HISTORY

                                      
Added documentation to tarball.

     _________________________________________________________________
   
                               Release 7.0.1
                                      
     Release date: 2000-06-01
     
   This is a cleanup release for 7.0.
     _________________________________________________________________
   
                         Migration to version 7.0.1
                                      
   A dump/restore is *not* required for those running 7.0.
     _________________________________________________________________
   
                                  Changes
                                      
Fix many CLUSTER failures (Tom)
Allow ALTER TABLE RENAME works on indexes (Tom)
Fix plpgsql to handle datetime->timestamp and timespan->interval (Bruce)
New configure --with-setproctitle switch to use setproctitle() (Marc, Bruce)
Fix the off by one errors in ResultSet from 6.5.3, and more.
jdbc ResultSet fixes (Joseph Shraibman)
optimizer tunings (Tom)
Fix create user for pgaccess
Fix for UNLISTEN failure
IRIX fixes (David Kaelbling)
QNX fixes (Andreas Kardos)
Reduce COPY IN lock level (Tom)
Change libpqeasy to use PQconnectdb() style parameters (Bruce)
Fix pg_dump to handle OID indexes (Tom)
Fix small memory leak (Tom)
Solaris fix for createdb/dropdb (Tatsuo)
Fix for non-blocking connections (Alfred Perlstein)
Fix improper recovery after RENAME TABLE failures (Tom)
Copy pg_ident.conf.sample into /lib directory in install (Bruce)
Add SJIS UDC (NEC selection IBM kanji) support (Eiji Tokuya)
Fix too long syslog message (Tatsuo)
Fix problem with quoted indexes that are too long (Tom)
JDBC ResultSet.getTimestamp() fix (Gregory Krasnow & Floyd Marinescu)
ecpg changes (Michael)

     _________________________________________________________________
   
                                Release 7.0
                                      
     Release date: 2000-05-08
     
   This release contains improvements in many areas, demonstrating the
   continued growth of PostgreSQL. There are more improvements and fixes
   in 7.0 than in any previous release. The developers have confidence
   that this is the best release yet; we do our best to put out only
   solid releases, and this one is no exception.
   
   Major changes in this release:
   
   Foreign Keys
          Foreign keys are now implemented, with the exception of PARTIAL
          MATCH foreign keys. Many users have been asking for this
          feature, and we are pleased to offer it.
          
   Optimizer Overhaul
          Continuing on work started a year ago, the optimizer has been
          improved, allowing better query plan selection and faster
          performance with less memory usage.
          
   Updated psql
          psql, our interactive terminal monitor, has been updated with a
          variety of new features. See the psql manual page for details.
          
   Join Syntax
          SQL92 join syntax is now supported, though only as INNER JOIN
          for this release. JOIN, NATURAL JOIN, JOIN/USING, and JOIN/ON
          are available, as are column correlation names.
     _________________________________________________________________
   
                          Migration to version 7.0
                                      
   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release of PostgreSQL. For those upgrading from
   6.5.*, you may instead use pg_upgrade to upgrade to this release;
   however, a full dump/reload installation is always the most robust
   method for upgrades.
   
   Interface and compatibility issues to consider for the new release
   include:
   
     * The date/time types datetime and timespan have been superseded by
       the SQL92-defined types timestamp and interval. Although there has
       been some effort to ease the transition by allowing PostgreSQL to
       recognize the deprecated type names and translate them to the new
       type names, this mechanism may not be completely transparent to
       your existing application.
     * The optimizer has been substantially improved in the area of query
       cost estimation. In some cases, this will result in decreased
       query times as the optimizer makes a better choice for the
       preferred plan. However, in a small number of cases, usually
       involving pathological distributions of data, your query times may
       go up. If you are dealing with large amounts of data, you may want
       to check your queries to verify performance.
     * The JDBC and ODBC interfaces have been upgraded and extended.
     * The string function CHAR_LENGTH is now a native function. Previous
       versions translated this into a call to LENGTH, which could result
       in ambiguity with other types implementing LENGTH such as the
       geometric types.
     _________________________________________________________________
   
                                  Changes
                                      
Bug Fixes
---------
Prevent function calls exceeding maximum number of arguments (Tom)
Improve CASE construct (Tom)
Fix SELECT coalesce(f1,0) FROM int4_tbl GROUP BY f1 (Tom)
Fix SELECT sentence.words[0] FROM sentence GROUP BY sentence.words[0] (Tom)
Fix GROUP BY scan bug (Tom)
Improvements in SQL grammar processing (Tom)
Fix for views involved in INSERT ... SELECT ... (Tom)
Fix for SELECT a/2, a/2 FROM test_missing_target GROUP BY a/2 (Tom)
Fix for subselects in INSERT ... SELECT (Tom)
Prevent INSERT ... SELECT ... ORDER BY (Tom)
Fixes for relations greater than 2GB, including vacuum
Improve propagating system table changes to other backends (Tom)
Improve propagating user table changes to other backends (Tom)
Fix handling of temp tables in complex situations (Bruce, Tom)
Allow table locking at table open, improving concurrent reliability (Tom)
Properly quote sequence names in pg_dump (Ross J. Reedstrom)
Prevent DROP DATABASE while others accessing
Prevent any rows from being returned by GROUP BY if no rows processed (Tom)
Fix SELECT COUNT(1) FROM table WHERE ...' if no rows matching WHERE (Tom)
Fix pg_upgrade so it works for MVCC (Tom)
Fix for SELECT ... WHERE x IN (SELECT ... HAVING SUM(x) > 1) (Tom)
Fix for "f1 datetime DEFAULT 'now'"  (Tom)
Fix problems with CURRENT_DATE used in DEFAULT (Tom)
Allow comment-only lines, and ;;; lines too. (Tom)
Improve recovery after failed disk writes, disk full (Hiroshi)
Fix cases where table is mentioned in FROM but not joined (Tom)
Allow HAVING clause without aggregate functions (Tom)
Fix for "--" comment and no trailing newline, as seen in perl interface
Improve pg_dump failure error reports (Bruce)
Allow sorts and hashes to exceed 2GB file sizes (Tom)
Fix for pg_dump dumping of inherited rules (Tom)
Fix for NULL handling comparisons (Tom)
Fix inconsistent state caused by failed CREATE/DROP commands (Hiroshi)
Fix for dbname with dash
Prevent DROP INDEX from interfering with other backends (Tom)
Fix file descriptor leak in verify_password()
Fix for "Unable to identify an operator =$" problem
Fix ODBC so no segfault if CommLog and Debug enabled (Dirk Niggemann)
Fix for recursive exit call (Massimo)
Fix for extra-long timezones (Jeroen van Vianen)
Make pg_dump preserve primary key information (Peter E)
Prevent databases with single quotes (Peter E)
Prevent DROP DATABASE inside  transaction (Peter E)
ecpg memory leak fixes (Stephen Birch)
Fix for SELECT null::text, SELECT int4fac(null) and SELECT 2 + (null) (Tom)
Y2K timestamp fix (Massimo)
Fix for VACUUM 'HEAP_MOVED_IN was not expected' errors (Tom)
Fix for views with tables/columns containing spaces  (Tom)
Prevent permissions on indexes (Peter E)
Fix for spinlock stuck problem when error is generated (Hiroshi)
Fix ipcclean on Linux
Fix handling of NULL constraint conditions (Tom)
Fix memory leak in odbc driver (Nick Gorham)
Fix for permission check on UNION tables (Tom)
Fix to allow SELECT 'a' LIKE 'a' (Tom)
Fix for SELECT 1 + NULL (Tom)
Fixes to CHAR
Fix log() on numeric type (Tom)
Deprecate ':' and ';' operators
Allow vacuum of temporary tables
Disallow inherited columns with the same name as new columns
Recover or force failure when disk space is exhausted (Hiroshi)
Fix INSERT INTO ... SELECT with AS columns matching result columns
Fix INSERT ... SELECT ... GROUP BY groups by target columns not source columns
(Tom)
Fix CREATE TABLE test (a char(5) DEFAULT text '', b int4) with INSERT (Tom)
Fix UNION with LIMIT
Fix CREATE TABLE x AS SELECT 1 UNION SELECT 2
Fix CREATE TABLE test(col char(2) DEFAULT user)
Fix mismatched types in CREATE TABLE ... DEFAULT
Fix SELECT * FROM pg_class where oid in (0,-1)
Fix SELECT COUNT('asdf') FROM pg_class WHERE oid=12
Prevent user who can create databases can modifying pg_database table (Peter E)
Fix btree to give a useful elog when key > 1/2 (page - overhead) (Tom)
Fix INSERT of 0.0 into DECIMAL(4,4) field (Tom)

Enhancements
------------
New CLI interface include file sqlcli.h, based on SQL3/SQL98
Remove all limits on query length, row length limit still exists (Tom)
Update jdbc protocol to 2.0 (Jens Glaser <jens@jens.de>)
Add TRUNCATE command to quickly truncate relation (Mike Mascari)
Fix to give super user and createdb user proper update catalog rights (Peter E)
Allow ecpg bool variables to have NULL values (Christof)
Issue ecpg error if NULL value for variable with no NULL indicator (Christof)
Allow ^C to cancel COPY command (Massimo)
Add SET FSYNC and SHOW PG_OPTIONS commands(Massimo)
Function name overloading for dynamically-loaded C functions (Frankpitt)
Add CmdTuples() to libpq++(Vince)
New CREATE CONSTRAINT TRIGGER and SET CONSTRAINTS commands(Jan)
Allow CREATE FUNCTION/WITH clause to be used for all language types
configure --enable-debug adds -g (Peter E)
configure --disable-debug removes -g (Peter E)
Allow more complex default expressions (Tom)
First real FOREIGN KEY constraint trigger functionality (Jan)
Add FOREIGN KEY ... MATCH FULL ... ON DELETE CASCADE (Jan)
Add FOREIGN KEY ... MATCH <unspecified> referential actions (Don Baccus)
Allow WHERE restriction on ctid (physical heap location) (Hiroshi)
Move pginterface from contrib to interface directory, rename to pgeasy (Bruce)
Change pgeasy connectdb() parameter ordering (Bruce)
Require SELECT DISTINCT target list to have all ORDER BY columns (Tom)
Add Oracle's COMMENT ON command (Mike Mascari <mascarim@yahoo.com>)
libpq's PQsetNoticeProcessor function now returns previous hook(Peter E)
Prevent PQsetNoticeProcessor from being set to NULL (Peter E)
Make USING in COPY optional (Bruce)
Allow subselects in the target list (Tom)
Allow subselects on the left side of comparison operators (Tom)
New parallel regression test (Jan)
Change backend-side COPY to write files with permissions 644 not 666 (Tom)
Force permissions on PGDATA directory to be secure, even if it exists (Tom)
Added psql LASTOID variable to return last inserted oid (Peter E)
Allow concurrent vacuum and remove pg_vlock vacuum lock file (Tom)
Add permissions check for vacuum (Peter E)
New libpq functions to allow asynchronous connections: PQconnectStart(),
   PQconnectPoll(), PQresetStart(), PQresetPoll(), PQsetenvStart(),
   PQsetenvPoll(), PQsetenvAbort (Ewan Mellor)
New libpq PQsetenv() function (Ewan Mellor)
create/alter user extension (Peter E)
New postmaster.pid and postmaster.opts under $PGDATA (Tatsuo)
New scripts for create/drop user/db (Peter E)
Major psql overhaul (Peter E)
Add const to libpq interface (Peter E)
New libpq function PQoidValue (Peter E)
Show specific non-aggregate causing problem with GROUP BY (Tom)
Make changes to pg_shadow recreate pg_pwd file (Peter E)
Add aggregate(DISTINCT ...) (Tom)
Allow flag to control COPY input/output of NULLs (Peter E)
Make postgres user have a password by default (Peter E)
Add CREATE/ALTER/DROP GROUP (Peter E)
All administration scripts now support --long options (Peter E, Karel)
Vacuumdb script now supports --all option (Peter E)
ecpg new portable FETCH syntax
Add ecpg EXEC SQL IFDEF, EXEC SQL IFNDEF, EXEC SQL ELSE, EXEC SQL ELIF
        and EXEC SQL ENDIF directives
Add pg_ctl script to control backend start-up (Tatsuo)
Add postmaster.opts.default file to store start-up flags (Tatsuo)
Allow --with-mb=SQL_ASCII
Increase maximum number of index keys to 16 (Bruce)
Increase maximum number of function arguments to 16 (Bruce)
Allow configuration of maximum number of index keys and arguments (Bruce)
Allow unprivileged users to change their passwords (Peter E)
Password authentication enabled; required for new users (Peter E)
Disallow dropping a user who owns a database (Peter E)
Change initdb option --with-mb to --enable-multibyte
Add option for initdb to prompts for superuser password (Peter E)
Allow complex type casts like col::numeric(9,2) and col::int2::float8 (Tom)
Updated user interfaces on initdb, initlocation, pg_dump, ipcclean (Peter E)
New pg_char_to_encoding() and pg_encoding_to_char() functions (Tatsuo)
Libpq non-blocking mode (Alfred Perlstein)
Improve conversion of types in casts that don't specify a length
New plperl internal programming language (Mark Hollomon)
Allow COPY IN to read file that do not end with a newline (Tom)
Indicate when long identifiers are truncated (Tom)
Allow aggregates to use type equivalency (Peter E)
Add Oracle's to_char(), to_date(), to_datetime(), to_timestamp(), to_number()
        conversion functions (Karel Zak <zakkr@zf.jcu.cz>)
Add SELECT DISTINCT ON (expr [, expr ...]) targetlist ... (Tom)
Check to be sure ORDER BY is compatible with the DISTINCT operation (Tom)
Add NUMERIC and int8 types to ODBC
Improve EXPLAIN results for Append, Group, Agg, Unique (Tom)
Add ALTER TABLE ... ADD FOREIGN KEY (Stephan Szabo)
Allow SELECT .. FOR UPDATE in PL/pgSQL (Hiroshi)
Enable backward sequential scan even after reaching EOF (Hiroshi)
Add btree indexing of boolean values, >= and <= (Don Baccus)
Print current line number when COPY FROM fails (Massimo)
Recognize POSIX time zone e.g. "PST+8" and "GMT-8" (Thomas)
Add DEC as synonym for DECIMAL (Thomas)
Add SESSION_USER as SQL92 keyword, same as CURRENT_USER (Thomas)
Implement SQL92 column aliases (aka correlation names) (Thomas)
Implement SQL92 join syntax (Thomas)
Make INTERVAL reserved word allowed as a column identifier (Thomas)
Implement REINDEX command (Hiroshi)
Accept ALL in aggregate function SUM(ALL col) (Tom)
Prevent GROUP BY from using column aliases (Tom)
New psql \encoding option (Tatsuo)
Allow PQrequestCancel() to terminate when in waiting-for-lock state (Hiroshi)
Allow negation of a negative number in all cases
Add ecpg descriptors (Christof, Michael)
Allow CREATE VIEW v AS SELECT f1::char(8) FROM tbl
Allow casts with length, like foo::char(8)
New libpq functions PQsetClientEncoding(), PQclientEncoding() (Tatsuo)
Add support for SJIS user defined characters (Tatsuo)
Larger views/rules supported
Make libpq's PQconndefaults() thread-safe (Tom)
Disable // as comment to be ANSI conforming, should use -- (Tom)
Allow column aliases on views CREATE VIEW name (collist)
Fixes for views with subqueries (Tom)
Allow UPDATE table SET fld = (SELECT ...) (Tom)
SET command options no longer require quotes
Update pgaccess to 0.98.6
New SET SEED command
New pg_options.sample file
New SET FSYNC command (Massimo)
Allow pg_descriptions when creating tables
Allow pg_descriptions when creating types, columns, and functions
Allow psql \copy to allow delimiters (Peter E)
Allow psql to print nulls as distinct from "" [null] (Peter E)

Types
-----
Many array fixes (Tom)
Allow bare column names to be subscripted as arrays (Tom)
Improve type casting of int and float constants (Tom)
Cleanups for int8 inputs, range checking, and type conversion (Tom)
Fix for SELECT timespan('21:11:26'::time) (Tom)
netmask('x.x.x.x/0') is 255.255.255.255 instead of 0.0.0.0 (Oleg Sharoiko)
Add btree index on NUMERIC (Jan)
Perl fix for large objects containing NUL characters (Douglas Thomson)
ODBC fix for for large objects (free)
Fix indexing of cidr data type
Fix for Ethernet MAC addresses (macaddr type) comparisons
Fix for date/time types when overflows happened in computations (Tom)
Allow array on int8 (Peter E)
Fix for rounding/overflow of NUMERIC type, like NUMERIC(4,4) (Tom)
Allow NUMERIC arrays
Fix bugs in NUMERIC ceil() and floor() functions (Tom)
Make char_length()/octet_length including trailing blanks (Tom)
Made abstime/reltime use int4 instead of time_t (Peter E)
New lztext data type for compressed text fields
Revise code to handle coercion of int and float constants (Tom)
Start at new code to implement a BIT and BIT VARYING type (Adriaan Joubert)
NUMERIC now accepts scientific notation (Tom)
NUMERIC to int4 rounds (Tom)
Convert float4/8 to NUMERIC properly (Tom)
Allow type conversion with NUMERIC (Thomas)
Make ISO date style (2000-02-16 09:33) the default (Thomas)
Add NATIONAL CHAR [ VARYING ] (Thomas)
Allow NUMERIC round and trunc to accept negative scales (Tom)
New TIME WITH TIME ZONE type (Thomas)
Add MAX()/MIN() on time type (Thomas)
Add abs(), mod(), fac() for int8 (Thomas)
Rename functions to round(), sqrt(), cbrt(), pow() for float8 (Thomas)
Add transcendental math functions (e.g. sin(), acos()) for float8 (Thomas)
Add exp() and ln() for NUMERIC type
Rename NUMERIC power() to pow() (Thomas)
Improved TRANSLATE() function (Edwin Ramirez, Tom)
Allow X=-Y operators  (Tom)
Allow SELECT float8(COUNT(*))/(SELECT COUNT(*) FROM t) FROM t GROUP BY f1; (Tom
)
Allow LOCALE to use indexes in regular expression searches (Tom)
Allow creation of functional indexes to use default types

Performance
-----------
Prevent exponential space consumption with many AND's and OR's (Tom)
Collect attribute selectivity values for system columns (Tom)
Reduce memory usage of aggregates (Tom)
Fix for LIKE optimization to use indexes with multibyte encodings (Tom)
Fix r-tree index optimizer selectivity (Thomas)
Improve optimizer selectivity computations and functions (Tom)
Optimize btree searching for cases where many equal keys exist (Tom)
Enable fast LIKE index processing only if index present (Tom)
Re-use free space on index pages with duplicates (Tom)
Improve hash join processing (Tom)
Prevent descending sort if result is already sorted(Hiroshi)
Allow commuting of index scan query qualifications (Tom)
Prefer index scans in cases where ORDER BY/GROUP BY is required (Tom)
Allocate large memory requests in fix-sized chunks for performance (Tom)
Fix vacuum's performance by reducing memory allocation requests (Tom)
Implement constant-expression simplification (Bernard Frankpitt, Tom)
Use secondary columns to be used to determine start of index scan (Hiroshi)
Prevent quadruple use of disk space when doing internal sorting (Tom)
Faster sorting by calling fewer functions (Tom)
Create system indexes to match all system caches (Bruce, Hiroshi)
Make system caches use system indexes (Bruce)
Make all system indexes unique (Bruce)
Improve pg_statistics management for VACUUM speed improvement (Tom)
Flush backend cache less frequently (Tom, Hiroshi)
COPY now reuses previous memory allocation, improving performance (Tom)
Improve optimization cost estimation (Tom)
Improve optimizer estimate of range queries x > lowbound AND x < highbound (Tom
)
Use DNF instead of CNF where appropriate (Tom, Taral)
Further cleanup for OR-of-AND WHERE-clauses (Tom)
Make use of index in OR clauses (x = 1 AND y = 2) OR (x = 2 AND y = 4) (Tom)
Smarter optimizer computations for random index page access (Tom)
New SET variable to control optimizer costs (Tom)
Optimizer queries based on LIMIT, OFFSET, and EXISTS qualifications (Tom)
Reduce optimizer internal housekeeping of join paths for speedup (Tom)
Major subquery speedup (Tom)
Fewer fsync writes when fsync is not disabled (Tom)
Improved LIKE optimizer estimates (Tom)
Prevent fsync in SELECT-only queries (Vadim)
Make index creation use psort code, because it is now faster (Tom)
Allow creation of sort temp tables > 1 Gig

Source Tree Changes
-------------------
Fix for linux PPC compile
New generic expression-tree-walker subroutine (Tom)
Change form() to varargform() to prevent portability problems
Improved range checking for large integers on Alphas
Clean up #include in /include directory (Bruce)
Add scripts for checking includes (Bruce)
Remove un-needed #include's from *.c files (Bruce)
Change #include's to use <> and "" as appropriate (Bruce)
Enable WIN32 compilation of libpq
Alpha spinlock fix from Uncle George <gatgul@voicenet.com>
Overhaul of optimizer data structures (Tom)
Fix to cygipc library (Yutaka Tanida)
Allow pgsql to work on newer Cygwin snapshots (Dan)
New catalog version number (Tom)
Add Linux ARM
Rename heap_replace to heap_update
Update for QNX (Dr. Andreas Kardos)
New platform-specific regression handling (Tom)
Rename oid8 -> oidvector and int28 -> int2vector (Bruce)
Included all yacc and lex files into the distribution (Peter E.)
Remove lextest, no longer needed (Peter E)
Fix for libpq and psql on Win32 (Magnus)
Internally change datetime and timespan into timestamp and interval (Thomas)
Fix for plpgsql on BSD/OS
Add SQL_ASCII test case to the regression test (Tatsuo)
configure --with-mb now deprecated (Tatsuo)
NT fixes
NetBSD fixes (Johnny C. Lam <lamj@stat.cmu.edu>)
Fixes for Alpha compiles
New multibyte encodings

     _________________________________________________________________
   
                               Release 6.5.3
                                      
     Release date: 1999-10-13
     
   This is basically a cleanup release for 6.5.2. We have added a new
   PgAccess that was missing in 6.5.2, and installed an NT-specific fix.
     _________________________________________________________________
   
                         Migration to version 6.5.3
                                      
   A dump/restore is *not* required for those running 6.5.*.
     _________________________________________________________________
   
                                  Changes
                                      
Updated version of pgaccess 0.98
NT-specific patch
Fix dumping rules on inherited tables

     _________________________________________________________________
   
                               Release 6.5.2
                                      
     Release date: 1999-09-15
     
   This is basically a cleanup release for 6.5.1. We have fixed a variety
   of problems reported by 6.5.1 users.
     _________________________________________________________________
   
                         Migration to version 6.5.2
                                      
   A dump/restore is *not* required for those running 6.5.*.
     _________________________________________________________________
   
                                  Changes
                                      
subselect+CASE fixes(Tom)
Add SHLIB_LINK setting for solaris_i386 and solaris_sparc ports(Daren Sefcik)
Fixes for CASE in WHERE join clauses(Tom)
Fix BTScan abort(Tom)
Repair the check for redundant UNIQUE and PRIMARY KEY indexes(Thomas)
Improve it so that it checks for multicolumn constraints(Thomas)
Fix for Win32 making problem with MB enabled(Hiroki Kataoka)
Allow BSD yacc and bison to compile pl code(Bruce)
Fix SET NAMES working
int8 fixes(Thomas)
Fix vacuum's memory consumption(Hiroshi,Tatsuo)
Reduce the total memory consumption of vacuum(Tom)
Fix for timestamp(datetime)
Rule deparsing bugfixes(Tom)
Fix quoting problems in mkMakefile.tcldefs.sh.in and mkMakefile.tkdefs.sh.in(To
m)
This is to re-use space on index pages freed by vacuum(Vadim)
document -x for pg_dump(Bruce)
Fix for unary operators in rule deparser(Tom)
Comment out FileUnlink of excess segments during mdtruncate()(Tom)
IRIX linking fix from Yu Cao >yucao@falcon.kla-tencor.com<
Repair logic error in LIKE: should not return LIKE_ABORT
   when reach end of pattern before end of text(Tom)
Repair incorrect cleanup of heap memory allocation during transaction abort(Tom
)
Updated version of pgaccess 0.98

     _________________________________________________________________
   
                               Release 6.5.1
                                      
     Release date: 1999-07-15
     
   This is basically a cleanup release for 6.5. We have fixed a variety
   of problems reported by 6.5 users.
     _________________________________________________________________
   
                         Migration to version 6.5.1
                                      
   A dump/restore is *not* required for those running 6.5.
     _________________________________________________________________
   
                                  Changes
                                      
Add NT README file
Portability fixes for linux_ppc, IRIX, linux_alpha, OpenBSD, alpha
Remove QUERY_LIMIT, use SELECT...LIMIT
Fix for EXPLAIN on inheritance(Tom)
Patch to allow vacuum on multisegment tables(Hiroshi)
R-Tree optimizer selectivity fix(Tom)
ACL file descriptor leak fix(Atsushi Ogawa)
New expresssion subtree code(Tom)
Avoid disk writes for read-only transactions(Vadim)
Fix for removal of temp tables if last transaction was aborted(Bruce)
Fix to prevent too large tuple from being created(Bruce)
plpgsql fixes
Allow port numbers 32k - 64k(Bruce)
Add ^ precidence(Bruce)
Rename sort files called pg_temp to pg_sorttemp(Bruce)
Fix for microseconds in time values(Tom)
Tutorial source cleanup
New linux_m68k port
Fix for sorting of NULL's in some cases(Tom)
Shared library dependencies fixed (Tom)
Fixed glitches affecting GROUP BY in subselects(Tom)
Fix some compiler warnings (Tomoaki Nishiyama)
Add Win1250 (Czech) support (Pavel Behal)

     _________________________________________________________________
   
                                Release 6.5
                                      
     Release date: 1999-06-09
     
   This release marks a major step in the development team's mastery of
   the source code we inherited from Berkeley. You will see we are now
   easily adding major features, thanks to the increasing size and
   experience of our world-wide development team.
   
   Here is a brief summary of the more notable changes:
   
   Multiversion concurrency control(MVCC)
          This removes our old table-level locking, and replaces it with
          a locking system that is superior to most commercial database
          systems. In a traditional system, each row that is modified is
          locked until committed, preventing reads by other users. MVCC
          uses the natural multiversion nature of PostgreSQL to allow
          readers to continue reading consistent data during writer
          activity. Writers continue to use the compact pg_log
          transaction system. This is all performed without having to
          allocate a lock for every row like traditional database
          systems. So, basically, we no longer are restricted by simple
          table-level locking; we have something better than row-level
          locking.
          
   Hot backups from pg_dump
          pg_dump takes advantage of the new MVCC features to give a
          consistent database dump/backup while the database stays online
          and available for queries.
          
   Numeric data type
          We now have a true numeric data type, with user-specified
          precision.
          
   Temporary tables
          Temporary tables are guaranteed to have unique names within a
          database session, and are destroyed on session exit.
          
   New SQL features
          We now have CASE, INTERSECT, and EXCEPT statement support. We
          have new LIMIT/OFFSET, SET TRANSACTION ISOLATION LEVEL, SELECT
          ... FOR UPDATE, and an improved LOCK TABLE command.
          
   Speedups
          We continue to speed up PostgreSQL, thanks to the variety of
          talents within our team. We have sped up memory allocation,
          optimization, table joins, and row transfer routines.
          
   Ports
          We continue to expand our port list, this time including
          Windows NT/ix86 and NetBSD/arm32.
          
   Interfaces
          Most interfaces have new versions, and existing functionality
          has been improved.
          
   Documentation
          New and updated material is present throughout the
          documentation. New FAQs have been contributed for SGI and AIX
          platforms. The Tutorial has introductory information on SQL
          from Stefan Simkovics. For the User's Guide, there are
          reference pages covering the postmaster and more utility
          programs, and a new appendix contains details on date/time
          behavior. The Administrator's Guide has a new chapter on
          troubleshooting from Tom Lane. And the Programmer's Guide has a
          description of query processing, also from Stefan, and details
          on obtaining the PostgreSQL source tree via anonymous CVS and
          CVSup.
     _________________________________________________________________
   
                          Migration to version 6.5
                                      
   A dump/restore using pg_dump is required for those wishing to migrate
   data from any previous release of PostgreSQL. pg_upgrade can *not* be
   used to upgrade to this release because the on-disk structure of the
   tables has changed compared to previous releases.
   
   The new Multiversion Concurrency Control (MVCC) features can give
   somewhat different behaviors in multiuser environments. *Read and
   understand the following section to ensure that your existing
   applications will give you the behavior you need.*
     _________________________________________________________________
   
Multiversion Concurrency Control

   Because readers in 6.5 don't lock data, regardless of transaction
   isolation level, data read by one transaction can be overwritten by
   another. In other words, if a row is returned by "SELECT" it doesn't
   mean that this row really exists at the time it is returned (i.e.
   sometime after the statement or transaction began) nor that the row is
   protected from being deleted or updated by concurrent transactions
   before the current transaction does a commit or rollback.
   
   To ensure the actual existence of a row and protect it against
   concurrent updates one must use "SELECT FOR UPDATE" or an appropriate
   "LOCK TABLE" statement. This should be taken into account when porting
   applications from previous releases of PostgreSQL and other
   environments.
   
   Keep the above in mind if you are using "contrib/refint.*" triggers
   for referential integrity. Additional techniques are required now. One
   way is to use "LOCK parent_table IN SHARE ROW EXCLUSIVE MODE" command
   if a transaction is going to update/delete a primary key and use "LOCK
   parent_table IN SHARE MODE" command if a transaction is going to
   update/insert a foreign key.
   
     Note: Note that if you run a transaction in SERIALIZABLE mode then
     you must execute the "LOCK" commands above before execution of any
     DML statement ("SELECT/INSERT/DELETE/UPDATE/FETCH/COPY_TO") in the
     transaction.
     
   These inconveniences will disappear in the future when the ability to
   read dirty (uncommitted) data (regardless of isolation level) and true
   referential integrity will be implemented.
     _________________________________________________________________
   
                                  Changes
                                      
Bug Fixes
---------
Fix text<->float8 and text<->float4 conversion functions(Thomas)
Fix for creating tables with mixed-case constraints(Billy)
Change exp()/pow() behavior to generate error on underflow/overflow(Jan)
Fix bug in pg_dump -z
Memory overrun cleanups(Tatsuo)
Fix for lo_import crash(Tatsuo)
Adjust handling of data type names to suppress double quotes(Thomas)
Use type coercion for matching columns and DEFAULT(Thomas)
Fix deadlock so it only checks once after one second of sleep(Bruce)
Fixes for aggregates and PL/pgsql(Hiroshi)
Fix for subquery crash(Vadim)
Fix for libpq function PQfnumber and case-insensitive names(Bahman Rafatjoo)
Fix for large object write-in-middle, no extra block, memory consumption(Tatsuo
)
Fix for pg_dump -d or -D and  quote special characters in INSERT
Repair serious problems with dynahash(Tom)
Fix INET/CIDR portability problems
Fix problem with selectivity error in ALTER TABLE ADD COLUMN(Bruce)
Fix executor so mergejoin of different column types works(Tom)
Fix for Alpha OR selectivity bug
Fix OR index selectivity problem(Bruce)
Fix so \d shows proper length for char()/varchar()(Ryan)
Fix tutorial code(Clark)
Improve destroyuser checking(Oliver)
Fix for Kerberos(Rodney McDuff)
Fix for dropping database while dirty buffers(Bruce)
Fix so sequence nextval() can be case-sensitive(Bruce)
Fix !!= operator
Drop buffers before destroying database files(Bruce)
Fix case where executor evaluates functions twice(Tatsuo)
Allow sequence nextval actions to be case-sensitive(Bruce)
Fix optimizer indexing not working for negative numbers(Bruce)
Fix for memory leak in executor with fjIsNull
Fix for aggregate memory leaks(Erik Riedel)
Allow username containing a dash GRANT permissions
Cleanup of NULL in inet types
Clean up system table bugs(Tom)
Fix problems of PAGER and \? command(Masaaki Sakaida)
Reduce default multisegment file size limit to 1GB(Peter)
Fix for dumping of CREATE OPERATOR(Tom)
Fix for backward scanning of cursors(Hiroshi Inoue)
Fix for COPY FROM STDIN when using \i(Tom)
Fix for subselect is compared inside an expression(Jan)
Fix handling of error reporting while returning rows(Tom)
Fix problems with reference to array types(Tom,Jan)
Prevent UPDATE SET oid(Jan)
Fix pg_dump so -t option can handle case-sensitive tablenames
Fixes for GROUP BY in special cases(Tom, Jan)
Fix for memory leak in failed queries(Tom)
DEFAULT now supports mixed-case identifiers(Tom)
Fix for multisegment uses of DROP/RENAME table, indexes(Ole Gjerde)
Disable use of pg_dump with both -o and -d options(Bruce)
Allow pg_dump to properly dump GROUP permissions(Bruce)
Fix GROUP BY in INSERT INTO table SELECT * FROM table2(Jan)
Fix for computations in views(Jan)
Fix for aggregates on array indexes(Tom)
Fix for DEFAULT handles single quotes in value requiring too many quotes
Fix security problem with non-super users importing/exporting large objects(Tom
)
Rollback of transaction that creates table cleaned up properly(Tom)
Fix to allow long table and column names to generate proper serial names(Tom)

Enhancements
------------
Add "vacuumdb" utility
Speed up libpq by allocating memory better(Tom)
EXPLAIN all indexes used(Tom)
Implement CASE, COALESCE, NULLIF  expression(Thomas)
New pg_dump table output format(Constantin)
Add string min()/max() functions(Thomas)
Extend new type coercion techniques to aggregates(Thomas)
New moddatetime contrib(Terry)
Update to pgaccess 0.96(Constantin)
Add routines for single-byte "char" type(Thomas)
Improved substr() function(Thomas)
Improved multibyte handling(Tatsuo)
Multiversion concurrency control/MVCC(Vadim)
New Serialized mode(Vadim)
Fix for tables over 2gigs(Peter)
New SET TRANSACTION ISOLATION LEVEL(Vadim)
New LOCK TABLE IN ... MODE(Vadim)
Update ODBC driver(Byron)
New NUMERIC data type(Jan)
New SELECT FOR UPDATE(Vadim)
Handle "NaN" and "Infinity" for input values(Jan)
Improved date/year handling(Thomas)
Improved handling of backend connections(Magnus)
New options ELOG_TIMESTAMPS and USE_SYSLOG options for log files(Massimo)
New TCL_ARRAYS option(Massimo)
New INTERSECT and EXCEPT(Stefan)
New pg_index.indisprimary for primary key tracking(D'Arcy)
New pg_dump option to allow dropping of tables before creation(Brook)
Speedup of row output routines(Tom)
New READ COMMITTED isolation level(Vadim)
New TEMP tables/indexes(Bruce)
Prevent sorting if result is already sorted(Jan)
New memory allocation optimization(Jan)
Allow psql to do \p\g(Bruce)
Allow multiple rule actions(Jan)
Added LIMIT/OFFSET functionality(Jan)
Improve optimizer when joining a large number of tables(Bruce)
New intro to SQL from S. Simkovics' Master's Thesis (Stefan, Thomas)
New intro to backend processing from S. Simkovics' Master's Thesis (Stefan)
Improved int8 support(Ryan Bradetich, Thomas, Tom)
New routines to convert between int8 and text/varchar types(Thomas)
New bushy plans, where meta-tables are joined(Bruce)
Enable right-hand queries by default(Bruce)
Allow reliable maximum number of backends to be set at configure time
      (--with-maxbackends and postmaster switch (-N backends))(Tom)
GEQO default now 10 tables because of optimizer speedups(Tom)
Allow NULL=Var for MS-SQL portability(Michael, Bruce)
Modify contrib check_primary_key() so either "automatic" or "dependent"(Anand)
Allow psql \d on a view show query(Ryan)
Speedup for LIKE(Bruce)
Ecpg fixes/features, see src/interfaces/ecpg/ChangeLog file(Michael)
JDBC fixes/features, see src/interfaces/jdbc/CHANGELOG(Peter)
Make % operator have precedence like /(Bruce)
Add new postgres -O option to allow system table structure changes(Bruce)
Update contrib/pginterface/findoidjoins script(Tom)
Major speedup in vacuum of deleted rows with indexes(Vadim)
Allow non-SQL functions to run different versions based on arguments(Tom)
Add -E option that shows actual queries sent by \dt and friends(Masaaki Sakaida
)
Add version number in start-up banners for psql(Masaaki Sakaida)
New contrib/vacuumlo removes large objects not referenced(Peter)
New initialization for table sizes so non-vacuumed tables perform better(Tom)
Improve error messages when a connection is rejected(Tom)
Support for arrays of char() and varchar() fields(Massimo)
Overhaul of hash code to increase reliability and performance(Tom)
Update to PyGreSQL 2.4(D'Arcy)
Changed debug options so -d4 and -d5 produce different node displays(Jan)
New pg_options: pretty_plan, pretty_parse, pretty_rewritten(Jan)
Better optimization statistics for system table access(Tom)
Better handling of non-default block sizes(Massimo)
Improve GEQO optimizer memory consumption(Tom)
UNION now suppports ORDER BY of columns not in target list(Jan)
Major libpq++ improvements(Vince Vielhaber)
pg_dump now uses -z(ACL's) as default(Bruce)
backend cache, memory speedups(Tom)
have pg_dump do everything in one snapshot transaction(Vadim)
fix for large object memory leakage, fix for pg_dumping(Tom)
INET type now respects netmask for comparisons
Make VACUUM ANALYZE only use a readlock(Vadim)
Allow VIEWs on UNIONS(Jan)
pg_dump now can generate consistent snapshots on active databases(Vadim)

Source Tree Changes
-------------------
Improve port matching(Tom)
Portability fixes for SunOS
Add NT/Win32 backend port and enable dynamic loading(Magnus and Daniel Horak)
New port to Cobalt Qube(Mips) running Linux(Tatsuo)
Port to NetBSD/m68k(Mr. Mutsuki Nakajima)
Port to NetBSD/sun3(Mr. Mutsuki Nakajima)
Port to NetBSD/macppc(Toshimi Aoki)
Fix for tcl/tk configuration(Vince)
Removed CURRENT keyword for rule queries(Jan)
NT dynamic loading now works(Daniel Horak)
Add ARM32 support(Andrew McMurry)
Better support for HP-UX 11 and UnixWare
Improve file handling to be more uniform, prevent file descriptor leak(Tom)
New install commands for plpgsql(Jan)

     _________________________________________________________________
   
                               Release 6.4.2
                                      
     Release date: 1998-12-20
     
   The 6.4.1 release was improperly packaged. This also has one
   additional bug fix.
     _________________________________________________________________
   
                         Migration to version 6.4.2
                                      
   A dump/restore is *not* required for those running 6.4.*.
     _________________________________________________________________
   
                                  Changes
                                      
Fix for datetime constant problem on some platforms(Thomas)
     _________________________________________________________________
   
                               Release 6.4.1
                                      
     Release date: 1998-12-18
     
   This is basically a cleanup release for 6.4. We have fixed a variety
   of problems reported by 6.4 users.
     _________________________________________________________________
   
                         Migration to version 6.4.1
                                      
   A dump/restore is *not* required for those running 6.4.
     _________________________________________________________________
   
                                  Changes
                                      
Add pg_dump -N flag to force double quotes around identifiers.  This is
        the default(Thomas)
Fix for NOT in where clause causing crash(Bruce)
EXPLAIN VERBOSE coredump fix(Vadim)
Fix shared-library problems on Linux
Fix test for table existance to allow mixed-case and whitespace in
        the table name(Thomas)
Fix a couple of pg_dump bugs
Configure matches template/.similar entries better(Tom)
Change builtin function names from SPI_* to spi_*
OR WHERE clause fix(Vadim)
Fixes for mixed-case table names(Billy)
contrib/linux/postgres.init.csh/sh fix(Thomas)
libpq memory overrun fix
SunOS fixes(Tom)
Change exp() behavior to generate error on underflow(Thomas)
pg_dump fixes for memory leak, inheritance constraints, layout change
update pgaccess to 0.93
Fix prototype for 64-bit platforms
Multibyte fixes(Tatsuo)
New ecpg man page
Fix memory overruns(Tatsuo)
Fix for lo_import() crash(Bruce)
Better search for install program(Tom)
Timezone fixes(Tom)
HP-UX fixes(Tom)
Use implicit type coercion for matching DEFAULT values(Thomas)
Add routines to help with single-byte (internal) character type(Thomas)
Compilation of libpq for Win32 fixes(Magnus)
Upgrade to PyGreSQL 2.2(D'Arcy)
     _________________________________________________________________
   
                                Release 6.4
                                      
     Release date: 1998-10-30
     
   There are *many* new features and improvements in this release. Thanks
   to our developers and maintainers, nearly every aspect of the system
   has received some attention since the previous release. Here is a
   brief, incomplete summary:
   
     * Views and rules are now functional thanks to extensive new code in
       the rewrite rules system from Jan Wieck. He also wrote a chapter
       on it for the Programmer's Guide.
     * Jan also contributed a second procedural language, PL/pgSQL, to go
       with the original PL/pgTCL procedural language he contributed last
       release.
     * We have optional multiple-byte character set support from Tatsuo
       Ishii to complement our existing locale support.
     * Client/server communications has been cleaned up, with better
       support for asynchronous messages and interrupts thanks to Tom
       Lane.
     * The parser will now perform automatic type coercion to match
       arguments to available operators and functions, and to match
       columns and expressions with target columns. This uses a generic
       mechanism which supports the type extensibility features of
       PostgreSQL. There is a new chapter in the User's Guide which
       covers this topic.
     * Three new data types have been added. Two types, inet and cidr,
       support various forms of IP network, subnet, and machine
       addressing. There is now an 8-byte integer type available on some
       platforms. See the chapter on data types in the User's Guide for
       details. A fourth type, serial, is now supported by the parser as
       an amalgam of the int4 type, a sequence, and a unique index.
     * Several more SQL92-compatible syntax features have been added,
       including "INSERT DEFAULT VALUES"
     * The automatic configuration and installation system has received
       some attention, and should be more robust for more platforms than
       it has ever been.
     _________________________________________________________________
   
                          Migration to version 6.4
                                      
   A dump/restore using pg_dump or pg_dumpall is required for those
   wishing to migrate data from any previous release of PostgreSQL.
     _________________________________________________________________
   
                                  Changes
                                      
Bug Fixes
---------
Fix for a tiny memory leak in PQsetdb/PQfinish(Bryan)
Remove char2-16 data types, use char/varchar(Darren)
Pqfn not handles a NOTICE message(Anders)
Reduced busywaiting overhead for spinlocks with many backends (dg)
Stuck spinlock detection (dg)
Fix up "ISO-style" timespan decoding and encoding(Thomas)
Fix problem with table drop after rollback of transaction(Vadim)
Change error message and remove non-functional update message(Vadim)
Fix for COPY array checking
Fix for SELECT 1 UNION SELECT NULL
Fix for buffer leaks in large object calls(Pascal)
Change owner from oid to int4 type(Bruce)
Fix a bug in the oracle compatibility functions btrim() ltrim() and rtrim()
Fix for shared invalidation cache overflow(Massimo)
Prevent file descriptor leaks in failed COPY's(Bruce)
Fix memory leak in libpgtcl's pg_select(Constantin)
Fix problems with username/passwords over 8 characters(Tom)
Fix problems with handling of asynchronous NOTIFY in backend(Tom)
Fix of many bad system table entries(Tom)

Enhancements
------------
Upgrade ecpg and ecpglib,see src/interfaces/ecpc/ChangeLog(Michael)
Show the index used in an EXPLAIN(Zeugswetter)
EXPLAIN  invokes  rule system and shows plan(s) for rewritten queries(Jan)
Multibyte awareness of many data types and functions, via configure(Tatsuo)
New configure --with-mb option(Tatsuo)
New initdb --pgencoding option(Tatsuo)
New createdb -E multibyte option(Tatsuo)
Select version(); now returns PostgreSQL version(Jeroen)
Libpq now allows asynchronous clients(Tom)
Allow cancel from client of backend query(Tom)
Psql now cancels query with Control-C(Tom)
Libpq users need not issue dummy queries to get NOTIFY messages(Tom)
NOTIFY now sends sender's PID, so you can tell whether it was your own(Tom)
PGresult struct now includes associated error message, if any(Tom)
Define "tz_hour" and "tz_minute" arguments to date_part()(Thomas)
Add routines to convert between varchar and bpchar(Thomas)
Add routines to allow sizing of varchar and bpchar into target columns(Thomas)
Add bit flags to support timezonehour and minute in data retrieval(Thomas)
Allow more variations on valid floating point numbers (e.g. ".1", "1e6")(Thomas
)
Fixes for unary minus parsing with leading spaces(Thomas)
Implement TIMEZONE_HOUR, TIMEZONE_MINUTE per SQL92 specs(Thomas)
Check for and properly ignore FOREIGN KEY column constraints(Thomas)
Define USER as synonym for CURRENT_USER per SQL92 specs(Thomas)
Enable HAVING clause but no fixes elsewhere yet.
Make "char" type a synonym for "char(1)" (actually implemented as bpchar)(Thoma
s)
Save string type if specified for DEFAULT clause handling(Thomas)
Coerce operations involving different data types(Thomas)
Allow some index use for columns of different types(Thomas)
Add capabilities for automatic type conversion(Thomas)
Cleanups for large objects, so file is truncated on open(Peter)
Readline cleanups(Tom)
Allow psql  \f \ to make spaces as delimiter(Bruce)
Pass pg_attribute.atttypmod to the frontend for column field lengths(Tom,Bruce)
Msql compatibility library in /contrib(Aldrin)
Remove the requirement that ORDER/GROUP BY clause identifiers be
included in the target list(David)
Convert columns to match columns in UNION clauses(Thomas)