TODO list for PostgreSQL

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

Last updated:Wed Nov 6 00:12:55 EST 2002

Last updated:Wed Nov 6 00:55:00 EST 2002

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

The most recent version of this document can be viewed at

the PostgreSQL web site, http://www.PostgreSQL.org.

A dash (-) marks changes that will appear in the upcoming 7.3 release.

A dash (-) marks changes that will appear in the upcoming 7.4 release.

Bracketed items "[]" have more detailed.

number, not just messages (Peter E)

* Add error codes (Peter E)

* Make error messages more consistent [error]

* -Change DEBUG startup tag to LOG (Bruce)

* Show location of syntax error in query [yacc]

* -Add pg_backend_pid() function to backend

* -Allow logging of query durations

Permissions

===========

* -Improve control over user privileges, including table creation

* -Allow user/group names to be specified directly in pg_hba.conf (Bruce)

* -Add ~/.pgpass to store passwords with user/host/password combinations

* -Allow permissions for functions (Peter E)

* -Allow object creation to be disabled for specific users

Administration

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

* Incremental backups

* -Make it easier to create a database owned by someone who can't createdb,

perhaps CREATE DATABASE dbname WITH OWNER = "user" (Gavin)

* -Make equals sign optional in CREATE DATABASE WITH param = 'val'

* Remove unreferenced table files and temp tables during database vacuum

or postmaster startup (Bruce)

* Remove behavior of postmaster -o after making postmaster/postgres

flags unique

* -Prevent SIGHUP and 'pg_ctl reload' from changing command line

specified parameters to postgresql.conf defaults (Peter E)

* Allow easy display of usernames in a group

* Allow configuration files to be specified in a different directory

* -Reserve last few process slots for super-user if max_connections reached

* -Add GUC parameter to print queries that generate errors

* Add start time to pg_stat_activity

* Allow limits on per-db/user connections

* Have standalone backend read postgresql.conf

Data Types

==========

* -Add domain capability (Rod Taylor)

* Add IPv6 capability to INET/CIDR types

* Remove Money type, add money formatting for decimal type

* -SELECT cash_out(2) crashes because of opaque

* -Declare typein/out functions in pg_proc with a special "C string" data type

* -Functions returning sets do not totally work

* Change factorial to return a numeric

* Change NUMERIC data type to use base 10,000 internally

* Change NUMERIC to enforce the maximum precision, and increase it

* Add function to return compressed length of TOAST data values (Tom)

* -Add GUC parameter for DATESTYLE

* Allow INET subnet tests using non-constants

* -Allow bytea to handle LIKE with non-TEXT patterns

* -to_char(0,'FM999.99') returns a period, to_char(1,'FM999.99') doesn't (Karel)

* -Add floor(float8) and other missing functions

* Add now("transaction|statement|clock") functionality

* CONVERSION

o -Store binary-compatible type information in the system

o Allow better handling of numeric constants, type conversion

[typeconv]

* ARRAYS

o Allow nulls in arrays

o Allow arrays to be ORDER'ed

o -Ensure we have array-eq operators for every built-in array type

o Support construction of array result values in expressions

* BINARY DATA

* Have views on temporary tables exist in the temporary namespace

* Move psql backslash information into views

* Allow RULE recompilation

* -Remove brackets as multi-statement rule grouping, must use parens (Bruce)

* -Prevent aggregates from being used in rule WHERE clauses

Indexes

* UNIQUE INDEX on base column not honored on inserts from inherited table

INSERT INTO inherit_table (unique_index_col) VALUES (dup) should fail

[inheritance]

* -Allow UPDATE/DELETE on inherited table

* Add UNIQUE capability to non-btree indexes

* Add btree index support for reltime, tinterval, regproc

* Add rtree index support for line, lseg, path, point

* Use index to restrict rows returned by multi-key index when used with

non-consecutive keys or OR clauses, so fewer heap accesses

* Be smarter about insertion of already-ordered data into btree index

* -Add deleted bit to index tuples to reduce heap access

* Prevent index uniqueness checks when UPDATE does not modifying column

* Use bitmaps to fetch heap pages in sequential order [performance]

* Use bitmaps to combine existing indexes [performance]

* Add FILLFACTOR to btree index creation

* Add concurrency to GIST

* Improve concurrency of hash indexes (Neil)

* -Test hash index performance and discourage usage

Commands

========

* -Add SIMILAR TO to allow character classes, 'pg_[a-c]%'

* Add BETWEEN ASYMMETRIC/SYMMETRIC (Christopher)

* -Remove LIMIT #,# and force use LIMIT and OFFSET clauses in 7.3 (Bruce)

* Allow LIMIT/OFFSET to use expressions

* -Disallow TRUNCATE on tables that are involved in referential constraints

* -Add OR REPLACE clauses to non-FUNCTION object creation

* CREATE TABLE AS can not determine column lengths from expressions [atttypmod]

* Allow UPDATE to handle complex aggregates [update]

* -Prevent create/drop scripts from allowing extra args (Bruce)

* Allow command blocks to ignore certain types of errors

* Allow backslash handling in quoted strings to be disabled for portability

* Return proper effected tuple count from complex commands [return]

* ALTER

o ALTER TABLE ADD COLUMN does not honor DEFAULT and non-CHECK CONSTRAINT

o -Add ALTER TABLE DROP COLUMN feature

o -Add ALTER TABLE DROP non-CHECK CONSTRAINT

o -ALTER TABLE ADD PRIMARY KEY (Tom)

o -ALTER TABLE ADD UNIQUE (Tom)

o -ALTER TABLE ALTER COLUMN SET/DROP NOT NULL (Christopher)

o ALTER TABLE ADD COLUMN column DEFAULT should fill existing

rows with DEFAULT value

o ALTER TABLE ADD COLUMN column SERIAL doesn't create sequence because

of the item above

o -Have ALTER TABLE OWNER change all dependant objects like indexes

o Add ALTER TABLE tab SET WITHOUT OIDS

* CLUSTER

o -Cluster all tables at once using pg_index.indisclustered set during

previous CLUSTER

o -Prevent loss of indexes, permissions, inheritance

o Automatically maintain clustering on a table

o Allow CLUSTER to cluster all tables, remove clusterdb

* COPY

o -Allow specification of column names

o Allow psql \copy to specify column names

o Allow dump/load of CSV format

o -Change syntax to WITH DELIMITER, (keep old syntax around?)

o Allow COPY to report error lines and continue; optionally

allow error codes to be specified; requires savepoints or can

not be run in a multi-statement transaction

o -Generate failure on short COPY lines rather than pad NULLs

o Allow copy to understand \x as hex

* CURSOR

* INSERT

o Allow INSERT/UPDATE of system-generated oid value for a row

o Allow INSERT INTO tab (col1, ..) VALUES (val1, ..), (val2, ..)

o -Allow INSERT INTO my_table VALUES (a, b, c, DEFAULT, x, y, z, ...)

o -Disallow missing columns in INSERT ... (col) VALUES, per ANSI

o Allow INSERT/UPDATE ... RETURNING new.col or old.col; handle

RULE cases (Philip)

* SHOW/SET

o -Add command to display locks

o -Add SET or BEGIN timeout parameter to cancel query

o Add SET REAL_FORMAT and SET DOUBLE_PRECISION_FORMAT using printf args

o -Remove SET KSQO option now that OR processing is improved (Bruce)

o Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM

ANALYZE, and CLUSTER

o -Add SHOW command to see locale

o -Allow SHOW to output as a query result, like EXPLAIN

o -Abort all SET changes made in an aborted transaction

o Add SET SCHEMA

o Allow EXPLAIN EXECUTE to see prepared plans

o Allow SHOW of non-modifiable variables, like pg_controldata

o Add GUC parameter to control the maximum number of rewrite cycles

* SERVER-SIDE LANGUAGES

o Allow PL/PgSQL's RAISE function to take expressions

o -Fix PL/PgSQL to handle quoted mixed-case identifiers

o Change PL/PgSQL to use palloc() instead of malloc()

o Add untrusted version of plpython

o Allow Java server-side programming, http://pljava.sourceforge.net

Clients

=======

* -Have pg_dump use LEFT OUTER JOIN in multi-table SELECTs

or multiple SELECTS to avoid bad system catalog entries

* -Have pg_dump -C dump database location and encoding information

* -Allow psql \d to show foreign keys

* -Allow psql \d to show temporary table structure (Tom)

* Allow psql to show transaction status if backend protocol changes made

* Add XML interface: psql, pg_dump, COPY, separate server (?)

* -Have pg_dump use ADD PRIMARY KEY after COPY, for performance (Neil)

* Add schema, cast, and conversion backslash commands to psql

* Allow pg_dump to dump a specific schema

* Allow psql to do table completion for SELECT * FROM schema_part and

table completion for SELECT * FROM schema_name.

* JDBC

o Comprehensive test suite. This may be available already.

o -Updateable resultSet

o JDBC-standard BLOB support

o Error Codes (pending backend implementation)

o Support both 'make' and 'ant'

o Fix LargeObject API to handle OIDs as unsigned ints

o -Implement cancel() method on Statement

o Use cursors implicitly to avoid large results (see setCursorName())

o -Add support for CallableStatements

o Add LISTEN/NOTIFY support to the JDBC driver (Barry)

o -Compile under jdk 1.4

* ECPG

o Implement set descriptor, using descriptor

* Add MATCH PARTIAL referential integrity [foreign]

* Add deferred trigger queue file (Jan)

* -Allow oid to act as a foreign key

* Implement dirty reads and use them in RI triggers

* Enforce referential integrity for system tables

* -Allow user to control trigger firing order (Tom)

* -Add ALTER TRIGGER ... RENAME

* Change foreign key constraint for array -> element to mean element

in array

* -Fix foreign key constraints to not error on intermediate db states (Stephan)

* Allow DEFERRABLE UNIQUE constraints

* Allow triggers to be disabled [trigger]

* Support statement-level triggers and triggers on columns (Neil)

Dependency Checking

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

* -Add pg_depend table for dependency recording; use sysrelid, oid,

depend_sysrelid, depend_oid, name

* -Auto-destroy sequence on DROP of table with SERIAL; perhaps a separate

SERIAL type

* -Prevent column dropping if column is used by foreign key

* -Propagate column or table renaming to foreign key constraints

* -Automatically drop constraints/functions when object is dropped

* -Make foreign key constraints clearer in dump file

* -Make other constraints clearer in dump file

* -Make foreign keys easier to identify

* Flush cached query plans when their underlying catalog data changes

* Use dependency information to dump data in proper order

Transactions

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

* -Allow autocommit so always in a transaction block

* Overhaul bufmgr/lockmgr/transaction manager

* Allow savepoints / nested transactions [transactions]

* Add sql3 recursive unions

* Add the concept of dataspaces/tablespaces [tablespaces]

* -Add SQL92 schemas (Tom)

* Allow queries across multiple databases [crossdb]

* Add pre-parsing phase that converts non-ANSI features to supported features

* Allow plug-in modules to emulate features from other databases

Cache

=====

* -Cache most recent query plan(s) (Neil) [prepare]

* Shared catalog cache, reduce lseek()'s by caching table size in shared area

* Add free-behind capability for large sequential scans (Bruce)

* Allow binding query args over FE/BE protocol

* Do listen() in postmaster and accept() in pre-forked backend

* Have pre-forked backend pre-connect to last requested database or pass

file descriptor to backend pre-forked for matching database

* -Cache system catalog information in per-database files (Tom)

Write-Ahead Log

partial page writes [wal]

* Turn off after-change writes if fsync is disabled (?)

* Add WAL index reliability improvement to non-btree indexes

* -Reorder postgresql.conf WAL items in order of importance (Bruce)

* -Remove wal_files postgresql.conf option because WAL files are now recycled

* Find proper defaults for postgresql.conf WAL entries

* Add checkpoint_min_warning postgresql.conf option to warn about checkpoints

that are too frequent

* Improve Subplan list handling

* Allow Subplans to use efficient joins(hash, merge) with upper variable

* -Improve dynamic memory allocation by introducing tuple-context memory

allocation (Tom)

* Add hash for evaluating GROUP BY aggregates

* -Nested FULL OUTER JOINs don't work (Tom)

* Allow merge and hash joins on expressions not just simple variables (Tom)

* -Add new pg_proc cachable settings to specify whether function can be

evaluated only once or once per query

* -Change FIXED_CHAR_SEL to 0.20 from 0.04 to give better selectivity (Bruce)

* Make IN/NOT IN have similar performance to EXISTS/NOT EXISTS [exists]

* Missing optimizer selectivities for date, r-tree, etc. [optimizer]

* Allow ORDER BY ... LIMIT to select top values without sort or index

when it is available

* Use mmap() rather than SYSV shared memory or to write WAL files (?) [mmap]

* Improve caching of attribute offsets when NULLs exist in the row

* -Add Intimate Shared Memory(ISM) for Solaris

* -Use faster flex flags for performance improvement (Peter E)

* -Add BSD-licensed qsort() for Solaris

Source Code

===========

* Add use of 'const' for variables in source tree

* -Fix problems with libpq non-blocking/async code

* -Make sure all block numbers are unsigned to increase maximum table size

* -Merge LockMethodCtl and LockMethodTable into one shared structure (Bruce)

* -HOLDER/HOLDERTAB rename to PROCLOCK/PROCLOCKTAG (Bruce)

* -Remove LockMethodTable.prio field, not used (Bruce)

* Rename some /contrib modules from pg* to pg_*

* Move some things from /contrib into main tree

* Remove warnings created by -Wcast-align

* Move platform-specific ps status display info from ps_status.c to ports

* -Make one version of simple_prompt() in code (Bruce, Tom)

* -Compile in syslog functionaility by default (Tatsuo)

* Modify regression tests to prevent failures do to minor numeric rounding

* Add OpenBSD's getpeereid() call for local socket authentication (Bruce)

* Improve access-permissions check on data directory in Cygwin (Tom)

* -Report failure to find readline or zlib at end of configure run

* Add --port flag to regression tests

* -Increase identifier length (NAMEDATALEN) if small performance hit,

* -Increase maximum number of function parameters if little wasted space

* Add documentation for perl, including mention of DBI/DBD perl location

* Add optional CRC checksum to heap and index pages

* Change representation of whole-tuple parameters to functions

* Remove or relicense modules that are not under the BSD license, if possible

* Remove memory/file descriptor freeing befor elog(ERROR) (Bruce)

* Create native Win32 port [win32]

* -Fix glibc's mktime() to handle pre-1970's dates

* -Move /contrib/retep to gborg.postgresql.org

* Acquire lock on a relation before building a relcache entry for it

* Move dbmirror and rserv from /contrib to gborg.postgresql.org