2009-09-09 This release contains a variety of fixes from 8.3.7. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, if you have any hash indexes on interval columns, you must REINDEX them after updating to 8.3.8. Also, if you are upgrading from a version earlier than 8.3.5, see the release notes for 8.3.5. Fix Windows shared-memory allocation code (Tsutomu Yamada, Magnus) This bug led to the often-reported could not reattach to shared memory error message. Force WAL segment switch during pg_start_backup() (Heikki) This avoids corner cases that could render a base backup unusable. Disallow RESET ROLE and RESET SESSION AUTHORIZATION inside security-definer functions (Tom, Heikki) This covers a case that was missed in the previous patch that disallowed SET ROLE and SET SESSION AUTHORIZATION inside security-definer functions. (See CVE-2007-6600) Make LOAD of an already-loaded loadable module into a no-op (Tom) Formerly, LOAD would attempt to unload and re-load the module, but this is unsafe and not all that useful. Disallow empty passwords during LDAP authentication (Magnus) Fix handling of sub-SELECTs appearing in the arguments of an outer-level aggregate function (Tom) Fix bugs associated with fetching a whole-row value from the output of a Sort or Materialize plan node (Tom) Prevent synchronize_seqscans from changing the results of scrollable and WITH HOLD cursors (Tom) Revert planner change that disabled partial-index and constraint exclusion optimizations when there were more than 100 clauses in an AND or OR list (Tom) Fix hash calculation for data type interval (Tom) This corrects wrong results for hash joins on interval values. It also changes the contents of hash indexes on interval columns. If you have any such indexes, you must REINDEX them after updating. Treat to_char(..., 'TH') as an uppercase ordinal suffix with 'HH'/'HH12' (Heikki) It was previously handled as 'th' (lowercase). Fix overflow for INTERVAL 'x ms' when x is more than 2 million and integer datetimes are in use (Alex Hunsaker) Fix calculation of distance between a point and a line segment (Tom) This led to incorrect results from a number of geometric operators. Fix money data type to work in locales where currency amounts have no fractional digits, e.g. Japan (Itagaki Takahiro) Fix LIKE for case where pattern contains %_ (Tom) Properly round datetime input like 00:12:57.9999999999999999999999999999 (Tom) Fix memory leaks in XML operations (Tom) Fix poor choice of page split point in GiST R-tree operator classes (Teodor) Ensure that a fast shutdown request will forcibly terminate open sessions, even if a smart shutdown was already in progress (Fujii Masao) Avoid performance degradation in bulk inserts into GIN indexes when the input values are (nearly) in sorted order (Tom) Correctly enforce NOT NULL domain constraints in some contexts in PL/pgSQL (Tom) Fix portability issues in plperl initialization (Andrew Dunstan) Fix pg_ctl to not go into an infinite loop if postgresql.conf is empty (Jeff Davis) Improve pg_dump's efficiency when there are many large objects (Tamas Vincze) Use SIGUSR1, not SIGQUIT, as the failover signal for pg_standby (Heikki) Make pg_standby's maxretries option behave as documented (Fujii Masao) Make contrib/hstore throw an error when a key or value is too long to fit in its data structure, rather than silently truncating it (Andrew Gierth) Fix contrib/xml2's xslt_process() to properly handle the maximum number of parameters (twenty) (Tom) Improve robustness of libpq's code to recover from errors during COPY FROM STDIN (Tom) Avoid including conflicting readline and editline header files when both libraries are installed (Zdenek Kotala) Update time zone data files to tzdata release 2009l for DST law changes in Bangladesh, Egypt, Jordan, Pakistan, Argentina/San_Luis, Cuba, Jordan (historical correction only), Mauritius, Morocco, Palestine, Syria, Tunisia. 2009-03-16 This release contains a variety of fixes from 8.3.6. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, if you are upgrading from a version earlier than 8.3.5, see the release notes for 8.3.5. Prevent error recursion crashes when encoding conversion fails (Tom) This change extends fixes made in the last two minor releases for related failure scenarios. The previous fixes were narrowly tailored for the original problem reports, but we have now recognized that any error thrown by an encoding conversion function could potentially lead to infinite recursion while trying to report the error. The solution therefore is to disable translation and encoding conversion and report the plain-ASCII form of any error message, if we find we have gotten into a recursive error reporting situation. (CVE-2009-0922) Disallow CREATE CONVERSION with the wrong encodings for the specified conversion function (Heikki) This prevents one possible scenario for encoding conversion failure. The previous change is a backstop to guard against other kinds of failures in the same area. Fix xpath() to not modify the path expression unless necessary, and to make a saner attempt at it when necessary (Andrew) The SQL standard suggests that xpath should work on data that is a document fragment, but libxml doesn't support that, and indeed it's not clear that this is sensible according to the XPath standard. xpath attempted to work around this mismatch by modifying both the data and the path expression, but the modification was buggy and could cause valid searches to fail. Now, xpath checks whether the data is in fact a well-formed document, and if so invokes libxml with no change to the data or path expression. Otherwise, a different modification method that is somewhat less likely to fail is used. The new modification method is still not 100% satisfactory, and it seems likely that no real solution is possible. This patch should therefore be viewed as a band-aid to keep from breaking existing applications unnecessarily. It is likely that PostgreSQL 8.4 will simply reject use of xpath on data that is not a well-formed document. Fix core dump when to_char() is given format codes that are inappropriate for the type of the data argument (Tom) Fix possible failure in text search when C locale is used with a multi-byte encoding (Teodor) Crashes were possible on platforms where wchar_t is narrower than int; Windows in particular. Fix extreme inefficiency in text search parser's handling of an email-like string containing multiple @ characters (Heikki) Fix planner problem with sub-SELECT in the output list of a larger subquery (Tom) The known symptom of this bug is a failed to locate grouping columns error that is dependent on the datatype involved; but there could be other issues as well. Fix decompilation of CASE WHEN with an implicit coercion (Tom) This mistake could lead to Assert failures in an Assert-enabled build, or an unexpected CASE WHEN clause error message in other cases, when trying to examine or dump a view. Fix possible misassignment of the owner of a TOAST table's rowtype (Tom) If CLUSTER or a rewriting variant of ALTER TABLE were executed by someone other than the table owner, the pg_type entry for the table's TOAST table would end up marked as owned by that someone. This caused no immediate problems, since the permissions on the TOAST rowtype aren't examined by any ordinary database operation. However, it could lead to unexpected failures if one later tried to drop the role that issued the command (in 8.1 or 8.2), or owner of data type appears to be invalid warnings from pg_dump after having done so (in 8.3). Change UNLISTEN to exit quickly if the current session has never executed any LISTEN command (Tom) Most of the time this is not a particularly useful optimization, but since DISCARD ALL invokes UNLISTEN, the previous coding caused a substantial performance problem for applications that made heavy use of DISCARD ALL. Fix PL/pgSQL to not treat INTO after INSERT as an INTO-variables clause anywhere in the string, not only at the start; in particular, don't fail for INSERT INTO within CREATE RULE (Tom) Clean up PL/pgSQL error status variables fully at block exit (Ashesh Vashi and Dave Page) This is not a problem for PL/pgSQL itself, but the omission could cause the PL/pgSQL Debugger to crash while examining the state of a function. Retry failed calls to CallNamedPipe() on Windows (Steve Marshall, Magnus) It appears that this function can sometimes fail transiently; we previously treated any failure as a hard error, which could confuse LISTEN/NOTIFY as well as other operations. Add MUST (Mauritius Island Summer Time) to the default list of known timezone abbreviations (Xavier Bugaud) 2009-02-02 This release contains a variety of fixes from 8.3.5. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, if you are upgrading from a version earlier than 8.3.5, see the release notes for 8.3.5. Make DISCARD ALL release advisory locks, in addition to everything it already did (Tom) This was decided to be the most appropriate behavior. This could affect existing applications, however. Fix whole-index GiST scans to work correctly (Teodor) This error could cause rows to be lost if a table is clustered on a GiST index. Fix crash of xmlconcat(NULL) (Peter) Fix possible crash in ispell dictionary if high-bit-set characters are used as flags (Teodor) This is known to be done by one widely available Norwegian dictionary, and the same condition may exist in others. Fix misordering of pg_dump output for composite types (Tom) The most likely problem was for user-defined operator classes to be dumped after indexes or views that needed them. Improve handling of URLs in headline() function (Teodor) Improve handling of overlength headlines in headline() function (Teodor) Prevent possible Assert failure or misconversion if an encoding conversion is created with the wrong conversion function for the specified pair of encodings (Tom, Heikki) Fix possible Assert failure if a statement executed in PL/pgSQL is rewritten into another kind of statement, for example if an INSERT is rewritten into an UPDATE (Heikki) Ensure that a snapshot is available to datatype input functions (Tom) This primarily affects domains that are declared with CHECK constraints involving user-defined stable or immutable functions. Such functions typically fail if no snapshot has been set. Make it safer for SPI-using functions to be used within datatype I/O; in particular, to be used in domain check constraints (Tom) Avoid unnecessary locking of small tables in VACUUM (Heikki) Fix a problem that sometimes kept ALTER TABLE ENABLE/DISABLE RULE from being recognized by active sessions (Tom) Fix a problem that made UPDATE RETURNING tableoid return zero instead of the correct OID (Tom) Allow functions declared as taking ANYARRAY to work on the pg_statistic columns of that type (Tom) This used to work, but was unintentionally broken in 8.3. Fix planner misestimation of selectivity when transitive equality is applied to an outer-join clause (Tom) This could result in bad plans for queries like ... from a left join b on a.a1 = b.b1 where a.a1 = 42 ... Improve optimizer's handling of long IN lists (Tom) This change avoids wasting large amounts of time on such lists when constraint exclusion is enabled. Prevent synchronous scan during GIN index build (Tom) Because GIN is optimized for inserting tuples in increasing TID order, choosing to use a synchronous scan could slow the build by a factor of three or more. Ensure that the contents of a holdable cursor don't depend on the contents of TOAST tables (Tom) Previously, large field values in a cursor result might be represented as TOAST pointers, which would fail if the referenced table got dropped before the cursor is read, or if the large value is deleted and then vacuumed away. This cannot happen with an ordinary cursor, but it could with a cursor that is held past its creating transaction. Fix memory leak when a set-returning function is terminated without reading its whole result (Tom) Fix encoding conversion problems in XML functions when the database encoding isn't UTF-8 (Tom) Fix contrib/dblink's dblink_get_result(text,bool) function (Joe) Fix possible garbage output from contrib/sslinfo functions (Tom) Fix incorrect behavior of contrib/tsearch2 compatibility trigger when it's fired more than once in a command (Teodor) Fix possible mis-signaling in autovacuum (Heikki) Support running as a service on Windows 7 beta (Dave and Magnus) Fix ecpg's handling of varchar structs (Michael) Fix configure script to properly report failure when unable to obtain linkage information for PL/Perl (Andrew) Make all documentation reference pgsql-bugs and/or pgsql-hackers as appropriate, instead of the now-decommissioned pgsql-ports and pgsql-patches mailing lists (Tom) Update time zone data files to tzdata release 2009a (for Kathmandu and historical DST corrections in Switzerland, Cuba) 2008-11-03 This release contains a variety of fixes from 8.3.4. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, if you are upgrading from a version earlier than 8.3.1, see the release notes for 8.3.1. Also, if you were running a previous 8.3.X release, it is recommended to REINDEX all GiST indexes after the upgrade. Fix GiST index corruption due to marking the wrong index entry dead after a deletion (Teodor) This would result in index searches failing to find rows they should have found. Corrupted indexes can be fixed with REINDEX. Fix backend crash when the client encoding cannot represent a localized error message (Tom) We have addressed similar issues before, but it would still fail if the character has no equivalent message itself couldn't be converted. The fix is to disable localization and send the plain ASCII error message when we detect such a situation. Fix possible crash in bytea-to-XML mapping (Michael McMaster) Fix possible crash when deeply nested functions are invoked from a trigger (Tom) Improve optimization of expression IN (expression-list) queries (Tom, per an idea from Robert Haas) Cases in which there are query variables on the right-hand side had been handled less efficiently in 8.2.x and 8.3.x than in prior versions. The fix restores 8.1 behavior for such cases. Fix mis-expansion of rule queries when a sub-SELECT appears in a function call in FROM, a multi-row VALUES list, or a RETURNING list (Tom) The usual symptom of this problem is an unrecognized node type error. Fix Assert failure during rescan of an IS NULL search of a GiST index (Teodor) Fix memory leak during rescan of a hashed aggregation plan (Neil) Ensure an error is reported when a newly-defined PL/pgSQL trigger function is invoked as a normal function (Tom) Force a checkpoint before CREATE DATABASE starts to copy files (Heikki) This prevents a possible failure if files had recently been deleted in the source database. Prevent possible collision of relfilenode numbers when moving a table to another tablespace with ALTER SET TABLESPACE (Heikki) The command tried to re-use the existing filename, instead of picking one that is known unused in the destination directory. Fix incorrect text search headline generation when single query item matches first word of text (Sushant Sinha) Fix improper display of fractional seconds in interval values when using a non-ISO datestyle in an --enable-integer-datetimes build (Ron Mayer) Make ILIKE compare characters case-insensitively even when they're escaped (Andrew) Ensure DISCARD is handled properly by statement logging (Tom) Fix incorrect logging of last-completed-transaction time during PITR recovery (Tom) Ensure SPI_getvalue and SPI_getbinval behave correctly when the passed tuple and tuple descriptor have different numbers of columns (Tom) This situation is normal when a table has had columns added or removed, but these two functions didn't handle it properly. The only likely consequence is an incorrect error indication. Mark SessionReplicationRole as PGDLLIMPORT so it can be used by Slony on Windows (Magnus) Fix small memory leak when using libpq's gsslib parameter (Magnus) The space used by the parameter string was not freed at connection close. Ensure libgssapi is linked into libpq if needed (Markus Schaaf) Fix ecpg's parsing of CREATE ROLE (Michael) Fix recent breakage of pg_ctl restart (Tom) Ensure pg_control is opened in binary mode (Itagaki Takahiro) pg_controldata and pg_resetxlog did this incorrectly, and so could fail on Windows. Update time zone data files to tzdata release 2008i (for DST law changes in Argentina, Brazil, Mauritius, Syria) 2008-09-22 This release contains a variety of fixes from 8.3.3. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, if you are upgrading from a version earlier than 8.3.1, see the release notes for 8.3.1. Fix bug in btree WAL recovery code (Heikki) Recovery failed if the WAL ended partway through a page split operation. Fix potential use of wrong cutoff XID for HOT page pruning (Alvaro) This error created a risk of corruption in system catalogs that are consulted by VACUUM: dead tuple versions might be removed too soon. The impact of this on actual database operations would be minimal, since the system doesn't follow MVCC rules while examining catalogs, but it might result in transiently wrong output from pg_dump or other client programs. Fix potential miscalculation of datfrozenxid (Alvaro) This error may explain some recent reports of failure to remove old pg_clog data. Fix incorrect HOT updates after pg_class is reindexed (Tom) Corruption of pg_class could occur if REINDEX TABLE pg_class was followed in the same session by an ALTER TABLE RENAME or ALTER TABLE SET SCHEMA command. Fix missed combo cid case (Karl Schnaitter) This error made rows incorrectly invisible to a transaction in which they had been deleted by multiple subtransactions that all aborted. Prevent autovacuum from crashing if the table it's currently checking is deleted at just the wrong time (Alvaro) Widen local lock counters from 32 to 64 bits (Tom) This responds to reports that the counters could overflow in sufficiently long transactions, leading to unexpected lock is already held errors. Fix possible duplicate output of tuples during a GiST index scan (Teodor) Regenerate foreign key checking queries from scratch when either table is modified (Tom) Previously, 8.3 would attempt to replan the query, but would work from previously generated query text. This led to failures if a table or column was renamed. Fix missed permissions checks when a view contains a simple UNION ALL construct (Heikki) Permissions for the referenced tables were checked properly, but not permissions for the view itself. Add checks in executor startup to ensure that the tuples produced by an INSERT or UPDATE will match the target table's current rowtype (Tom) This situation is believed to be impossible in 8.3, but it can happen in prior releases, so a check seems prudent. Fix possible repeated drops during DROP OWNED (Tom) This would typically result in strange errors such as cache lookup failed for relation NNN. Fix several memory leaks in XML operations (Kris Jurka, Tom) Fix xmlserialize() to raise error properly for unacceptable target data type (Tom) Fix a couple of places that mis-handled multibyte characters in text search configuration file parsing (Tom) Certain characters occurring in configuration files would always cause invalid byte sequence for encoding failures. Provide file name and line number location for all errors reported in text search configuration files (Tom) Fix AT TIME ZONE to first try to interpret its timezone argument as a timezone abbreviation, and only try it as a full timezone name if that fails, rather than the other way around as formerly (Tom) The timestamp input functions have always resolved ambiguous zone names in this order. Making AT TIME ZONE do so as well improves consistency, and fixes a compatibility bug introduced in 8.1: in ambiguous cases we now behave the same as 8.0 and before did, since in the older versions AT TIME ZONE accepted only abbreviations. Fix datetime input functions to correctly detect integer overflow when running on a 64-bit platform (Tom) Prevent integer overflows during units conversion when displaying a configuration parameter that has units (Tom) Improve performance of writing very long log messages to syslog (Tom) Allow spaces in the suffix part of an LDAP URL in pg_hba.conf (Tom) Fix bug in backwards scanning of a cursor on a SELECT DISTINCT ON query (Tom) Fix planner bug that could improperly push down IS NULL tests below an outer join (Tom) This was triggered by occurrence of IS NULL tests for the same relation in all arms of an upper OR clause. Fix planner bug with nested sub-select expressions (Tom) If the outer sub-select has no direct dependency on the parent query, but the inner one does, the outer value might not get recalculated for new parent query rows. Fix planner to estimate that GROUP BY expressions yielding boolean results always result in two groups, regardless of the expressions' contents (Tom) This is very substantially more accurate than the regular GROUP BY estimate for certain boolean tests like col IS NULL. Fix PL/PgSQL to not fail when a FOR loop's target variable is a record containing composite-type fields (Tom) Fix PL/Tcl to behave correctly with Tcl 8.5, and to be more careful about the encoding of data sent to or from Tcl (Tom) Improve performance of PQescapeBytea() (Rudolf Leitgeb) On Windows, work around a Microsoft bug by preventing libpq from trying to send more than 64kB per system call (Magnus) Fix ecpg to handle variables properly in SET commands (Michael) Improve pg_dump and pg_restore's error reporting after failure to send a SQL command (Tom) Fix pg_ctl to properly preserve postmaster command-line arguments across a restart (Bruce) Fix erroneous WAL file cutoff point calculation in pg_standby (Simon) Update time zone data files to tzdata release 2008f (for DST law changes in Argentina, Bahamas, Brazil, Mauritius, Morocco, Pakistan, Palestine, and Paraguay) 2008-06-12 This release contains one serious and one minor bug fix over 8.3.2. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, if you are upgrading from a version earlier than 8.3.1, see the release notes for 8.3.1. Make pg_get_ruledef() parenthesize negative constants (Tom) Before this fix, a negative constant in a view or rule might be dumped as, say, -42::integer, which is subtly incorrect: it should be (-42)::integer due to operator precedence rules. Usually this would make little difference, but it could interact with another recent patch to cause PostgreSQL to reject what had been a valid SELECT DISTINCT view query. Since this could result in pg_dump output failing to reload, it is being treated as a high-priority fix. The only released versions in which dump output is actually incorrect are 8.3.1 and 8.2.7. Make ALTER AGGREGATE ... OWNER TO update pg_shdepend (Tom) This oversight could lead to problems if the aggregate was later involved in a DROP OWNED or REASSIGN OWNED operation. never released This release contains a variety of fixes from 8.3.1. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, if you are upgrading from a version earlier than 8.3.1, see the release notes for 8.3.1. Fix ERRORDATA_STACK_SIZE exceeded crash that occurred on Windows when using UTF-8 database encoding and a different client encoding (Tom) Fix incorrect archive truncation point calculation for the %r macro in recovery_command parameters (Simon) This could lead to data loss if a warm-standby script relied on %r to decide when to throw away WAL segment files. Fix ALTER TABLE ADD COLUMN ... PRIMARY KEY so that the new column is correctly checked to see if it's been initialized to all non-nulls (Brendan Jurd) Previous versions neglected to check this requirement at all. Fix REASSIGN OWNED so that it works on procedural languages too (Alvaro) Fix problems with SELECT FOR UPDATE/SHARE occurring as a subquery in a query with a non-SELECT top-level operation (Tom) Fix possible CREATE TABLE failure when inheriting the same constraint from multiple parent relations that inherited that constraint from a common ancestor (Tom) Fix pg_get_ruledef() to show the alias, if any, attached to the target table of an UPDATE or DELETE (Tom) Restore the pre-8.3 behavior that an out-of-range block number in a TID being used in a TidScan plan results in silently not matching any rows (Tom) 8.3.0 and 8.3.1 threw an error instead. Fix GIN bug that could result in a too many LWLocks taken failure (Teodor) Fix broken GiST comparison function for tsquery (Teodor) Fix tsvector_update_trigger() and ts_stat() to accept domains over the types they expect to work with (Tom) Fix failure to support enum data types as foreign keys (Tom) Avoid possible crash when decompressing corrupted data (Zdenek Kotala) Fix race conditions between delayed unlinks and DROP DATABASE (Heikki) In the worst case this could result in deleting a newly created table in a new database that happened to get the same OID as the recently-dropped one; but of course that is an extremely low-probability scenario. Repair two places where SIGTERM exit of a backend could leave corrupted state in shared memory (Tom) Neither case is very important if SIGTERM is used to shut down the whole database cluster together, but there was a problem if someone tried to SIGTERM individual backends. Fix possible crash due to incorrect plan generated for an x IN (SELECT y FROM ...) clause when x and y have different data types; and make sure the behavior is semantically correct when the conversion from y's type to x's type is lossy (Tom) Fix oversight that prevented the planner from substituting known Param values as if they were constants (Tom) This mistake partially disabled optimization of unnamed extended-Query statements in 8.3.0 and 8.3.1: in particular the LIKE-to-indexscan optimization would never be applied if the LIKE pattern was passed as a parameter, and constraint exclusion depending on a parameter value didn't work either. Fix planner failure when an indexable MIN or MAX aggregate is used with DISTINCT or ORDER BY (Tom) Fix planner to ensure it never uses a physical tlist for a plan node that is feeding a Sort node (Tom) This led to the sort having to push around more data than it really needed to, since unused column values were included in the sorted data. Avoid unnecessary copying of query strings (Tom) This fixes a performance problem introduced in 8.3.0 when a very large number of commands are submitted as a single query string. Make TransactionIdIsCurrentTransactionId() use binary search instead of linear search when checking child-transaction XIDs (Heikki) This fixes some cases in which 8.3.0 was significantly slower than earlier releases. Fix conversions between ISO-8859-5 and other encodings to handle Cyrillic Yo characters (e and E with two dots) (Sergey Burladyan) Fix several datatype input functions, notably array_in(), that were allowing unused bytes in their results to contain uninitialized, unpredictable values (Tom) This could lead to failures in which two apparently identical literal values were not seen as equal, resulting in the parser complaining about unmatched ORDER BY and DISTINCT expressions. Fix a corner case in regular-expression substring matching (substring(string from pattern)) (Tom) The problem occurs when there is a match to the pattern overall but the user has specified a parenthesized subexpression and that subexpression hasn't got a match. An example is substring('foo' from 'foo(bar)?'). This should return NULL, since (bar) isn't matched, but it was mistakenly returning the whole-pattern match instead (ie, foo). Prevent cancellation of an auto-vacuum that was launched to prevent XID wraparound (Alvaro) Improve ANALYZE's handling of in-doubt tuples (those inserted or deleted by a not-yet-committed transaction) so that the counts it reports to the stats collector are more likely to be correct (Pavan Deolasee) Fix initdb to reject a relative path for its --xlogdir (-X) option (Tom) Make psql print tab characters as an appropriate number of spaces, rather than \x09 as was done in 8.3.0 and 8.3.1 (Bruce) Update time zone data files to tzdata release 2008c (for DST law changes in Morocco, Iraq, Choibalsan, Pakistan, Syria, Cuba, and Argentina/San_Luis) Add ECPGget_PGconn() function to ecpglib (Michael) Fix incorrect result from ecpg's PGTYPEStimestamp_sub() function (Michael) Fix handling of continuation line markers in ecpg (Michael) Fix possible crashes in contrib/cube functions (Tom) Fix core dump in contrib/xml2's xpath_table() function when the input query returns a NULL value (Tom) Fix contrib/xml2's makefile to not override CFLAGS, and make it auto-configure properly for libxslt present or not (Tom) 2008-03-17 This release contains a variety of fixes from 8.3.0. For information about new features in the 8.3 major release, see . A dump/restore is not required for those running 8.3.X. However, you might need to REINDEX indexes on textual columns after updating, if you are affected by the Windows locale issue described below. Fix character string comparison for Windows locales that consider different character combinations as equal (Tom) This fix applies only on Windows and only when using UTF-8 database encoding. The same fix was made for all other cases over two years ago, but Windows with UTF-8 uses a separate code path that was not updated. If you are using a locale that considers some non-identical strings as equal, you may need to REINDEX to fix existing indexes on textual columns. Repair corner-case bugs in VACUUM FULL (Tom) A potential deadlock between concurrent VACUUM FULL operations on different system catalogs was introduced in 8.2. This has now been corrected. 8.3 made this worse because the deadlock could occur within a critical code section, making it a PANIC rather than just ERROR condition. Also, a VACUUM FULL that failed partway through vacuuming a system catalog could result in cache corruption in concurrent database sessions. Another VACUUM FULL bug introduced in 8.3 could result in a crash or out-of-memory report when dealing with pages containing no live tuples. Fix misbehavior of foreign key checks involving character or bit columns (Tom) If the referencing column were of a different but compatible type (for instance varchar), the constraint was enforced incorrectly. Avoid needless deadlock failures in no-op foreign-key checks (Stephan Szabo, Tom) Fix possible core dump when re-planning a prepared query (Tom) This bug affected only protocol-level prepare operations, not SQL PREPARE, and so tended to be seen only with JDBC, DBI, and other client-side drivers that use prepared statements heavily. Fix possible failure when re-planning a query that calls an SPI-using function (Tom) Fix failure in row-wise comparisons involving columns of different datatypes (Tom) Fix longstanding LISTEN/NOTIFY race condition (Tom) In rare cases a session that had just executed a LISTEN might not get a notification, even though one would be expected because the concurrent transaction executing NOTIFY was observed to commit later. A side effect of the fix is that a transaction that has executed a not-yet-committed LISTEN command will not see any row in pg_listener for the LISTEN, should it choose to look; formerly it would have. This behavior was never documented one way or the other, but it is possible that some applications depend on the old behavior. Disallow LISTEN and UNLISTEN within a prepared transaction (Tom) This was formerly allowed but trying to do it had various unpleasant consequences, notably that the originating backend could not exit as long as an UNLISTEN remained uncommitted. Disallow dropping a temporary table within a prepared transaction (Heikki) This was correctly disallowed by 8.1, but the check was inadvertently broken in 8.2 and 8.3. Fix rare crash when an error occurs during a query using a hash index (Heikki) Fix incorrect comparison of tsquery values (Teodor) Fix incorrect behavior of LIKE with non-ASCII characters in single-byte encodings (Rolf Jentsch) Disable xmlvalidate (Tom) This function should have been removed before 8.3 release, but was inadvertently left in the source code. It poses a small security risk since unprivileged users could use it to read the first few characters of any file accessible to the server. Fix memory leaks in certain usages of set-returning functions (Neil) Make encode(bytea, 'escape') convert all high-bit-set byte values into \nnn octal escape sequences (Tom) This is necessary to avoid encoding problems when the database encoding is multi-byte. This change could pose compatibility issues for applications that are expecting specific results from encode. Fix input of datetime values for February 29 in years BC (Tom) The former coding was mistaken about which years were leap years. Fix unrecognized node type error in some variants of ALTER OWNER (Tom) Avoid tablespace permissions errors in CREATE TABLE LIKE INCLUDING INDEXES (Tom) Ensure pg_stat_activity.waiting flag is cleared when a lock wait is aborted (Tom) Fix handling of process permissions on Windows Vista (Dave, Magnus) In particular, this fix allows starting the server as the Administrator user. Update time zone data files to tzdata release 2008a (in particular, recent Chile changes); adjust timezone abbreviation VET (Venezuela) to mean UTC-4:30, not UTC-4:00 (Tom) Fix ecpg problems with arrays (Michael) Fix pg_ctl to correctly extract the postmaster's port number from command-line options (Itagaki Takahiro, Tom) Previously, pg_ctl start -w could try to contact the postmaster on the wrong port, leading to bogus reports of startup failure. Use -fwrapv to defend against possible misoptimization in recent gcc versions (Tom) This is known to be necessary when building PostgreSQL with gcc 4.3 or later. Enable building contrib/uuid-ossp with MSVC (Hiroshi Saito) 2008-02-04 With significant new functionality and performance enhancements, this release represents a major leap forward for PostgreSQL. This was made possible by a growing community that has dramatically accelerated the pace of development. This release adds the following major features: Full text search is integrated into the core database system Support for the SQL/XML standard, including new operators and an XML data type Enumerated data types (ENUM) Arrays of composite types Universally Unique Identifier (UUID) data type Add control over whether NULLs sort first or last Updatable cursors Server configuration parameters can now be set on a per-function basis User-defined types can now have type modifiers Automatically re-plan cached queries when table definitions change or statistics are updated Numerous improvements in logging and statistics collection Support Security Service Provider Interface (SSPI) for authentication on Windows Support multiple concurrent autovacuum processes, and other autovacuum improvements Allow the whole PostgreSQL distribution to be compiled with Microsoft Visual C++ Major performance improvements are listed below. Most of these enhancements are automatic and do not require user changes or tuning: Asynchronous commit delays writes to WAL during transaction commit Checkpoint writes can be spread over a longer time period to smooth the I/O spike during each checkpoint Heap-Only Tuples (HOT) accelerate space reuse for most UPDATEs and DELETEs Just-in-time background writer strategy improves disk write efficiency Using non-persistent transaction IDs for read-only transactions reduces overhead and VACUUM requirements Per-field and per-row storage overhead has been reduced Large sequential scans no longer force out frequently used cached pages Concurrent large sequential scans can now share disk reads ORDER BY ... LIMIT can be done without sorting The above items are explained in more detail in the sections below. A dump/restore using pg_dump is required for those wishing to migrate data from any previous release. Observe the following incompatibilities: Non-character data types are no longer automatically cast to TEXT (Peter, Tom) Previously, if a non-character value was supplied to an operator or function that requires text input, it was automatically cast to text, for most (though not all) built-in data types. This no longer happens: an explicit cast to text is now required for all non-character-string types. For example, these expressions formerly worked: substr(current_date, 1, 4) 23 LIKE '2%' but will now draw function does not exist and operator does not exist errors respectively. Use an explicit cast instead: substr(current_date::text, 1, 4) 23::text LIKE '2%' (Of course, you can use the more verbose CAST() syntax too.) The reason for the change is that these automatic casts too often caused surprising behavior. An example is that in previous releases, this expression was accepted but did not do what was expected: current_date < 2017-11-17 This is actually comparing a date to an integer, which should be (and now is) rejected — but in the presence of automatic casts both sides were cast to text and a textual comparison was done, because the text < text operator was able to match the expression when no other < operator could. Types char(n) and varchar(n) still cast to text automatically. Also, automatic casting to text still works for inputs to the concatenation (||) operator, so long as least one input is a character-string type. Full text search features from contrib/tsearch2 have been moved into the core server, with some minor syntax changes contrib/tsearch2 now contains a compatibility interface. ARRAY(SELECT ...), where the SELECT returns no rows, now returns an empty array, rather than NULL (Tom) The array type name for a base data type is no longer always the base type's name with an underscore prefix The old naming convention is still honored when possible, but application code should no longer depend on it. Instead use the new pg_type.typarray column to identify the array data type associated with a given type. ORDER BY ... USING operator must now use a less-than or greater-than operator that is defined in a btree operator class This restriction was added to prevent inconsistent results. SET LOCAL changes now persist until the end of the outermost transaction, unless rolled back (Tom) Previously SET LOCAL's effects were lost after subtransaction commit (RELEASE SAVEPOINT or exit from a PL/pgSQL exception block). Commands rejected in transaction blocks are now also rejected in multiple-statement query strings (Tom) For example, "BEGIN; DROP DATABASE; COMMIT" will now be rejected even if submitted as a single query message. ROLLBACK outside a transaction block now issues NOTICE instead of WARNING (Bruce) Prevent NOTIFY/LISTEN/UNLISTEN from accepting schema-qualified names (Bruce) Formerly, these commands accepted schema.relation but ignored the schema part, which was confusing. ALTER SEQUENCE no longer affects the sequence's currval() state (Tom) Foreign keys now must match indexable conditions for cross-data-type references (Tom) This improves semantic consistency and helps avoid performance problems. Restrict object size functions to users who have reasonable permissions to view such information (Tom) For example, pg_database_size() now requires CONNECT permission, which is granted to everyone by default. pg_tablespace_size() requires CREATE permission in the tablespace, or is allowed if the tablespace is the default tablespace for the database. Remove the undocumented !!= (not in) operator (Tom) NOT IN (SELECT ...) is the proper way to perform this operation. Internal hashing functions are now more uniformly-distributed (Tom) If application code was computing and storing hash values using internal PostgreSQL hashing functions, the hash values must be regenerated. C-code conventions for handling variable-length data values have changed (Greg Stark, Tom) The new SET_VARSIZE() macro must be used to set the length of generated varlena values. Also, it might be necessary to expand (de-TOAST) input values in more cases. Continuous archiving no longer reports each successful archive operation to the server logs unless DEBUG level is used (Simon) Numerous changes in administrative server parameters bgwriter_lru_percent, bgwriter_all_percent, bgwriter_all_maxpages, stats_start_collector, and stats_reset_on_server_start are removed. redirect_stderr is renamed to logging_collector. stats_command_string is renamed to track_activities. stats_block_level and stats_row_level are merged into track_counts. A new boolean configuration parameter, archive_mode, controls archiving. Autovacuum's default settings have changed. Remove stats_start_collector parameter (Tom) We now always start the collector process, unless UDP socket creation fails. Remove stats_reset_on_server_start parameter (Tom) This was removed because pg_stat_reset() can be used for this purpose. Commenting out a parameter in postgresql.conf now causes it to revert to its default value (Joachim Wieland) Previously, commenting out an entry left the parameter's value unchanged until the next server restart. Add more checks for invalidly-encoded data (Andrew) This change plugs some holes that existed in literal backslash escape string processing and COPY escape processing. Now the de-escaped string is rechecked to see if the result created an invalid multi-byte character. Disallow database encodings that are inconsistent with the server's locale setting (Tom) On most platforms, C locale is the only locale that will work with any database encoding. Other locale settings imply a specific encoding and will misbehave if the database encoding is something different. (Typical symptoms include bogus textual sort order and wrong results from upper() or lower().) The server now rejects attempts to create databases that have an incompatible encoding. Ensure that chr() cannot create invalidly-encoded values (Andrew) In UTF8-encoded databases the argument of chr() is now treated as a Unicode code point. In other multi-byte encodings chr()'s argument must designate a 7-bit ASCII character. Zero is no longer accepted. ascii() has been adjusted to match. Adjust convert() behavior to ensure encoding validity (Andrew) The two argument form of convert() has been removed. The three argument form now takes a bytea first argument and returns a bytea. To cover the loss of functionality, three new functions have been added: convert_from(bytea, name) returns text — converts the first argument from the named encoding to the database encoding convert_to(text, name) returns bytea — converts the first argument from the database encoding to the named encoding length(bytea, name) returns integer — gives the length of the first argument in characters in the named encoding Remove convert(argument USING conversion_name) (Andrew) Its behavior did not match the SQL standard. Make JOHAB encoding client-only (Tatsuo) JOHAB is not safe as a server-side encoding. Below you will find a detailed account of the changes between PostgreSQL 8.3 and the previous major release. Asynchronous commit delays writes to WAL during transaction commit (Simon) This feature dramatically increases performance for short data-modifying transactions. The disadvantage is that because disk writes are delayed, if the database or operating system crashes before data is written to the disk, committed data will be lost. This feature is useful for applications that can accept some data loss. Unlike turning off fsync, using asynchronous commit does not put database consistency at risk; the worst case is that after a crash the last few reportedly-committed transactions might not be committed after all. This feature is enabled by turning off synchronous_commit (which can be done per-session or per-transaction, if some transactions are critical and others are not). wal_writer_delay can be adjusted to control the maximum delay before transactions actually reach disk. Checkpoint writes can be spread over a longer time period to smooth the I/O spike during each checkpoint (Itagaki Takahiro and Heikki Linnakangas) Previously all modified buffers were forced to disk as quickly as possible during a checkpoint, causing an I/O spike that decreased server performance. This new approach spreads out disk writes during checkpoints, reducing peak I/O usage. (User-requested and shutdown checkpoints are still written as quickly as possible.) Heap-Only Tuples (HOT) accelerate space reuse for most UPDATEs and DELETEs (Pavan Deolasee, with ideas from many others) UPDATEs and DELETEs leave dead tuples behind, as do failed INSERTs. Previously only VACUUM could reclaim space taken by dead tuples. With HOT dead tuple space can be automatically reclaimed at the time of INSERT or UPDATE if no changes are made to indexed columns. This allows for more consistent performance. Also, HOT avoids adding duplicate index entries. Just-in-time background writer strategy improves disk write efficiency (Greg Smith, Itagaki Takahiro) This greatly reduces the need for manual tuning of the background writer. Per-field and per-row storage overhead have been reduced (Greg Stark, Heikki Linnakangas) Variable-length data types with data values less than 128 bytes long will see a storage decrease of 3 to 6 bytes. For example, two adjacent char(1) fields now use 4 bytes instead of 16. Row headers are also 4 bytes shorter than before. Using non-persistent transaction IDs for read-only transactions reduces overhead and VACUUM requirements (Florian Pflug) Non-persistent transaction IDs do not increment the global transaction counter. Therefore, they reduce the load on pg_clog and increase the time between forced vacuums to prevent transaction ID wraparound. Other performance improvements were also made that should improve concurrency. Avoid incrementing the command counter after a read-only command (Tom) There was formerly a hard limit of 232 (4 billion) commands per transaction. Now only commands that actually changed the database count, so while this limit still exists, it should be significantly less annoying. Create a dedicated WAL writer process to off-load work from backends (Simon) Skip unnecessary WAL writes for CLUSTER and COPY (Simon) Unless WAL archiving is enabled, the system now avoids WAL writes for CLUSTER and just fsync()s the table at the end of the command. It also does the same for COPY if the table was created in the same transaction. Large sequential scans no longer force out frequently used cached pages (Simon, Heikki, Tom) Concurrent large sequential scans can now share disk reads (Jeff Davis) This is accomplished by starting the new sequential scan in the middle of the table (where another sequential scan is already in-progress) and wrapping around to the beginning to finish. This can affect the order of returned rows in a query that does not specify ORDER BY. The synchronize_seqscans configuration parameter can be used to disable this if necessary. ORDER BY ... LIMIT can be done without sorting (Greg Stark) This is done by sequentially scanning the table and tracking just the top N candidate rows, rather than performing a full sort of the entire table. This is useful when there is no matching index and the LIMIT is not large. Put a rate limit on messages sent to the statistics collector by backends (Tom) This reduces overhead for short transactions, but might sometimes increase the delay before statistics are tallied. Improve hash join performance for cases with many NULLs (Tom) Speed up operator lookup for cases with non-exact datatype matches (Tom) Autovacuum is now enabled by default (Alvaro) Several changes were made to eliminate disadvantages of having autovacuum enabled, thereby justifying the change in default. Several other autovacuum parameter defaults were also modified. Support multiple concurrent autovacuum processes (Alvaro, Itagaki Takahiro) This allows multiple vacuums to run concurrently. This prevents vacuuming of a large table from delaying vacuuming of smaller tables. Automatically re-plan cached queries when table definitions change or statistics are updated (Tom) Previously PL/PgSQL functions that referenced temporary tables would fail if the temporary table was dropped and recreated between function invocations, unless EXECUTE was used. This improvement fixes that problem and many related issues. Add a temp_tablespaces parameter to control the tablespaces for temporary tables and files (Jaime Casanova, Albert Cervera, Bernd Helmle) This parameter defines a list of tablespaces to be used. This enables spreading the I/O load across multiple tablespaces. A random tablespace is chosen each time a temporary object is created. Temporary files are no longer stored in per-database pgsql_tmp/ directories but in per-tablespace directories. Place temporary tables' TOAST tables in special schemas named pg_toast_temp_nnn (Tom) This allows low-level code to recognize these tables as temporary, which enables various optimizations such as not WAL-logging changes and using local rather than shared buffers for access. This also fixes a bug wherein backends unexpectedly held open file references to temporary TOAST tables. Fix problem that a constant flow of new connection requests could indefinitely delay the postmaster from completing a shutdown or a crash restart (Tom) Guard against a very-low-probability data loss scenario by preventing re-use of a deleted table's relfilenode until after the next checkpoint (Heikki) Fix CREATE CONSTRAINT TRIGGER to convert old-style foreign key trigger definitions into regular foreign key constraints (Tom) This will ease porting of foreign key constraints carried forward from pre-7.3 databases, if they were never converted using contrib/adddepend. Fix DEFAULT NULL to override inherited defaults (Tom) DEFAULT NULL was formerly considered a noise phrase, but it should (and now does) override non-null defaults that would otherwise be inherited from a parent table or domain. Add new encodings EUC_JIS_2004 and SHIFT_JIS_2004 (Tatsuo) These new encodings can be converted to and from UTF-8. Change server startup log message from database system is ready to database system is ready to accept connections, and adjust its timing The message now appears only when the postmaster is really ready to accept connections. Add log_autovacuum_min_duration parameter to support configurable logging of autovacuum activity (Simon, Alvaro) Add log_lock_waits parameter to log lock waiting (Simon) Add log_temp_files parameter to log temporary file usage (Bill Moran) Add log_checkpoints parameter to improve logging of checkpoints (Greg Smith, Heikki) log_line_prefix now supports %s and %c escapes in all processes (Andrew) Previously these escapes worked only for user sessions, not for background database processes. Add log_restartpoints to control logging of point-in-time recovery restart points (Simon) Last transaction end time is now logged at end of recovery and at each logged restart point (Simon) Autovacuum now reports its activity start time in pg_stat_activity (Tom) Allow server log output in comma-separated value (CSV) format (Arul Shaji, Greg Smith, Andrew Dunstan) CSV-format log files can easily be loaded into a database table for subsequent analysis. Use PostgreSQL-supplied timezone support for formatting timestamps displayed in the server log (Tom) This avoids Windows-specific problems with localized time zone names that are in the wrong encoding. There is a new log_timezone parameter that controls the timezone used in log messages, independently of the client-visible timezone parameter. New system view pg_stat_bgwriter displays statistics about background writer activity (Magnus) Add new columns for database-wide tuple statistics to pg_stat_database (Magnus) Add an xact_start (transaction start time) column to pg_stat_activity (Neil) This makes it easier to identify long-running transactions. Add n_live_tuples and n_dead_tuples columns to pg_stat_all_tables and related views (Glen Parker) Merge stats_block_level and stats_row_level parameters into a single parameter track_counts, which controls all messages sent to the statistics collector process (Tom) Rename stats_command_string parameter to track_activities (Tom) Fix statistical counting of live and dead tuples to recognize that committed and aborted transactions have different effects (Tom) Support Security Service Provider Interface (SSPI) for authentication on Windows (Magnus) Support GSSAPI authentication (Henry Hotz, Magnus) This should be preferred to native Kerberos authentication because GSSAPI is an industry standard. Support a global SSL configuration file (Victor Wagner) Add ssl_ciphers parameter to control accepted SSL ciphers (Victor Wagner) Add a Kerberos realm parameter, krb_realm (Magnus) Change the timestamps recorded in transaction WAL records from time_t to TimestampTz representation (Tom) This provides sub-second resolution in WAL, which can be useful for point-in-time recovery. Reduce WAL disk space needed by warm standby servers (Simon) This change allows a warm standby server to pass the name of the earliest still-needed WAL file to the recovery script, allowing automatic removal of no-longer-needed WAL files. This is done using %r in the restore_command parameter of recovery.conf. New boolean configuration parameter, archive_mode, controls archiving (Simon) Previously setting archive_command to an empty string turned off archiving. Now archive_mode turns archiving on and off, independently of archive_command. This is useful for stopping archiving temporarily. Full text search is integrated into the core database system (Teodor, Oleg) Text search has been improved, moved into the core code, and is now installed by default. contrib/tsearch2 now contains a compatibility interface. Add control over whether NULLs sort first or last (Teodor, Tom) The syntax is ORDER BY ... NULLS FIRST/LAST. Allow per-column ascending/descending (ASC/DESC) ordering options for indexes (Teodor, Tom) Previously a query using ORDER BY with mixed ASC/DESC specifiers could not fully use an index. Now an index can be fully used in such cases if the index was created with matching ASC/DESC specifications. NULL sort order within an index can be controlled, too. Allow col IS NULL to use an index (Teodor) Updatable cursors (Arul Shaji, Tom) This eliminates the need to reference a primary key to UPDATE or DELETE rows returned by a cursor. The syntax is UPDATE/DELETE WHERE CURRENT OF. Allow FOR UPDATE in cursors (Arul Shaji, Tom) Create a general mechanism that supports casts to and from the standard string types (TEXT, VARCHAR, CHAR) for every datatype, by invoking the datatype's I/O functions (Tom) Previously, such casts were available only for types that had specialized function(s) for the purpose. These new casts are assignment-only in the to-string direction, explicit-only in the other direction, and therefore should create no surprising behavior. Allow UNION and related constructs to return a domain type, when all inputs are of that domain type (Tom) Formerly, the output would be considered to be of the domain's base type. Allow limited hashing when using two different data types (Tom) This allows hash joins, hash indexes, hashed subplans, and hash aggregation to be used in situations involving cross-data-type comparisons, if the data types have compatible hash functions. Currently, cross-data-type hashing support exists for smallint/integer/bigint, and for float4/float8. Improve optimizer logic for detecting when variables are equal in a WHERE clause (Tom) This allows mergejoins to work with descending sort orders, and improves recognition of redundant sort columns. Improve performance when planning large inheritance trees in cases where most tables are excluded by constraints (Tom) Arrays of composite types (David Fetter, Andrew, Tom) In addition to arrays of explicitly-declared composite types, arrays of the rowtypes of regular tables and views are now supported, except for rowtypes of system catalogs, sequences, and TOAST tables. Server configuration parameters can now be set on a per-function basis (Tom) For example, functions can now set their own search_path to prevent unexpected behavior if a different search_path exists at run-time. Security definer functions should set search_path to avoid security loopholes. CREATE/ALTER FUNCTION now supports COST and ROWS options (Tom) COST allows specification of the cost of a function call. ROWS allows specification of the average number or rows returned by a set-returning function. These values are used by the optimizer in choosing the best plan. Implement CREATE TABLE LIKE ... INCLUDING INDEXES (Trevor Hardcastle, Nikhil Sontakke, Neil) Allow CREATE INDEX CONCURRENTLY to ignore transactions in other databases (Simon) Add ALTER VIEW ... RENAME TO and ALTER SEQUENCE ... RENAME TO (David Fetter, Neil) Previously this could only be done via ALTER TABLE ... RENAME TO. Make CREATE/DROP/RENAME DATABASE wait briefly for conflicting backends to exit before failing (Tom) This increases the likelihood that these commands will succeed. Allow triggers and rules to be deactivated in groups using a configuration parameter, for replication purposes (Jan) This allows replication systems to disable triggers and rewrite rules as a group without modifying the system catalogs directly. The behavior is controlled by ALTER TABLE and a new parameter session_replication_role. User-defined types can now have type modifiers (Teodor, Tom) This allows a user-defined type to take a modifier, like ssnum(7). Previously only built-in data types could have modifiers. Non-superuser database owners now are able to add trusted procedural languages to their databases by default (Jeremy Drake) While this is reasonably safe, some administrators might wish to revoke the privilege. It is controlled by pg_pltemplate.tmpldbacreate. Allow a session's current parameter setting to be used as the default for future sessions (Tom) This is done with SET ... FROM CURRENT in CREATE/ALTER FUNCTION, ALTER DATABASE, or ALTER ROLE. Implement new commands DISCARD ALL, DISCARD PLANS, DISCARD TEMPORARY, CLOSE ALL, and DEALLOCATE ALL (Marko Kreen, Neil) These commands simplify resetting a database session to its initial state, and are particularly useful for connection-pooling software. Make CLUSTER MVCC-safe (Heikki Linnakangas) Formerly, CLUSTER would discard all tuples that were committed dead, even if there were still transactions that should be able to see them under MVCC visibility rules. Add new CLUSTER syntax: CLUSTER table USING index (Holger Schurig) The old CLUSTER syntax is still supported, but the new form is considered more logical. Fix EXPLAIN so it can show complex plans more accurately (Tom) References to subplan outputs are now always shown correctly, instead of using ?columnN? for complicated cases. Limit the amount of information reported when a user is dropped (Alvaro) Previously, dropping (or attempting to drop) a user who owned many objects could result in large NOTICE or ERROR messages listing all these objects; this caused problems for some client applications. The length of the message is now limited, although a full list is still sent to the server log. Support for the SQL/XML standard, including new operators and an XML data type (Nikolay Samokhvalov, Pavel Stehule, Peter) Enumerated data types (ENUM) (Tom Dunstan) This feature provides convenient support for fields that have a small, fixed set of allowed values. An example of creating an ENUM type is CREATE TYPE mood AS ENUM ('sad', 'ok', 'happy'). Universally Unique Identifier (UUID) data type (Gevik Babakhani, Neil) This closely matches RFC 4122. Widen the MONEY data type to 64 bits (D'Arcy Cain) This greatly increases the range of supported MONEY values. Fix float4/float8 to handle Infinity and NAN (Not A Number) consistently (Bruce) The code formerly was not consistent about distinguishing Infinity from overflow conditions. Allow leading and trailing whitespace during input of boolean values (Neil) Prevent COPY from using digits and lowercase letters as delimiters (Tom) Add new regular expression functions regexp_matches(), regexp_split_to_array(), and regexp_split_to_table() (Jeremy Drake, Neil) These functions provide extraction of regular expression subexpressions and allow splitting a string using a POSIX regular expression. Add lo_truncate() for large object truncation (Kris Jurka) Implement width_bucket() for the float8 data type (Neil) Add pg_stat_clear_snapshot() to discard statistics snapshots collected during the current transaction (Tom) The first request for statistics in a transaction takes a statistics snapshot that does not change during the transaction. This function allows the snapshot to be discarded and a new snapshot loaded during the next statistics query. This is particularly useful for PL/PgSQL functions, which are confined to a single transaction. Add isodow option to EXTRACT() and date_part() (Bruce) This returns the day of the week, with Sunday as seven. (dow returns Sunday as zero.) Add ID (ISO day of week) and IDDD (ISO day of year) format codes for to_char(), to_date(), and to_timestamp() (Brendan Jurd) Make to_timestamp() and to_date() assume TM (trim) option for potentially variable-width fields (Bruce) This matches Oracle's behavior. Fix off-by-one conversion error in to_date()/to_timestamp() D (non-ISO day of week) fields (Bruce) Make setseed() return void, rather than a useless integer value (Neil) Add a hash function for NUMERIC (Neil) This allows hash indexes and hash-based plans to be used with NUMERIC columns. Improve efficiency of LIKE/ILIKE, especially for multi-byte character sets like UTF-8 (Andrew, Itagaki Takahiro) Make currtid() functions require SELECT privileges on the target table (Tom) Add several txid_*() functions to query active transaction IDs (Jan) This is useful for various replication solutions. Add scrollable cursor support, including directional control in FETCH (Pavel Stehule) Allow IN as an alternative to FROM in PL/PgSQL's FETCH statement, for consistency with the backend's FETCH command (Pavel Stehule) Add MOVE to PL/PgSQL (Magnus, Pavel Stehule, Neil) Implement RETURN QUERY (Pavel Stehule, Neil) This adds convenient syntax for PL/PgSQL set-returning functions that want to return the result of a query. RETURN QUERY is easier and more efficient than a loop around RETURN NEXT. Allow function parameter names to be qualified with the function's name (Tom) For example, myfunc.myvar. This is particularly useful for specifying variables in a query where the variable name might match a column name. Make qualification of variables with block labels work properly (Tom) Formerly, outer-level block labels could unexpectedly interfere with recognition of inner-level record or row references. Tighten requirements for FOR loop STEP values (Tom) Prevent non-positive STEP values, and handle loop overflows. Improve accuracy when reporting syntax error locations (Tom) Allow type-name arguments to PL/Perl spi_prepare() to be data type aliases in addition to names found in pg_type (Andrew) Allow type-name arguments to PL/Python plpy.prepare() to be data type aliases in addition to names found in pg_type (Andrew) Allow type-name arguments to PL/Tcl spi_prepare to be data type aliases in addition to names found in pg_type (Andrew) Enable PL/PythonU to compile on Python 2.5 (Marko Kreen) Support a true PL/Python boolean type in compatible Python versions (Python 2.3 and later) (Marko Kreen) Fix PL/Tcl problems with thread-enabled libtcl spawning multiple threads within the backend (Steve Marshall, Paul Bayer, Doug Knight) This caused all sorts of unpleasantness. List disabled triggers separately in \d output (Brendan Jurd) In \d patterns, always match $ literally (Tom) Show aggregate return types in \da output (Greg Sabino Mullane) Add the function's volatility status to the output of \df+ (Neil) Add \prompt capability (Chad Wagner) Allow \pset, \t, and \x to specify on or off, rather than just toggling (Chad Wagner) Add \sleep capability (Jan) Enable \timing output for \copy (Andrew) Improve \timing resolution on Windows (Itagaki Takahiro) Flush \o output after each backslash command (Tom) Correctly detect and report errors while reading a -f input file (Peter) Remove -u option (this option has long been deprecated) (Tom) Add --tablespaces-only and --roles-only options to pg_dumpall (Dave Page) Add an output file option to pg_dumpall (Dave Page) This is primarily useful on Windows, where output redirection of child pg_dump processes does not work. Allow pg_dumpall to accept an initial-connection database name rather than the default template1 (Dave Page) In -n and -t switches, always match $ literally (Tom) Improve performance when a database has thousands of objects (Tom) Remove -u option (this option has long been deprecated) (Tom) In initdb, allow the location of the pg_xlog directory to be specified (Euler Taveira de Oliveira) Enable server core dump generation in pg_regress on supported operating systems (Andrew) Add a -t (timeout) parameter to pg_ctl (Bruce) This controls how long pg_ctl will wait when waiting for server startup or shutdown. Formerly the timeout was hard-wired as 60 seconds. Add a pg_ctl option to control generation of server core dumps (Andrew) Allow Control-C to cancel clusterdb, reindexdb, and vacuumdb (Itagaki Takahiro, Magnus) Suppress command tag output for createdb, createuser, dropdb, and dropuser (Peter) The --quiet option is ignored and will be removed in 8.4. Progress messages when acting on all databases now go to stdout instead of stderr because they are not actually errors. Interpret the dbName parameter of PQsetdbLogin() as a conninfo string if it contains an equals sign (Andrew) This allows use of conninfo strings in client programs that still use PQsetdbLogin(). Support a global SSL configuration file (Victor Wagner) Add environment variable PGSSLKEY to control SSL hardware keys (Victor Wagner) Add lo_truncate() for large object truncation (Kris Jurka) Add PQconnectionNeedsPassword() that returns true if the server required a password but none was supplied (Joe Conway, Tom) If this returns true after a failed connection attempt, a client application should prompt the user for a password. In the past applications have had to check for a specific error message string to decide whether a password is needed; that approach is now deprecated. Add PQconnectionUsedPassword() that returns true if the supplied password was actually used (Joe Conway, Tom) This is useful in some security contexts where it is important to know whether a user-supplied password is actually valid. Use V3 frontend/backend protocol (Michael) This adds support for server-side prepared statements. Use native threads, instead of pthreads, on Windows (Magnus) Improve thread-safety of ecpglib (Itagaki Takahiro) Make the ecpg libraries export only necessary API symbols (Michael) Allow the whole PostgreSQL distribution to be compiled with Microsoft Visual C++ (Magnus and others) This allows Windows-based developers to use familiar development and debugging tools. Windows executables made with Visual C++ might also have better stability and performance than those made with other tool sets. The client-only Visual C++ build scripts have been removed. Drastically reduce postmaster's memory usage when it has many child processes (Magnus) Allow regression tests to be started by an administrative user (Magnus) Add native shared memory implementation (Magnus) Add cursor-related functionality in SPI (Pavel Stehule) Allow access to the cursor-related planning options, and add FETCH/MOVE routines. Allow execution of cursor commands through SPI_execute (Tom) The macro SPI_ERROR_CURSOR still exists but will never be returned. SPI plan pointers are now declared as SPIPlanPtr instead of void * (Tom) This does not break application code, but switching is recommended to help catch simple programming mistakes. Add configure option --enable-profiling to enable code profiling (works only with gcc) (Korry Douglas and Nikhil Sontakke) Add configure option --with-system-tzdata to use the operating system's time zone database (Peter) Fix PGXS so extensions can be built against PostgreSQL installations whose pg_config program does not appear first in the PATH (Tom) Support gmake draft when building the SGML documentation (Bruce) Unless draft is used, the documentation build will now be repeated if necessary to ensure the index is up-to-date. Rename macro DLLIMPORT to PGDLLIMPORT to avoid conflicting with third party includes (like Tcl) that define DLLIMPORT (Magnus) Create operator families to improve planning of queries involving cross-data-type comparisons (Tom) Update GIN extractQuery() API to allow signalling that nothing can satisfy the query (Teodor) Move NAMEDATALEN definition from postgres_ext.h to pg_config_manual.h (Peter) Provide strlcpy() and strlcat() on all platforms, and replace error-prone uses of strncpy(), strncat(), etc (Peter) Create hooks to let an external plugin monitor (or even replace) the planner and create plans for hypothetical situations (Gurjeet Singh, Tom) Create a function variable join_search_hook to let plugins override the join search order portion of the planner (Julius Stroffek) Add tas() support for Renesas' M32R processor (Kazuhiro Inaoka) quote_identifier() and pg_dump no longer quote keywords that are unreserved according to the grammar (Tom) Change the on-disk representation of the NUMERIC data type so that the sign_dscale word comes before the weight (Tom) Use SYSV semaphores rather than POSIX on Darwin >= 6.0, i.e., OS X 10.2 and up (Chris Marcellino) Add acronym and NFS documentation sections (Bruce) "Postgres" is now documented as an accepted alias for "PostgreSQL" (Peter) Add documentation about preventing database server spoofing when the server is down (Bruce) Move contrib README content into the main PostgreSQL documentation (Albert Cervera i Areny) Add contrib/pageinspect module for low-level page inspection (Simon, Heikki) Add contrib/pg_standby module for controlling warm standby operation (Simon) Add contrib/uuid-ossp module for generating UUID values using the OSSP UUID library (Peter) Use configure --with-ossp-uuid to activate. This takes advantage of the new UUID builtin type. Add contrib/dict_int, contrib/dict_xsyn, and contrib/test_parser modules to provide sample add-on text search dictionary templates and parsers (Sergey Karpov) Allow contrib/pgbench to set the fillfactor (Pavan Deolasee) Add timestamps to contrib/pgbench -l (Greg Smith) Add usage count statistics to contrib/pgbuffercache (Greg Smith) Add GIN support for contrib/hstore (Teodor) Add GIN support for contrib/pg_trgm (Guillaume Smet, Teodor) Update OS/X startup scripts in contrib/start-scripts (Mark Cotner, David Fetter) Restrict pgrowlocks() and dblink_get_pkey() to users who have SELECT privilege on the target table (Tom) Restrict contrib/pgstattuple functions to superusers (Tom) contrib/xml2 is deprecated and planned for removal in 8.4 (Peter) The new XML support in core PostgreSQL supersedes this module.