postgresql/doc/TODO

TODO list for PostgreSQL
========================
Last updated:		Fri Jun  4 23:16:01 EDT 1999

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.

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>
	* David is David Hartwig <daveh@insightdist.com>
	* Edmund is Edmund Mergl <E.Mergl@bawue.de>
	* Goran is Goran Thyni <goran@kyla.kiruna.se>
	* Jan is Jan Wieck <wieck@sapserv.debis.de>
 	* Marc is Marc Fournier <scrappy@hub.org>
	* Massimo Dal Zotto <dz@cs.unitn.it>
	* Michael is Michael Meskes <meskes@debian.org>
	* Oleg is Oleg Bartunov <oleg@sai.msu.su>
	* Peter is Peter T Mount <peter@retep.org.uk>
	* Stefan Simkovics <ssimkovi@rainbow.studorg.tuwien.ac.at>
	* Tatsuo is Tatsuo Ishii <t-ishii@sra.co.jp>
	* Tom is Tom Lane <tgl@sss.pgh.pa.us>
	* Thomas is Thomas Lockhart <lockhart@alumni.caltech.edu>
	* TomH is Tom I Helbekkmo <tih@Hamartun.Priv.NO>

	* Vadim is "Vadim B. Mikheev" <vadim@krs.ru>

RELIABILITY
-----------
* Overhaul mdmgr/smgr to fix double unlinking and double opens, cleanup
* Overhaul bufmgr/lockmgr/transaction manager
* Remove EXTEND?
* Tables that start with xinv confused to be large objects
* Two and three dimensional arrays display improperly, missing {}
* 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
* 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
* views containing aggregates sometimes fail(Jan)
* ALTER TABLE ADD COLUMN does not honor DEFAULT, add CONSTRAINT
* array index references without table name cause problems
* views with spaces in view name fail when referenced
* plpgsql does not handle quoted mixed-case identifiers
* do not allow bpchar column creation without length
* INSERT INTO ... SELECT with AS columns matching result columns problem


ENHANCEMENTS
------------
* 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 sql3 recursive unions
	* add the concept of dataspaces
	* add BIT, BIT VARYING
 	* NCHAR (as distinguished from ordinary varchar),
	* DOMAIN capability
* Allow compression of large fields or a compressed field type
* Large objects
	* Fix large object mapping scheme, own typeid or reltype(Peter)
	* Allow large text type to use large objects(Peter)
	* not to stuff everything as files in a single directory
* Better interface for adding to pg_group
* allow row re-use without vacuum, maybe?(Vadim)
* Populate backend status area and write program to dump status data
* Add ALTER TABLE DROP/ALTER COLUMN feature
* Add syslog functionality
* Add STDDEV/VARIANCE() function for standard deviation computation/variance
* add UNIQUE capability to non-btree indexes
* 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
* Restore unused oid's on backend exit if no one else has gotten oids
* have UPDATE/DELETE clean out indexes
* allow WHERE restriction on ctid
* allow pg_descriptions when creating types, tables, columns, and functions
* Allow psql to print nulls as distinct from ""(?)
* Allow cursors to be DECLAREd/OPENed/CLOSEed outside transactions
* Allow DISTINCT on views
* Allow views of aggregate columns
* Allow flag to control COPY input/output of NULLs
* Allow CLUSTER on all tables at once, and improve CLUSTER
* Allow elog() to return error codes, not just messages
* allow international error message support and add error codes
* Allow subqueries in target list
* Allow queries across multiple databases
* Add replication of distributed databases
* Generate error on CREATE OPERATOR of ~~, ~ and and ~*
* allow psql \copy to allow delimiters
* 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
* do autocommit so always in a transaction block
* add SIMILAR TO to allow character classes, 'pg_[a-c]%'
* improve reporting of syntax errors by showing location of error in query
* allow chaining of pages to allow >8k tuples, auto-large object use
* redesign the function call interface to handle NULLs better(Jan)
* permissions on indexes - prevent them?
* document/trigger/rule so changes to pg_shadow create pg_pwd
* generate postmaster pid file and remove flock/fcntl lock code
* add ability to specifiy location of lock/socket files
* auto-destroy sequence on DROP of table with SERIAL
* make a separate serial type?
* allow user to define char1 column
* allow LOCK TABLE tab1, tab2, tab3 so all tables locked in unison
* allow INSERT/UPDATE of system-generated oid value for a row
* missing optimizer selectivities for date, etc.
* Add support for & operator
* store binary-compatible type information in the system
* Allow ESCAPE '\' at the end of LIKE for ANSI compliance
* rewrite the LIKE handling by rewriting the user string with the 
	supplied ESCAPE
* Fix memory leak for expressions?, aggregates?
* Allow Subplans to use efficient joins(hash, merge) with upper variable
* Update reltuples from COPY command
* Allow CREATE INDEX zman_index ON test (date_trunc( 'day', zman ) datetime_ops)
	fails index can't store constant parameters
* allow SQL function indexes
* ALTER TABLE ADD COLUMN to inherited table put column in wrong place
* Add IPv6 capability to INET/CIDR types
* Allow PQrequestCancel() to terminate when in waiting-for-lock state
* Increase identifier length(NAMEDATALEN) if small performance hit
* Fix for long table/column name auto-sequence serial name


PERFORMANCE
-----------
* Use indexes in ORDER BY for restrictive data sets, min(), max()
* Allow LIMIT ability on single-table queries that have no ORDER BY to use
	a matching index
* Pull requested data directly from indexes, bypassing heap data
* 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)
* Allow char() not to use variable-sized header to reduce disk size
* Do async I/O to do better read-ahead of data
* Fix memory exhaustion when using many OR's
* 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
* process const = const parts of OR clause in separate pass
* make oid use oidin/oidout not int4in/int4out in pg_type.h
* make oid use unsigned int more reliably, pg_atoi()
* create more system table indexes for faster cache lookups
* Move LIKE index optimization handling to the optimizer
* Improve LIMIT processing by using index to limit rows processed
* Improve Subplan list handling


DOCUMENTATION
-------------
* Add use of 'const' for varibles in source tree