postgresql/doc/TODO

TODO list for PostgreSQL
========================
Last updated:		Sun Jun  6 22:08:59 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>
	* Hiroshi is Hiroshi Inoue<Inoue@tpf.co.jp>
	* 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)
* 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
------------
* Add referential integrity
* Add OUTER joins, left and right(Thomas)
* Allow long tuples by chaining or auto-storing outside db (chaining,large objs)
* Fix memory leak for expressions?, aggregates?

Exotic features:
* Add sql3 recursive unions
* Add the concept of dataspaces
* Add replication of distributed databases
* Allow queries across multiple databases

Admin:
* Better interface for adding to pg_group
* More access control over who can create tables and access the database
* Add syslog functionality
* Allow elog() to return error codes, not just messages
* Allow international error message support and add error codes
* Generate postmaster pid file and remove flock/fcntl lock code
* Add ability to specifiy location of lock/socket files

Types:
* Add BIT, BIT VARYING
* Nchar (as distinguished from ordinary varchar),
* Domain capability
* Add STDDEV/VARIANCE() function for standard deviation computation/variance
* 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
* Allow pg_descriptions when creating types, tables, columns, and functions
* Add IPv6 capability to INET/CIDR types
* Make a separate SERIAL type?
* Store binary-compatible type information in the system
* Allow user to define char1 column
* Add support for & operator

Views:
* Allow DISTINCT on views
* Allow views of aggregate columns
* Allow views with subselects

* Allow subqueries in target list
* Put sort files, large objects in their on directory
* Do autocommit so always in a transaction block
* Show location of syntax error in query
* Redesign the function call interface to handle NULLs better(Jan)
* Document/trigger/rule so changes to pg_shadow create pg_pwd
* Missing optimizer selectivities for date, etc.

Indexes:
* Allow CREATE INDEX zman_index ON test (date_trunc( 'day', zman ) datetime_ops)
	fails index can't store constant parameters
* Allow creation of functional indexes to use default types
* Permissions on indexes - prevent them?
* Allow SQL function indexes
* Add FILLFACTOR to index creation

Commands:
* ALTER TABLE ADD COLUMN to inherited table put column in wrong place
* Add ALTER TABLE DROP/ALTER COLUMN feature
* Allow CLUSTER on all tables at once, and improve CLUSTER
* Generate error on CREATE OPERATOR of ~~, ~ and and ~*
* Add SIMILAR TO to allow character classes, 'pg_[a-c]%'
* Auto-destroy sequence on DROP of table with SERIAL
* Allow LOCK TABLE tab1, tab2, tab3 so all tables locked in unison
* Allow INSERT/UPDATE of system-generated oid value for a row
* Allow ESCAPE '\' at the end of LIKE for ANSI compliance
* Rewrite the LIKE handling by rewriting the user string with the 
	supplied ESCAPE
* Move LIKE index optimization handling to the optimizer
  
Clients:
* Make NULL's come out at the beginning or end depending on the 
	ORDER BY direction
* Allow flag to control COPY input/output of NULLs
* Update reltuples from COPY command
* Allow psql \copy to allow delimiters
* Add a function to return the last inserted oid, for use in psql scripts
* Allow psql to print nulls as distinct from ""(?)

* Increase identifier length(NAMEDATALEN) if small performance hit
* Allow row re-use without vacuum, maybe?(Vadim)
* Add UNIQUE capability to non-btree indexes
* Certain indexes will not shrink, i.e. oid indexes with many inserts
* 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 cursors to be DECLAREd/OPENed/CLOSEed outside transactions
* Allow PQrequestCancel() to terminate when in waiting-for-lock state
* Transaction log, so re-do log can be on a separate disk
* Populate backend status area and write program to dump status data
* Make oid use unsigned int more reliably, pg_atoi()

* Add PL/Perl(Mark Hollomon)


PERFORMANCE
-----------
* Allow transaction commits with rollback with no-fsync performance
* Prevent fsync in SELECT-only queries

* Use indexes in ORDER BY for restrictive data sets, min(), max()
* Pull requested data directly from indexes, bypassing heap data
* 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

* Allow LIMIT ability on single-table queries that have no ORDER BY to use
	a matching index
* Improve LIMIT processing by using index to limit rows processed

* 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
* 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(?)
* Process const = const parts of OR clause in separate pass
* Make oid use oidin/oidout not int4in/int4out in pg_type.h
* Create more system table indexes for faster cache lookups
* Improve Subplan list handling
* Allow Subplans to use efficient joins(hash, merge) with upper variable


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