postgresql/doc/TODO

TODO list for PostgreSQL
========================
Last updated:		Fri Nov  6 22:17:33 EST 1998

Current maintainer:	Bruce Momjian (maillist@candle.pha.pa.us)

The most recent version of this document can be viewed at
the PostgreSQL WWW site, http://www.postgreSQL.org.

THE CHANGES FOR 6.4 APPEAR AT THE END OF THIS DOCUMENT

A dash(-) marks changes to be in the next release.

Developers who have claimed items are:
-------------------------------------
	* Billy is Billy G. Allie <Bill.Allie@mug.org>
	* Brook is Brook Milligan <brook@trillium.NMSU.Edu>
	* Bruce is Bruce Momjian<maillist@candle.pha.pa.us>
	* Bryan is Bryan Henderson<bryanh@giraffe.netgate.net>
	* D'Arcy is D'Arcy J.M. Cain <darcy@druid.net>
	* Dan is Dan McGuirk <mcguirk@indirect.com>
	* Darren is Darren King <darrenk@insightdist.com>
	* David is David Hartwig <daveh@insightdist.com>
	* Edmund is Edmund Mergl <E.Mergl@bawue.de>
	* Goran is Goran Thyni <goran@bildbasen.se>
	* Henry is Henry B. Hotz <hotz@jpl.nasa.gov>
	* Jan is Jan Wieck <wieck@sapserv.debis.de>
	* Jun is Jun Kuwamura <juk@rccm.co.jp>
	* Maarten is Maarten Boekhold <maartenb@dutepp0.et.tudelft.nl>
 	* Marc is Marc Fournier <scrappy@hub.org>
 	* Martin is Martin S. Utesch <utesch@aut.tu-freiberg.de>
	* Massimo Dal Zotto <dz@cs.unitn.it>
	* Michael is Michael Meskes <meskes@debian.org>
	* Oleg is Oleg Bartunov <oleg@sai.msu.su>
	* Paul is Paul M. Aoki <aoki@CS.Berkeley.EDU>
	* Peter is Peter T Mount <peter@retep.org.uk>
	* Phil is Phil Thompson <phil@river-bank.demon.co.uk>
	* Ryan is Ryan Kirkpatrick <rkirkpat@nag.cs.colorado.edu>
	* Soo-Ho Ok <shok@detc.dongeui-tc.ac.kr>
	* Stefan Simkovics <ssimkovi@rainbow.studorg.tuwien.ac.at>
	* Sven is Sven Verdoolaege <skimo@breughel.ufsia.ac.be>
	* Tatsuo is Tatsuo Ishii <t-ishii@sra.co.jp>
	* Tom is Tom Lane <tgl@sss.pgh.pa.us>
	* Thomas is Thomas Lockhart <tgl@mythos.jpl.nasa.gov>
	* TomH is Tom I Helbekkmo <tih@Hamartun.Priv.NO>
	* Vadim is "Vadim B. Mikheev" <vadim@sable.krasnoyarsk.su>

Additional 6.4 developers include:
---------------------------------
	* Jun Kuwamura <juk@rccm.co.jp>
	* Zeugswetter Andreas SARZ <Andreas.Zeugswetter@telecom.at>
	* Soonmyung. Hong <hong@lunaris.hanmesoft.co.kr>
	* Anders Hammarquist <iko@netg.se>
	* Jeroen van Vianen <jeroenv@design.nl>
	* Aldrin L. <aldrin@americasnet.com>
	* Pascal ANDRE <andre@via.ecp.fr>
	* Magnus Hagander <mha@edu.sollentuna.se>
	* Robert Bruccoleri <bruc@pluto.njcc.com>
	* Paul A Vixie <paul@vix.com>
	* Jacek Lasecki <jacek@sound.eti.pg.gda.pl>

RELIABILITY
-----------
* Overhaul mdmgr/smgr to fix double unlinking and double opens, cleanup
* Overhaul bufmgr/lockmgr/transaction manager
* Remove EXTEND?
* Can lo_export()/lo_import() read/write anywhere, causing a security problem?
* Tables that start with xinv confused to be large objects
* Two and three dimmensional arrays display improperly, missing {}
* GROUP BY in INSERT INTO table SELECT * FROM table2 fails
* Prevent auto-table reference, like SELECT table.col WHERE col = 3 (?)
* SELECT * FROM table WHERE int4_column = '1' fails
* SELECT a[1] FROM test fails, it needs test.a[1]
* UPDATE table SET table.value = 3 fails
* User who can create databases can modify pg_database table
* optimizer memory exhaustion with many OR's
* elog() does not free all its memory(Jan)
* views on subselects fail
* disallow inherited columns with the same name as new columns
* recover or force failure when disk space is exhausted
* default char() value not to full length crashes server on some OS's
* allow UPDATE using aggregate to affect all rows, not just one
* computations in views fail:
	create view test as select usesysid * usesysid from pg_shadow;
* views containing aggregates sometimes fail(Jan)

ENHANCEMENTS
------------
* Replace table-level locking with row or page-level locking(Vadim)
* Add SERIAL type
* Transaction log, so re-do log can be on a separate disk
* Allow transaction commits with rollback with no-fsync performance
* More access control over who can create tables and access the database
* Add full ANSI SQL capabilities
	* add OUTER joins, left and right (Thomas)
	* add INTERSECTS, SUBTRACTS(Stephan)
	* add temporary tables
	* add sql3 recursive unions
	* add the concept of dataspaces
	* add DECIMAL, NUMERIC, DOUBLE PRECISION, BIT, BIT VARYING
 	* NCHAR (as distinguished from ordinary varchar),
	* DOMAIN capability
* Allow compression of large fields or a compressed field type
* Fix the rules system(Jan,Soo-Ho)
	* add CONSTRAINT
* Full set of text operations and functions
	* word searches, concat,max() on text, char
* Large objects
	* Fix large object mapping scheme, own reltype(Peter)
	* Allow large text type to use large objects(Peter)
	* not to stuff everything as files in a single directory
	* Fix large object memory leaks
	* delete orphaned large objects
* Better interface for adding to pg_group
* Make MONEY/DECIMAL have a defined precision
* Fix tables >2G, or report error when 2G size reached
	(fix lseek()/off_t, mdextend()/RELSEG_SIZE)
* Add REGEX internationalization
* allow row re-use without vacuum, maybe?(Vadim)
* Add word index for text fields, maybe with trigrams, i.e.:
    * ' (cat | dog) & ! fox ' meaning text has cat aor dog, but not fox
* Populate backend status area and write program to dump status data
* Add ALTER TABLE DROP COLUMN feature
* Allow INSERT INTO ... SELECT to convert column types
* Add syslog functionality(Marc)
* Add STDDEV/VARIANCE() function for standard deviation computation/variance
* add UNIQUE capability to non-btree indexes
* make number of backends a config parameter, storage/sinvaladt.h:MaxBackendId
* certain indexes will not shrink, i.e. oid indexes with many inserts
* make NULL's come out at the beginning or end depending on the ORDER BY direction
* change the library/backend interface to use network byte order
* Restore unused oid's on backend exit if no one else has gotten oids
* remove non-standard types from the system, and make them loadable
* have UPDATE/DELETE clean out indexes
* allow WHERE restriction on ctid
* allow pg_descriptions when creating types, tables, columns, and functions
* Fix compile and security of Kerberos/GSSAPI code
* Allow psql to print nulls as distinct from ""(?)
* Allow variable casts with BETWEEN 'today'::asbtime AND 'today'::abstime
* Allow INSERT INTO ... SELECT ... FROM view to work
* Make VACUUM on database not lock pg_class
* Make VACUUM ANALYZE only use a readlock
* Allow cursors to be DECLAREd/OPENed/CLOSEed outside transactions
* Allow installation data block size and max tuple size configuration(Darren)
* Allow views on a UNION
* Allow DISTINCT on view
* Allow views of aggregate columns
* Allow variable block sizes(Darren)
* System tables are now more update-able from SQL(Jan)
* New pg_shadow file, pg_user is now a view of pg_shadow(Jan)
* Allow flag to control COPY input/output of NULLs
* Allow CLUSTER on all tables at once, and improve CLUSTER
* Change all references of Postgres to PostgreSQL, including binary names
* Add ELOG_TIMESTAMPS to elog()(?)
* Change LOCK tablename to LOCK TABLE tablename(?)
* Allow max tuple length to be changed(Darren)
* Have psql with no database name not connect to username as default(?)
* Allow subqueries in target list
* Granting permissions to another user looses permissions for the owner
* Allow queries across multiple databases
* Add replication of distributed databases
* Allow table destruction/alter to be rolled back
* Add pg_attribute.atttypmod/Resdom->restypmod to PGresult structure
* Generate error on CREATE OPERATOR of ~~, ~ and and ~*
* Allow constraint NULL just as we honor NOT NULL
* Add version number in startup banners for psql and postmaster
* Restructure storing of GRANT permission information to allow +-=
* allow psql \copy to allow delimiters
* allow international error message support and add error codes
* allow ORDER BY a function(David)
* allow usernames with dashes(GRANT fails)
* add a function to return the last inserted oid, for use in psql scripts
* allow creation of functional indexes to use default types
* put sort files, large objects in their on directory
* CREATE VIEW myview (name) AS SELECT lname FROM wages fails
* do autocommit so always in a transaction block
* add SIMILAR TO to allow character classes, 'pg_[a-c]%'
* allow function isnull(val,'string') to return string if value is null
* multi-verion concurrency control(Vadim)
* improve reporting of syntax errors by showing location of error in query
* allow chaining of pages to allow >8k tuples
* no min/max for oid type
* remove un-needed conversion functions
* redesign the function call interface to handle NULLs better(Jan)

PERFORMANCE
-----------
* Use indexes in ORDER BY for restrictive data sets, min(), max()
* Allow LIMIT ability on single-table queries that have no ORDER BY or 
	a matching index
* Pull requested data directly from indexes, bypassing heap data
* Prevent psort() usage when query already using index matching ORDER BY
* Optimizing disjunctive queries
* Fix bushy-plans
* Prevent fsync in SELECT-only queries
* Cache most recent query plan(s?)
* Shared catalog cache, reduce lseek()'s by caching table size in shared area
* Allow compression of log and meta data
* Add FILLFACTOR to index creation
* update pg_statistic table to remove operator column
* make index creation use psort code, because it is now faster(Vadim)
* remove fork()/exec() of backend and make it just fork()
* Add base table name to \d index
* Allow char() not to use variable-sized header to reduce disk size
* Do async I/O to do better read-ahead of data
* Fix optmizer problem with self-table joins
* Fix memory exhaustion when using many OR's
* Use spin locks only on multi-CPU systems, yield CPU instead
* Get faster regex() code from Henry Spencer <henry@zoo.utoronto.ca>
	when it is available
* use mmap() rather than SYSV shared memory(?)
* use index to restrict rows returned by multi-key index when used with
	non-consecutive keys or OR clauses, so fewer heap accesses
* use index with constants on functions

DOCUMENTATION
-------------
* Update usermanual source(many)
* added features used in grammer but not in docs, like :: and CAST
* Add keyword list to documentation, already in /tools
* Add 'man pgsql' to show all manual page names
* Add use of 'const' for varibles in source tree


=============================================================================

CHANGES IN THE 6.4 RELEASE
--------------------------

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)
Multi-byte 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)(Thomas)
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)
Remove fork()/exec() and only do fork()(Bruce)
Jdbc cleanups(Peter)
Show backend status on ps command line(only works on some platforms)(Bruce)
Pg_hba.conf now has a sameuser option in the database field
Make lo_unlink take oid param, not int4
New DISABLE_COMPLEX_MACRO for compilers that can't handle our macros(Bruce)
Libpgtcl now handles NOTIFY as a Tcl event, need not send dummy queries(Tom)
libpgtcl cleanups(Tom)
Add -error option to libpgtcl's pg_result command(Tom)
New locale patch, see docs/README/locale(Oleg)
Fix for pg_dump so CONSTRAINT and CHECK syntax is correct(ccb)
New contrib/lo code for large object orphan removal(Peter)
New psql command "SET CLIENT_ENCODING TO 'encoding'" for multi-bytes
feature, see /doc/README.mb(Tatsuo)
/contrib/noupdate code to revoke update permission on a column
Libpq can now be compiled on win32(Magnus)
Add PQsetdbLogin() in libpq
New 8-byte integer type, checked by configure for OS support(Thomas)
Better support for quoted table/column names(Thomas)
Surround table and column names with double-quotes in pg_dump(Thomas)
PQreset() now works with passwords(Tom)
Handle case of GROUP BY target list column number out of range(David)
Allow UNION in subselects
Add auto-size to screen to \d? commands(Bruce)
Use UNION to show all \d? results in one query(Bruce)
Add \d? field search feature(Bruce)
Pg_dump issues fewer \connect requests(Tom)
Make pg_dump -z flag work better, document it in manual page(Tom)
Add HAVING clause with full support for subselects and unions(Stephan)
Full text indexing routines in contrib/fulltextindex(Maarten)
Transaction ids now stored in shared memory(Vadim)
New PGCLIENTENCODING when issuing COPY command(Tatsuo)
Support for SQL92 syntax "SET NAMES"(Tatsuo)
Support for LATIN2-5(Tatsuo)
Add UNICODE regression test case(Tatsuo)
Lock manager cleanup, new locking modes for LLL(Vadim)
Allow index use with OR clauses(Bruce)
Allows "SELECT NULL ORDER BY 1;"
Explain VERBOSE prints the plan, and now pretty-prints the plan to
the postmaster log file(Bruce)
Add Indices display to \d command(Bruce)
Allow GROUP BY on functions(David)
New pg_class.relkind for large objects(Bruce)
New way to send libpq NOTICE messages to a different location(Tom)
New \w write command to psql(Bruce)
New /contrib/findoidjoins scans oid columns to find join relationships(Bruce)
Allow binary-compatible indices to be considered when checking for valid
indices for restriction clauses containing a constant(Thomas)
New ISBN/ISSN code in /contrib/isbn_issn
Allow NOT LIKE, IN, NOT IN, BETWEEN, and NOT BETWEEN constraint(Thomas)
New rewrite system fixes many problems with rules and views(Jan)
	* Rules on relations work
	* Event qualifications on insert/update/delete work
	* New OLD variable to reference CURRENT, CURRENT will be remove in future
	* Update rules can reference NEW and OLD in rule qualifications/actions
	* Insert/update/delete rules on views work
	* Multiple rule actions are now supported, surrounded by parentheses
	* Regular users can create views/rules on tables they have RULE permits
	* Rules and views inherit the permissions on the creator
	* No rules at the column level
	* No UPDATE NEW/OLD rules
	* New pg_tables, pg_indexes, pg_rules and pg_views system views
	* Only a single action on SELECT rules
	* Total rewrite overhaul, perhaps for 6.5
	* handle subselects
	* handle aggregates on views
	* handle insert into select from view works
System indexes are now multi-key(Bruce)
Oidint2, oidint4, and oidname types are removed(Bruce)
Use system cache for more system table lookups(Bruce)
New backend programming language PL/pgSQL in backend/pl(Jan)
New SERIAL data type, auto-creates sequence/index(Thomas)
Enable assert checking without a recompile(Massimo)
User lock enhancements(Massimo)
New setval() command to set sequence value(Massimo)
Auto-remove unix socket file on startup if no postmaster running(Massimo)
Conditional trace package(Massimo)
New UNLISTEN command(Massimo)
Psql and libpq now compile under win32 using win32.mak(Magnus)
Lo_read no longer stores trailing NULL(Bruce)
Identifiers are now truncated to 31 characters internally(Bruce)
Createuser options now availble on the command line
Code for 64-bit integer supported added, configure tested, int8 type(Thomas)
Prevent file descriptor leaf from failed COPY(Bruce)
New pg_upgrade command(Bruce)
Updated /contrib directories(Massimo)
New CREATE TABLE DEFAULT VALUES statement available(Thomas)
New INSERT INTO TABLE DEFAULT VALUES statement available(Thomas)
New DECLARE and FETCH feature(Thomas)
libpq's internal structures now not exported(Tom)
Allow up to 8 key indexes(Bruce)
Remove ARCHIVE keyword, that is no longer used(Thomas)
pg_dump -n flag to supress quotes around indentifiers
disable system columns for views(Jan)
new INET and CIDR types for network addresses(TomH, Paul)
no more double quotes in psql output
pg_dump now dumps views(Terry)
new SET QUERY_LIMIT(Tatsuo,Jan)

Source Tree Changes
-------------------
/contrib cleanup(Jun)
Inline some small functions called for every row(Bruce)
Alpha/linux fixes
Hp/UX cleanups(Tom)
Multi-byte regression tests(Soonmyung.)
Remove --disabled options from configure
Define PGDOC to use POSTGRESDIR by default
Make regression optional
Remove extra braces code to pgindent(Bruce)
Add bsdi shared library support(Bruce)
New --without-CXX support configure option(Brook)
New FAQ_CVS
Update backend flowchart in tools/backend(Bruce)
Change atttypmod from int16 to int32(Bruce, Tom)
Getrusage() fix for platforms that do not have it(Tom)
Add PQconnectdb, PGUSER, PGPASSWORD to libpq man page
NS32K platform fixes(Phil Nelson, John Buller)
Sco 7/UnixWare 2.x fixes(Billy,others)
Sparc/Solaris 2.5 fixes(Ryan)
Pgbuiltin.3 is obsolete, move to doc files(Thomas)
Even more documention(Thomas)
Nextstep support(Jacek)
Aix support(David)
pginterface manual page(Bruce)
shared libraries all have version numbers
merged all OS-specific shared library defines into one file
smarter TCL/TK configuration checking(Billy)
smarter perl configuration(Brook)
configure uses supplied install-sh if no install script found(Tom)
new Makefile.shlib for shared library configuration(Tom)