1 TODO list for PostgreSQL
2 ========================
3 Last updated: Fri Aug 30 21:36:25 EDT 2002
5 Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
7 The most recent version of this document can be viewed at
8 the PostgreSQL web site, http://www.PostgreSQL.org.
10 A dash (-) marks changes that will appear in the upcoming 7.3 release.
12 Bracketed items "[]" have more detailed.
18 * Add replication of distributed databases [replication]
21 o master/slave replication
22 o multi-master replication
23 o partition data across servers
24 o sample implementation in contrib/rserv
25 o queries across databases or servers (two-phase commit)
26 o allow replication over unreliable or non-persistent links
27 o http://gborg.postgresql.org/project/pgreplication/projdisplay.php
28 * Point-in-time data recovery using backup and write-ahead log
34 * Allow elog() to return error codes, module name, file name, line
35 number, not just messages (Peter E)
36 * Add error codes (Peter E)
37 * Make error messages more consistent [error]
38 * -Change DEBUG startup tag to LOG (Bruce)
39 * Show location of syntax error in query [yacc]
40 * -Add getpid() function to backend
41 * Allow logging of query durations
47 * -Improve control over user privileges, including table creation
48 * -Allow user/group names to be specified directly in pg_hba.conf (Bruce)
49 * -Add PGPASSWORDFILE environment variable or ~/.pgpass to store
50 user/host/password combinations
51 * Make single-user local access permissions the default by limiting
52 permissions on the socket file (Peter E)
53 * -Allow permissions for functions (Peter E)
54 * -Allow object creation to be disabled for specific users
61 * -Make it easier to create a database owned by someone who can't createdb,
62 perhaps CREATE DATABASE dbname WITH OWNER = "user" (Gavin)
63 * -Make equals sign optional in CREATE DATABASE WITH param = 'val'
64 * Remove unreferenced table files and temp tables during database vacuum
65 or postmaster startup (Bruce)
66 * Remove behavior of postmaster -o after making postmaster/postgres
68 * -Prevent SIGHUP and 'pg_ctl reload' from changing command line
69 specified parameters to postgresql.conf defaults (Peter E)
70 * Allow easy display of usernames in a group
71 * Allow configuration files to be specified in a different directory
72 * Reserve last few process slots for super-user if max_connections reached
73 * Add GUC parameter to print queries that generate errors
78 * -Add domain capability (Rod Taylor)
79 * Add IPv6 capability to INET/CIDR types
80 * Remove Money type, add money formatting for decimal type
81 * -SELECT cash_out(2) crashes because of opaque
82 * Declare typein/out functions in pg_proc with a special "C string" data type
83 * Functions returning sets do not totally work
84 * Change factorial to return a numeric
85 * Change NUMERIC data type to use base 10,000 internally
86 * Change NUMERIC to enforce the maximum precision, and increase it
87 * Add function to return compressed length of TOAST data values (Tom)
88 * -Add GUC parameter for DATESTYLE
89 * Allow INET subnet tests using non-constants
90 * Allow bytea to handle LIKE with non-TEXT patterns
94 o Store binary-compatible type information in the system
95 o Allow better handling of numeric constants, type conversion
97 o SELECT col FROM tab WHERE numeric_col = 10.1 fails, requires quotes
100 o Allow nulls in arrays
101 o Allow arrays to be ORDER'ed
102 o Ensure we have array-eq operators for every built-in array type
103 o Support construction of array result values in expressions
106 o Improve vacuum of large objects, like /contrib/vacuumlo
107 o Add security checking for large objects
108 o Make file in/out interface for TOAST columns, similar to large object
109 interface (force out-of-line storage and no compression)
110 o Auto-delete large objects when referencing row is deleted
113 Multi-Language Support
114 ======================
116 * Add NCHAR (as distinguished from ordinary varchar),
117 * Allow LOCALE on a per-column basis, default to ASCII
118 * Support multiple simultaneous character sets, per SQL92
119 * Allow setting database character set without multibyte enabled
120 * Improve Unicode combined character handling
121 * Optimize locale to have minimal performance impact when not used (Peter E)
122 * Add octet_length_server() and octet_length_client() (Thomas, Tatsuo)
123 * Make octet_length_client the same as octet_length() (?)
124 * Prevent mismatch of frontend/backend encodings from converting bytea
125 data from being interpreted as encoded strings
130 * Automatically create rules on views so they are updateable, per SQL92 [view]
131 * Add the functionality for WITH CHECK OPTION clause of CREATE VIEW
132 * Allow NOTIFY in rules involving conditionals
133 * Have views on temporary tables exist in the temporary namespace
134 * Move psql backslash information into views
135 * Allow RULE recompilation
136 * -Remove brackets as multi-statement rule grouping, must use parens (Bruce)
137 * Prevent aggregates from being used in rule WHERE clauses
143 * Allow CREATE INDEX zman_index ON test (date_trunc( 'day', zman ) datetime_ops)
144 fails index can't store constant parameters
145 * Order duplicate index entries by tid for faster heap lookups
146 * Allow inherited tables to inherit index, UNIQUE constraint, and primary
147 key, foreign key [inheritance]
148 * UNIQUE INDEX on base column not honored on inserts from inherited table
149 INSERT INTO inherit_table (unique_index_col) VALUES (dup) should fail
151 * -Allow UPDATE/DELETE on inherited table
152 * Have UPDATE/DELETE clean out indexes
153 * Add UNIQUE capability to non-btree indexes
154 * Add btree index support for reltime, tinterval, regproc
155 * Add rtree index support for line, lseg, path, point
156 * Certain indexes will not shrink, e.g. indexes on ever-increasing
157 columns and indexes with many duplicate keys
158 * Use indexes for min() and max() or convert to SELECT col FROM tab ORDER
159 BY col DESC LIMIT 1 if appropriate index exists and WHERE clause acceptible
160 * Allow LIKE indexing optimization for non-ASCII locales
161 * Use index to restrict rows returned by multi-key index when used with
162 non-consecutive keys or OR clauses, so fewer heap accesses
163 * Be smarter about insertion of already-ordered data into btree index
164 * -Add deleted bit to index tuples to reduce heap access
165 * Prevent index uniqueness checks when UPDATE does not modifying column
166 * Use bitmaps to fetch heap pages in sequential order [performance]
167 * Use bitmaps to combine existing indexes [performance]
168 * Improve handling of index scans for NULL
169 * Allow SELECT * FROM tab WHERE int2col = 4 to use int2col index, int8,
170 float4, numeric/decimal too [optimizer]
171 * Add FILLFACTOR to btree index creation
172 * Improve concurrency in GIST
173 * Improve concurrency of hash indexes (Neil Conway)
174 * -Test hash index performance and discourage usage
180 * -Add SIMILAR TO to allow character classes, 'pg_[a-c]%'
181 * Add BETWEEN ASYMMETRIC/SYMMETRIC (Christopher)
182 * -Remove LIMIT #,# and force use LIMIT and OFFSET clauses in 7.3 (Bruce)
183 * Allow LIMIT/OFFSET to use expressions
184 * -Disallow TRUNCATE on tables that are involved in referential constraints
185 * Add OR REPLACE clauses to non-FUNCTION object creation
186 * CREATE TABLE AS can not determine column lengths from expressions [atttypmod]
187 * Allow UPDATE to handle complex aggregates [update]
188 * -Prevent create/drop scripts from allowing extra args (Bruce)
189 * Allow command blocks to ignore certain types of errors
190 * Allow backslash handling in quoted strings to be disabled for portability
191 * Return proper effected tuple count from complex commands [return]
192 * Allow DELETE to handle table aliases for self-joins [delete]
193 * Add CORRESPONDING BY to UNION/INTERSECT/EXCEPT
194 * Allow REINDEX to rebuild all indexes, remove /contrib/reindex
197 o ALTER TABLE ADD COLUMN does not honor DEFAULT and non-CHECK CONSTRAINT
198 o ALTER TABLE ADD COLUMN to inherited table put column in wrong place
200 o -Add ALTER TABLE DROP COLUMN feature
202 o -Add ALTER TABLE DROP non-CHECK CONSTRAINT
203 o -ALTER TABLE ADD PRIMARY KEY (Tom)
204 o -ALTER TABLE ADD UNIQUE (Tom)
205 o -ALTER TABLE ALTER COLUMN SET/DROP NOT NULL (Christopher Kings-Lynne)
206 o ALTER TABLE ADD COLUMN column SERIAL doesn't create sequence
207 o ALTER TABLE ADD COLUMN column DEFAULT should fill existing
208 rows with DEFAULT value
209 o -Have ALTER TABLE OWNER change all dependant objects like indexes
210 o Add ALTER TABLE tab SET WITHOUT OIDS
213 o -Cluster all tables at once using pg_index.indisclustered set during
215 o -Prevent loss of indexes, permissions, inheritance
216 o Automatically maintain clustering on a table
217 o Allow CLUSTER to cluster all tables, remove clusterdb
220 o -Allow specification of column names
221 o Allow dump/load of CSV format
222 o -Change syntax to WITH DELIMITER, (keep old syntax around?)
223 o Allow COPY to report error lines and continue; optionally
224 allow error codes to be specified; requires savepoints or can
225 not be run in a multi-statement transaction
226 o -Generate failure on short COPY lines rather than pad NULLs
229 o Allow BINARY option to SELECT, just like DECLARE
230 o MOVE 0 should not move to end of cursor
231 o Allow UPDATE/DELETE WHERE CURRENT OF cursor using per-cursor tid
232 stored in the backend
233 o Prevent DROP of table being referenced by our own open cursor
234 o Allow cursors outside transactions [cursor]
237 o Allow INSERT/UPDATE of system-generated oid value for a row
238 o Allow INSERT INTO tab (col1, ..) VALUES (val1, ..), (val2, ..)
239 o -Allow INSERT INTO my_table VALUES (a, b, c, DEFAULT, x, y, z, ...)
240 o -Disallow missing columns in INSERT ... VALUES, per ANSI
241 o Allow INSERT/UPDATE ... RETURNING new.col or old.col; handle
245 o -Add command to display locks
246 o -Add SET or BEGIN timeout parameter to cancel query
247 o Add SET REAL_FORMAT and SET DOUBLE_PRECISION_FORMAT using printf args
248 o -Remove SET KSQO option now that OR processing is improved (Tom)
249 o Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM
251 o Add SHOW command to see locale
252 o -Allow SHOW to output as a query result, like EXPLAIN
253 o -Abort all SET changes made in an aborted transaction
256 * SERVER-SIDE LANGUAGES
257 o Allow PL/PgSQL's RAISE function to take expressions
258 o -Fix PL/PgSQL to handle quoted mixed-case identifiers
259 o Change PL/PgSQL to use palloc() instead of malloc()
260 o Add untrusted version of plpython
261 o Allow Java server-side programming, http://pljava.sourceforge.net
263 o Fix problems with complex temporary table creation/destruction
264 without using PL/PgSQL EXECUTE, needs cache prevention/invalidation
265 o Fix PL/pgSQL RENAME to work on variables other than OLD/NEW
266 o Improve PL/PgSQL exception handling
267 o Allow parameters to be specified by name and type during
269 o Allow function parameters to be passed by name,
270 get_employee_salary(emp_id => 12345, tax_year => 2001)
271 o Add PL/PgSQL packages
272 o Allow array declarations and other data types in PL/PgSQl DECLARE
273 o Add PL/PgSQL PROCEDURES that can return multiple values
279 * Have pg_dump use LEFT OUTER JOIN in multi-table SELECTs
280 or multiple SELECTS to avoid bad system catalog entries
281 * -Have pg_dump -C dump database location and encoding information
282 * -Allow psql \d to show foreign keys
283 * -Allow psql \d to show temporary table structure (Tom)
284 * Allow psql to show transaction status if backend protocol changes made
285 * Add XML interface: psql, pg_dump, COPY, separate server (?)
286 * Add config file check for $ODBCINI, $HOME/.odbc.ini, installpath/etc/odbc.ini
287 * -Have pg_dump use ADD PRIMARY KEY after COPY, for performance (Neil Conway)
290 o Comprehensive test suite. This may be available already.
291 o -Updateable resultSet
292 o JDBC-standard BLOB support
293 o Error Codes (pending backend implementation)
294 o Support both 'make' and 'ant'
295 o Fix LargeObject API to handle OIDs as unsigned ints
296 o -Implement cancel() method on Statement
297 o Use cursors implicitly to avoid large results (see setCursorName())
298 o -Add support for CallableStatements
299 o Add LISTEN/NOTIFY support to the JDBC driver (Barry)
300 o -Compile under jdk 1.4
303 o Implement set descriptor, using descriptor
304 o Make casts work in variable initializations
306 o Allow multi-threaded use of SQLCA
307 o Solve cardinality > 1 for input descriptors / variables
308 o Understand structure definitions outside a declare section
309 o sqlwarn[6] should be 'W' if the PRECISION or SCALE value specified
310 o Improve error handling
311 o Allow :var[:index] or :var[<integer>] as cvariable for an array var
312 o Add a semantic check level, e.g. check if a table really exists
313 o Fix nested C comments
315 o fix handling of DB attributes that are arrays
319 o Unicode(UCS-2) support
320 o Updatable cursors support
323 Referential Integrity
324 =====================
326 * Add MATCH PARTIAL referential integrity [foreign]
327 * Add deferred trigger queue file (Jan)
328 * -Allow oid to act as a foreign key
329 * Implement dirty reads and use them in RI triggers
330 * Make triggers refer to columns by number, not name
331 * Enforce referential integrity for system tables
332 * -Allow user to control trigger firing order (Tom)
333 * -Add ALTER TRIGGER ... RENAME
334 * Change foreign key constraint for array -> element to mean element
336 * Fix foreign key constraints to not error on intermediate db states (Stephan)
337 * Allow DEFERRABLE UNIQUE constraints
338 * Allow triggers to be disabled [trigger]
344 * -Add pg_depend table for dependency recording; use sysrelid, oid,
345 depend_sysrelid, depend_oid, name
346 * -Auto-destroy sequence on DROP of table with SERIAL; perhaps a separate
348 * Have SERIAL generate non-colliding sequence names when we have
350 * -Prevent column dropping if column is used by foreign key
351 * Propagate column or table renaming to foreign key constraints
352 * -Automatically drop constraints/functions when object is dropped
353 * -Make foreign key constraints clearer in dump file
354 * -Make other constraints clearer in dump file
355 * -Make foreign keys easier to identify
356 * Flush cached query plans when their underlying catalog data changes
357 * Use dependency information to dump data in proper order
363 * Allow autocommit so always in a transaction block
364 * Overhaul bufmgr/lockmgr/transaction manager
365 * Allow savepoints / nested transactions [transactions]
371 * Add sql3 recursive unions
372 * Add the concept of dataspaces/tablespaces [tablespaces]
373 * -Add SQL92 schemas (Tom)
374 * Allow queries across multiple databases [crossdb]
375 * Add pre-parsing phase that converts non-ANSI features to supported features
376 * Allow plug-in modules to emulate features from other databases
377 * SQL*Net listener that makes PostgreSQL appear as an Oracle database
388 * Delay fsync() when other backends are about to commit too [fsync]
389 o Determine optimal commit_delay value
390 * Determine optimal fdatasync/fsync, O_SYNC/O_DSYNC options
391 o Allow multiple blocks to be written to WAL with one write()
396 * Cache most recent query plan(s) (Neil) [prepare]
397 * Shared catalog cache, reduce lseek()'s by caching table size in shared area
398 * Add free-behind capability for large sequential scans (Bruce)
399 * Allow binding query args over FE/BE protocol
400 * Consider use of open/fcntl(O_DIRECT) to minimize OS caching
401 * Make blind writes go through the file descriptor cache
407 * Improve speed with indexes (perhaps recreate index instead) [vacuum]
408 * Reduce lock time by moving tuples with read lock, then write
409 lock and truncate table [vacuum]
410 * Provide automatic running of vacuum in the background (Tom)
411 * Allow free space map to be auto-sized or warn when it is too small
416 * Make locking of shared data structures more fine-grained
417 * Add code to detect an SMP machine and handle spinlocks accordingly
418 from distributted.net, http://www1.distributed.net/source,
419 in client/common/cpucheck.cpp
420 * Research use of sched_yield() for spinlock acquisition failure
426 * Experiment with multi-threaded backend [thread]
427 * Add connection pooling [pool]
428 * Allow persistent backends [persistent]
429 * Create a transaction processor to aid in persistent connections and
431 * Do listen() in postmaster and accept() in pre-forked backend
432 * Have pre-forked backend pre-connect to last requested database or pass
433 file descriptor to backend pre-forked for matching database
434 * -Cache system catalog information in per-database files (Tom)
440 * Have after-change WAL write()'s write only modified data to kernel
441 * Reduce number of after-change WAL writes; they exist only to gaurd against
442 partial page writes [wal]
443 * Turn off after-change writes if fsync is disabled (?)
444 * Add WAL index reliability improvement to non-btree indexes
445 * -Reorder postgresql.conf WAL items in order of importance (Bruce)
446 * Remove wal_files postgresql.conf option because WAL files are now recycled
447 * Find proper defaults for postgresql.conf WAL entries
448 * Add checkpoint_min_warning postgresql.conf option to warn about checkpoints
449 that are too frequent
450 * Allow xlog directory location to be specified during initdb, perhaps
457 * Improve Subplan list handling
458 * Allow Subplans to use efficient joins(hash, merge) with upper variable
459 * Improve dynamic memory allocation by introducing tuple-context memory
461 * Add hash for evaluating GROUP BY aggregates
462 * Nested FULL OUTER JOINs don't work (Tom)
463 * Allow merge and hash joins on expressions not just simple variables (Tom)
464 * -Add new pg_proc cachable settings to specify whether function can be
465 evaluated only once or once per query
466 * -Change FIXED_CHAR_SEL to 0.20 from 0.04 to give better selectivity (Bruce)
467 * Make IN/NOT IN have similar performance to EXISTS/NOT EXISTS [exists]
468 * Missing optimizer selectivities for date, r-tree, etc. [optimizer]
469 * Allow ORDER BY ... LIMIT to select top values without sort or index
470 using a sequential scan for highest/lowest values (Oleg)
471 * Inline simple SQL functions to avoid overhead (Tom)
472 * Precompile SQL functions to avoid overhead (Neil Conway)
473 * Add utility to compute accurate random_page_cost value
474 * Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
475 * Use CHECK constraints to improve optimizer decisions
481 * Do async I/O for faster random read-ahead of data
482 * Get faster regex() code from Henry Spencer <henry@zoo.utoronto.ca>
484 * Use mmap() rather than SYSV shared memory or to write WAL files (?) [mmap]
485 * Improve caching of attribute offsets when NULLs exist in the row
486 * -Add Intimate Shared Memory(ISM) for Solaris
487 * Add documentation to lock shared memory into RAM for each OS, if possible
488 * -Use faster flex flags for performance improvement (Peter E)
489 * -Add BSD-licensed qsort() for Solaris
495 * Add use of 'const' for variables in source tree
496 * -Fix problems with libpq non-blocking/async code
497 * -Make sure all block numbers are unsigned to increase maximum table size
498 * -Merge LockMethodCtl and LockMethodTable into one shared structure (Bruce)
499 * -HOLDER/HOLDERTAB rename to PROCLOCK/PROCLOCKTAG (Bruce)
500 * -Remove LockMethodTable.prio field, not used (Bruce)
501 * Rename some /contrib modules from pg* to pg_*
502 * Move some things from /contrib into main tree
503 * Remove warnings created by -Wcast-align
504 * Move platform-specific ps status display info from ps_status.c to ports
505 * -Make one version of simple_prompt() in code (Bruce, Tom)
506 * -Compile in syslog functionaility by default (Tatsuo)
507 * Modify regression tests to prevent failures do to minor numeric rounding
508 * Add OpenBSD's getpeereid() call for local socket authentication (Bruce)
509 * Improve access-permissions check on data directory in Cygwin (Tom)
510 * -Report failure to find readline or zlib at end of configure run
511 * Add --port flag to regression tests
512 * -Increase identifier length (NAMEDATALEN) if small performance hit,
513 * -Increase maximum number of function parameters if little wasted space
514 * Add documentation for perl, including mention of DBI/DBD perl location
515 * Add optional CRC checksum to heap and index pages
516 * Change representation of whole-tuple parameters to functions
517 * Evaluate AIX cs() spinlock macro for performance optimizations (Tatsuo)
518 * Clarify use of 'application' and 'command' tags in SGML docs
519 * Better document ability to build only certain interfaces (Marc)
520 * Remove or relicense modules that are not under the BSD license, if possible
521 * Remove memory/file descriptor freeing befor elog(ERROR) (Bruce)
522 * Create native Win32 port [win32]
523 * Fix glibc's mktime() to handle pre-1970's dates
526 ---------------------------------------------------------------------------
529 Developers who have claimed items are:
530 --------------------------------------
531 * Barry is Barry Lind <barry@xythos.com>
532 * Billy is Billy G. Allie <Bill.Allie@mug.org>
533 * Bruce is Bruce Momjian <pgman@candle.pha.pa.us>
534 * Christopher is Christopher Kings-Lynne <chriskl@familyhealth.com.au>
535 * D'Arcy is D'Arcy J.M. Cain <darcy@druid.net>
536 * Dave is Dave Cramer <dave@fastcrypt.com>
537 * Edmund is Edmund Mergl <E.Mergl@bawue.de>
538 * Hiroshi is Hiroshi Inoue <Inoue@tpf.co.jp>
539 * Karel is Karel Zak <zakkr@zf.jcu.cz>
540 * Jan is Jan Wieck <wieck@sapserv.debis.de>
541 * Liam is Liam Stewart <liams@redhat.com>
542 * Marc is Marc Fournier <scrappy@hub.org>
543 * Mark is Mark Hollomon <mhh@mindspring.com>
544 * Marko is Marko Kreen <marko@l-t.ee>
545 * Michael is Michael Meskes <meskes@postgresql.org>
546 * Neil is Neil Conway <nconway@klamath.dyndns.org>
547 * Oleg is Oleg Bartunov <oleg@sai.msu.su>
548 * Peter M is Peter T Mount <peter@retep.org.uk>
549 * Peter E is Peter Eisentraut <peter_e@gmx.net>
550 * Philip is Philip Warner <pjw@rhyme.com.au>
551 * Rod is Rod Taylor <rbt@zort.ca>
552 * Ross is Ross J. Reedstrom <reedstrm@wallace.ece.rice.edu>
553 * Ryan is Ryan Bradetich <rbrad@hpb50023.boi.hp.com>
554 * Stephan is Stephan Szabo <sszabo@megazone23.bigpanda.com>
555 * Tatsuo is Tatsuo Ishii <t-ishii@sra.co.jp>
556 * Thomas is Thomas Lockhart <lockhart@fourpalms.org>
557 * Tom is Tom Lane <tgl@sss.pgh.pa.us>
558 * TomH is Tom I Helbekkmo <tih@Hamartun.Priv.no>
559 * Vadim is Vadim B. Mikheev <vadim4o@email.com>