postgresql/doc/TODO

====================================================
TODO list (FAQ) for PostgreSQL
====================================================
last updated:		Tue Jun  3 16:30:57 EDT 1997

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 6.1 APPEAR AT THE END OF THIS DOCUMENT

Developers who have claimed items are:
	Bruce is Bruce Momjian<maillist@candle.pha.pa.us>
	Bryan is Bryan Henderson<bryanh@giraffe.netgate.net>
	Dan is Dan McGuirk <mcguirk@indirect.com>
	Daniel is Daniel Kalchev <daniel@digsys.bg>
	Darren is Darren King <darrenk@insightdist.com>
	Edmund is Edmund Mergl <E.Mergl@bawue.de>
	Erich Stamberger <eberger@gewi.kfunigraz.ac.at>
	Igor is Igor <igor@sba.miami.edu>
	Jun is Jun Kuwamura <juk@rccm.co.jp>
	Kurt is "Kurt J. Lidl" <lidl@va.pubnix.com>
 	Martin is Martin S. Utesch <utesch@aut.tu-freiberg.de>
	Oleg is Oleg Bartunov <oleg@sai.msu.su>
	Paul is Paul M. Aoki <aoki@CS.Berkeley.EDU>
	Raymond is Raymond Toy <toy@rtp.ericsson.se>
	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>
	Thomas is Thomas Lockhart <tgl@mythos.jpl.nasa.gov>
	Vadim is "Vadim B. Mikheev" <vadim@sable.krasnoyarsk.su>
	Vivek is Vivek Khera <khera@kci.kciLink.com>

RELIABILITY
-----------
-Overhaul mdmgr/smgr to fix double unlinking and double opens, cleanup(Erich)
-Overhaul bufmgr/lockmgr/transaction manager(Vadim)
remove -S (stable memory) option or fix memory manager
Fix CLUSTER
Fix all NULL features
	allow psql to print nulls meaningfully
Fix compile and security of Kerberos/GSSAPI code (Daniel Kalchev?)
Dropping a table twice causes corruption, drop/create not rollback-able
SELECT on two tables where zero or one table in WHERE and target
 	clause returns no rows
COUNT on VIEW always returns zero (maybe because there is no oid for views?)
CREATE VIEW requires super-user priviledge
SELECT a[1] FROM test fails, it needs test.a[1]
INSERT INTO ... SELECT DISTINCT ... generates error on DISTINCT
pg_database.datdba is oid, should be int4
can lo_export()/lo_import() read/write anywhere, causing a security problem?
Fix UPDATE key_table SET keyval=max(reftab.NUM)+1 WHERE tblname='reftab'
SELECT COUNT(*) FROM TAB1, TAB2 fails
Tables that start with xinv confused to be large objects

ENHANCEMENTS
------------
Add full ANSI SQL capabilities (Stefan)
	add subselects, possibility using temporary SQL functions
	Implement HAVING clause
	Implement EXISTS qualifier
	column constraints (using rules), PRIMARY KEY during table creation
	add DEFAULT, RESTRAINT, and CHECK capabilities
	report "Not implemented" if valid syntax is supplied
	add NOT NULL to CREATE statement
	add OUTER joins, left and right
	make VIEWs updateable where possible
	add UNIONS, INTERSECTS, SUBTRACTS
	add temporary tables
	add assertions
	add domains
	add sql3 recursive unions
	add the concept of dataspaces
	allow conversion type casts on SELECT target fields
Allow compression of large fields or a compressed field type
Fix the rules system(Jan?,Soo-Ho)
	robust
	making INSTEAD rules work
	add CONSTRAINT
Full set of text operations and functions
	word searches, concat,max() on text, char
Replace table-level locking with row or page-level locking(Vadim)
Large objects
	overwriting blocks has problems
	there are other problems, too.
	Fix large object mapping scheme
	not to stuff everything as files in a single directory
Better interface for adding to pg_group
Make MONEY/DECIMAL have a defined precision
Add support for tables >2G, or test current version
Incorporate the PERL PG95 interface library into source tree(Edmund)
Threaded version of the server or libpq
Allow libpq to cancel query requests
Add REGEX internationalization
Add other language types for built-in functions
	expand to allow tcl, perl, java,
	generalize the function manager switch to pass 
		function sources to interpreter engines.
remove time-travel feature(Vadim)
reduce system column overhead(Vadmin)
remove pg_time table(Vadim)
allow row re-use without vacuum, maybe?(Vadim)
can't vacuum large objects
can't reduce index file size with vacuum
Remove restriction that ORDER BY field must be in SELECT list(?)
Allow queries about owner of datbases, tables like:
        SELECT u.usesysid FROM postgres.pg_user u;
Add word index for text fields, maybe with trigrams, i.e.:
    ' (cat | dog) & ! fox ' meaning text has cat or dog, but not fox
Allow readline-type or editor command editing of multi-line SQL commands
Populate backend status area and write program to dump status data
Add ALTER TABLE DROP COLUMN feature
Remove stale files upon startup(Vivek)
Add command to show privileges
Allow INSERT INTO ... SELECT to convert column types
Add syslog functionality
Improve optimizer plan choice(Darren)
Add STDDEV/VARIANCE() function for standard deviation computation/variance
Add table/column/function discription table indexed by oid
add pg_type attribute to identify types that need length (bpchar, varchar)
add UNIQUE capability to non-btree indexes
make pg_dumpall preserve table ownership, not just database ownership
make large objects have their own reltype
make number of backends a config parameter, storage/sinvaladt.h:MaxBackendId
certain indexes will not shrink, i.e. oid indexes with many inserts

PERFORMANCE
-----------
Optimizing disjunctive queries
Fix bushy-plans (Martin)
Other optimizer bugs
Is fsync use optimized?
Multi-representational types, a la Illustra. For example, have a
       text type that is stored in-tuple when less than 8K and in large
       objects, when greater than 8K.
Use indexes in ORDER BY
Profile engine in INSERT's and other operations
Cache most recent query plan(s?)
Allow compression of log and meta data
Allow LIKE/wildcard matches to use indexes if the wildcard character is not first
Add FILLFACTOR to index creation
Allow indexes to be used with OR clauses(Vadim)
Change pg_attribute.attnvals name to attdispursion and change type float4
	update pg_statistic table to remove operator column

DOCUMENTATION
-------------
Update usermanual source(many)
remove time-travel in documentation(Bruce)
added features used in grammer but not in docs, like :: and CAST
add DECLARE manual page

PORTABILITY
-----------
 

---------------------------------------------------------------------------

                      CHANGES IN THE 6.1 RELEASE

Bug Fixes
---------
packet length checking in library routines
lock manager priority patch
check for under/over flow of float8(Bruce)
multi-table join fix(Vadim)
SIGPIPE crash fix(Darren)
large object fixes(Sven)
allow btree indexes to handle NULLs(Vadim)
timezone fixes(D'Arcy)
select SUM(x) can return NULL on no rows(Thomas)
internal optimizer, executor bug fixes(Vadim)
fix problem where inner loop in < or <= has no rows(Vadim)
prevent re-commuting join index clauses(Vadim)
fix join clauses for multiple tables(Vadim)
fix hash, hashjoin for arrays(Vadim)
fix btree for abstime type(Vadim)
large object fixes(Raymond)
fix buffer leak in hash indices (Vadim)
fix rtree for use in inner scan (Vadim)
fix gist for use in inner scan, cleanups (Vadim, Andrea)
avoid unnecessary local buffers allocation (Vadim, Massimo)
fix local buffers leak in transaction aborts (Vadim)
fix file manager memmory leaks, cleanups (Vadim, Massimo)
fix storage manager memmory leaks (Vadim)
fix btree duplicates handling (Vadim)
fix deleted tuples re-incarnation caused by vacuum (Vadim)
fix SELECT varchar()/char() INTO TABLE made zero-length fields(Bruce)
many psql, pg_dump, and libpq memory leaks fixed using Purify (Igor)

Enhancements
------------
attribute optimization statistics(Bruce)
much faster new btree bulk load code(Paul)
BTREE UNIQUE added to bulk load code(Vadim) 
new lock debug code(Massimo)
massive changes to libpg++(Leo)
new GEQO optimizer speeds table multi-table optimization(Martin)
new WARN message for non-unique insert into unique key(Marc)
update x=-3, no spaces, now valid(Bruce)
remove case-sensitive identifier handling(Bruce,Thomas,Dan)
debug backend now pretty-prints tree(Darren)
new Oracle character functions(Edmund)
new plaintext password functions(Dan)
no such class or insufficient privilege changed to distinct messages(Dan)
new ANSI timestamp function(Dan)
new ANSI Time and Date types (Thomas)
move large chunks of data in backend(Martin)
multi-column btree indexes(Vadim)
new SET var TO value command(Martin)
update transaction status on reads(Dan)
new locale settings for character types(Oleg)
new SEQUENCE serial number generator(Vadim)
GROUP BY function now possible(Vadim)
re-organize regression test(Thomas,Marc)
new optimizer operation weights(Vadim)
new psql \z grant/permit option(Marc)
new MONEY data type(D'Arcy,Thomas)
tcp socket communication speed improved(Vadim)
new VACUUM option for attribute statistics, and for certain columns (Vadim)
many geometric type improvements(Thomas,Keith)
additional regression tests(Thomas)
new datestyle variable(Thomas,Vadim,Martin)
more comparison operators for sorting types(Thomas)
new conversion functions(Thomas)
new more compact btree format(Vadim)
allow pg_dumpall to preserve database ownership(Bruce)
new SET GEQO=# and R_PLANS variable(Vadim)
old (!GEQO) optimizer can use right-sided plans (Vadim)
typechecking improvement in SQL parser(Bruce)
new SET, SHOW, RESET commands(Thomas,Vadim)
new \connect database USER option
new destroydb -i option (Igor)
new \dt and \di psql commands (Darren)
SELECT "\n" now escapes newline (A. Duursma)
new geometry conversion functions from old format (Thomas)

Source tree changes
-------------------
new configuration script(Marc)
readline configuration option added(Marc)
OS-specific configuration options removed(Marc)
new OS-specific template files(Marc)
no more need to edit Makefile.global(Marc)
re-arrange include files(Marc)
nextstep patches (Gregor Hoffleit)
removed WIN32-specific code(Bruce)
removed postmaster -e option, now only postgres -e option (Bruce)
merge duplicate library code in front/backends(Martin)
now works with eBones, international Kerberos(Jun)
more shared library support
c++ include file cleanup(Bruce)
warn about buggy flex(Bruce)
DG-UX, Ultrix, Irix, AIX portability fixes