones where there is no evidence of real-world use of an English abbreviation. At least for the time being, PostgreSQL will continue to accept such removed abbreviations for timestamp input. But they will not be shown in the pg_timezone_names view nor used for output.
- In this update, AMT is no longer shown as being in use to mean Armenia Time. Therefore, we have changed the Default abbreviation set to interpret it as Amazon Time, thus UTC-4 not UTC+4.

更新時間：2016-09-30
更新細節：

What's new in this version:

- This release will allow users to both scale up and scale out high performance database workloads. New features include parallel query, synchronous replication improvements, phrase search, and improvements to performance and usability, as well as many more features.

Scale Up with Parallel Query:
- Version 9.6 adds support for parallelizing some query operations, enabling utilization of several or all of the cores on a server to return query results faster. This release includes parallel sequential (table) scan, aggregation, and joins. Depending on details and available cores, parallelism can speed up big data queries by as much as 32 times faster.
- "I migrated our entire genomics data platform - all 25 billion legacy MySQL rows of it - to a single Postgres database, leveraging the row compression abilities of the JSONB datatype, and the excellent GIN, BRIN, and B-tree indexing modes. Now with version 9.6, I expect to harness the parallel query functionality to allow even greater scalability for queries against our rather large tables," said Mike Sofen, Chief Database Architect, Synthetic Genomics.

Scale Out with Synchronous Replication and postgres_fdw:
- Two new options have been added to PostgreSQL's synchronous replication feature which allow it to be used to maintain consistent reads across database clusters. First, it now allows configuring groups of synchronous replicas. Second, the "remote_apply" mode creates a more consistent view of data across multiple nodes. These features support using built-in replication to maintain a set of "identical" nodes for load-balancing read workloads.
- The PostgreSQL-to-PostgreSQL data federation driver, postgres_fdw, has new capabilities to execute work on remote servers. By "pushing down" sorts, joins, and batch data updates, users can distribute workload across multiple PostgreSQL servers. These features should soon be added to other FDW drivers.
- "With the capabilities of remote JOIN, UPDATE and DELETE, Foreign Data Wrappers are now a complete solution for sharing data between other databases and PostgreSQL. For example, PostgreSQL can be used to handle data input going to two or more different kinds of databases," said Julyanto Sutandang, Director of Business Solutions at Equnix.

Better Text Search with Phrases:
- PostgreSQL's full text search feature now supports "phrase search." This lets users search for exact phrases, or for words within a specified proximity to each other, using fast GIN indexes. Combined with new features for fine-tuning text search options, PostgreSQL is the superior option for "hybrid search" which puts together relational, JSON, and full text searching.

Smoother, Faster, and Easier to Use:
- Thanks to feedback and testing by PostgreSQL users with high-volume production databases, the project has been able to improve many aspects of performance and usability in this release. Replication, aggregation, indexing, sorting, and stored procedures have all been made more efficient, and PostgreSQL now makes better use of resources with recent Linux kernels. Administration overhead for large tables and complex workloads was also reduced, especially through improvements to VACUUM.

Other Features:
- New system views and functions: pg_stat_wal_receiver, pg_visibility, pg_config, pg_blocking_pids, pg_notification_queue_usage
- Command progress reporting support
- Cascade support for installing extensions
- pg_basebackup concurrency and replication slot support
- Wait Event support
- View editing and crosstabs in psql
- User-defined expiration for old snapshots
- Index-only scans for partial indexes

更新時間：2016-08-11
更新細節：

What's new in this version:

Two security holes have been closed by this release:
- CVE-2016-5423: certain nested CASE expressions can cause the server to crash.
- CVE-2016-5424: database and role names with embedded special characters can allow code injection during administrative operations like pg_dumpall. The fix for the second issue also adds an option, -reuse-previous, to psql's connect command. pg_dumpall will also refuse to handle database and role names containing line breaks after the update. For more information on these issues and how they affect backwards-compatibility, see the Release Notes.

Bug Fixes and Improvements:
- This update also fixes a number of bugs reported in the last few months. Some of these issues affect only version 9.5, but many affect all supported versions
- Fix misbehaviors of IS NULL/IS NOT NULL with composite values
- Fix three areas where INSERT ... ON CONFLICT failed to work properly with other SQL features
- Make INET and CIDR data types properly reject bad IPv6 values
- Prevent crash in "point ## lseg" operator for NaN input
- Avoid possible crash in pg_get_expr()
- Fix several one-byte buffer over-reads in to_number()
- Don't needlessly plan query if WITH NO DATA is specified
- Avoid crash-unsafe state in expensive heap_update() paths
- Fix hint bit update during WAL replay of row locking operations
- Avoid unnecessary "could not serialize access" with FOR KEY SHARE
- Avoid crash in postgres -C when the specified variable is a null string
- Fix two issues with logical decoding and subtransactions
- Ensure that backends see up-to-date statistics for shared catalogs
- Prevent possible failure when vacuuming multixact IDs in an upgraded database
- When a manual ANALYZE specifies columns, don't reset changes_since_analyze
- Fix ANALYZE's overestimation of n_distinct for columns with nulls
- Fix bug in b-tree mark/restore processing
- Fix building of large (bigger than shared_buffers) hash indexes
- Prevent infinite loop in GiST index build with NaN values
- Fix possible crash during a nearest-neighbor indexscan
- Fix "PANIC: failed to add BRIN tuple" error
- Prevent possible crash during background worker shutdown
- Many fixes for issues in parallel pg_dump and pg_restore
- Make pg_basebackup accept -Z 0 as no compression
- Make regression tests safe for Danish and Welsh locales
- The libpq client library has also been updated to support future two-part PostgreSQL version numbers. This update also contains tzdata release 2016f, with updates for Kemerovo, Novosibirsk, Azerbaijan, Belarus, and Morocco

更新時間：2016-05-12
更新細節：

What's new in this version:

- Clear the OpenSSL error queue before OpenSSL calls, rather than assuming it's clear already; and make sure we leave it clear afterwards (Peter Geoghegan, Dave Vitek, Peter Eisentraut)
- This change prevents 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. Failures have been reported specifically when a client application uses SSL connections in libpq concurrently with SSL connections using the PHP, Python, or Ruby wrappers for OpenSSL. It's possible for similar problems to arise within the server as well, if an extension module establishes an outgoing SSL connection.
- Fix "failed to build any N-way joins" planner error with a full join enclosed in the right-hand side of a left join (Tom Lane)
- Fix incorrect handling of equivalence-class tests in multilevel nestloop plans (Tom Lane)
- Given a three-or-more-way equivalence class of variables, such as X.X = Y.Y = Z.Z, it was possible for the planner to omit some of the tests needed to enforce that all the variables are actually equal, leading to join rows being output that didn't satisfy the WHERE clauses. For various reasons, erroneous plans were seldom selected in practice, so that this bug has gone undetected for a long time.
- Fix corner-case parser failures occurring when operator_precedence_warning is turned on (Tom Lane)
- An example is that SELECT (ARRAY[])::text[] gave an error, though it worked without the parentheses.
- Fix query-lifespan memory leak in GIN index scans (Julien Rouhaud)
- Fix query-lifespan memory leak and potential index corruption hazard in GIN index insertion (Tom Lane)
- The memory leak would typically not amount to much in simple queries, but it could be very substantial during a large GIN index build with high maintenance_work_mem.
- Fix possible misbehavior of TH, th, and Y,YYY format codes in to_timestamp() (Tom Lane)
- These could advance off the end of the input string, causing subsequent format codes to read garbage.
- Fix dumping of rules and views in which the array argument of a value operator ANY (array) construct is a sub-SELECT (Tom Lane)
- Disallow newlines in ALTER SYSTEM parameter values (Tom Lane)
- The configuration-file parser doesn't support embedded newlines in string literals, so we mustn't allow them in values to be inserted by ALTER SYSTEM.
- Fix ALTER TABLE ... REPLICA IDENTITY USING INDEX to work properly if an index on OID is selected (David Rowley)
- Avoid possible misbehavior after failing to remove a tablespace symlink (Tom Lane)
- Fix crash in logical decoding on alignment-picky platforms (Tom Lane, Andres Freund)
- The failure occurred only with a transaction large enough to spill to disk and a primary-key change within that transaction.
- Avoid repeated requests for feedback from receiver while shutting down walsender (Nick Cleaton)
- Make pg_regress use a startup timeout from the PGCTLTIMEOUT environment variable, if that's set (Tom Lane)
- This is for consistency with a behavior recently added to pg_ctl; it eases automated testing on slow machines.
- Fix pg_upgrade to correctly restore extension membership for operator families containing only one operator class (Tom Lane)
- In such a case, the operator family was restored into the new database, but it was no longer marked as part of the extension. This had no immediate ill effects, but would cause later pg_dump runs to emit output that would cause (harmless) errors on restore.
- Fix pg_upgrade to not fail when new-cluster TOAST rules differ from old (Tom Lane)
- pg_upgrade had special-case code to handle the situation where the new PostgreSQL version thinks that a table should have a TOAST table while the old version did not. That code was broken, so remove it, and instead do nothing in such cases; there seems no reason to believe that we can't get along fine without a TOAST table if that was okay according to the old version's rules.
- Fix atomic operations for PPC when using IBM's XLC compiler (Noah Misch)
- Reduce the number of SysV semaphores used by a build configured with --disable-spinlocks (Tom Lane)
- Rename internal function strtoi() to strtoint() to avoid conflict with a NetBSD library function (Thomas Munro)
- Fix reporting of errors from bind() and listen() system calls on Windows (Tom Lane)
- Reduce verbosity of compiler output when building with Microsoft Visual Studio (Christian Ullrich)
- Support building with Visual Studio 2015 (Michael Paquier, Petr Jelínek)
- Fix putenv() to work properly with Visual Studio 2013 (Michael Paquier)
- Avoid possibly-unsafe use of Windows' FormatMessage() function (Christian Ullrich)
- Use the FORMAT_MESSAGE_IGNORE_INSERTS flag where appropriate. No live bug is known to exist here, but it seems like a good idea to be careful.
- Update time zone data files to tzdata release 2016d for DST law changes in Russia and Venezuela. There are new zone names Europe/Kirov and Asia/Tomsk to reflect the fact that these regions now have different time zone histories from adjacent regions.