TODO list for PostgreSQL ======================== Last updated: Fri Dec 15 17:03:28 EST 2000 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 7.1 release. Names in brackets "[]" indicate more detailed information is available in the directory pgsql/doc/TODO.detail/ under that name. RELIABILITY ----------- PARSER * SELECT pg_class FROM pg_class generates strange error * Alter TABLE ADD COLUMN does not honor DEFAULT, add CONSTRAINT * -Creating index of TIMESTAMP & RELTIME fails, or rename to DATETIME(Thomas) * -SELECT foo UNION SELECT foo is incorrectly simplified to SELECT foo * Unique index on base column not honored on inserts from inherited table INSERT INTO inherit_table (unique_index_col) VALUES (dup) should fail [inherit] * -Be smarter about promoting types when UNION merges different data types * -redesign INSERT ... SELECT to have two levels of target list * have INTERSECT/EXCEPT prevent duplicates unless ALL is specified * SELECT col::DECIMAL(12,10); fails VIEWS * -Views containing aggregates sometimes fail(Jan) * Creating view and inheriting the view causes view* to show duplicates(inherit) * -Disallow LOCK on view(Mark Hollomon) MISC * Plpgsql does not handle quoted mixed-case identifiers * Buffer reference counting bugfixes * Fix libpq bug that causes it to drop backend error message sent just before connection closure (ie, any FATAL error message) * -SELECT ... UNION ... ORDER BY fails when sort expr not in result list * -SELECT ... UNION ... GROUP BY fails if column types disagree, no type promotion occurs * Modification of pg_class can happen while table in use by another backend. Might lead to MVCC inside of syscache * Permission to DELETE table allows UPDATE also ENHANCEMENTS ------------ URGENT * -Add OUTER joins, left and right[outer](Tom, Thomas) * -Allow long tuples by chaining or auto-storing outside db (TOAST)(Jan) * Fix memory leak for expressions[memory](Tom?) ADMIN * More access control over who can create tables and use locks(Karel) * -Test syslog functionality * Convert remaining fprintf(stderr,...) to elog() * Allow elog() to return error codes, module name, file name, line number, not just messages * Allow international error message support and add error codes * -Unify configuration into one configuration file (Peter E) * -use setproctitle() if it exists for 'ps' display of status * Prevent initdb from running wrong version of postmaster/postgres TYPES * 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 o -Fix large object mapping scheme, own typeid or reltype(Peter) o -Not to stuff everything as files in a single directory, hash dirs o -Allow large object vacuuming o -Tables that start with xinv confused to be large objects * Add IPv6 capability to INET/CIDR types * Fix improper masking of some inet/cidr types [cidr] * Make a separate SERIAL type? * Store binary-compatible type information in the system * Add support for & operator * Allow LOCALE on a per-column basis, default to ASCII * Allow nulls in arrays * Allow arrays to be ORDER'ed * Support construction of array result values in expressions * Change foreign key constraint for array -> element to mean element in array * Remove Money type, add money formatting for decimal type * Declare typein/out functions in pg_proc with a special "C string" data type * Add non-large-object binary field * Functions returning sets don't really work right[function] * -Add hash for int8 (Tom) * SELECT col FROM tab WHERE numeric_col = 10.1 fails * Get BIT type working * Allow better handling of numeric constants, type conversion [typeconv] * Support multiple simultaneous character sets, per SQL92 * Reject character sequences those are not valid in their charset * Make functions more multi-byte aware, i.e. trim() * Make n of CHAR(n)/VARCHAR(n) the number of letters, not bytes * Update macaddr manufacturer numbers, or remove the function macaddr_manuf() * Add btree index support for reltime, tinterval, regproc, bit, varbit * Add rtree index support for line, lseg, path, point * Make file in/out interface to TOAST columns * SELECT cash_out(2) crashes because of opaque VIEWS * -Allow DISTINCT on views * -Allow views of aggregate columns * -Allow views with subselects * Create insert, update and delete rules for simple one table views * -Change elog for complex view ins|upd|del to "cannot {ins|upd|del} * Add the functionality for "with check option" clause of create view INDEXES * Allow CREATE INDEX zman_index ON test (date_trunc( 'day', zman ) datetime_ops) fails index can't store constant parameters * -Allow SQL function indexes * Add FILLFACTOR to index creation * Re-enable partial indexes * Allow inherited tables to inherit index COMMANDS * ALTER TABLE ADD COLUMN to inherited table put column in wrong place [inherit] * -Add ALTER TABLE ALTER COLUMN feature(Peter E) * Add ALTER TABLE DROP COLUMN feature [drop] * Add ALTER TABLE command to change table ownership (Mark H) * Add ALTER FUNCTION * Add ALTER TABLE ... DROP CONSTRAINT * Add ALTER USER command to change user db attributes * Automatically drop constraints/functions when object is dropped * Allow CLUSTER on all tables at once, and improve CLUSTER, loses NOT NULL specification, indexes, permissions, etc on table * Add SIMILAR TO to allow character classes, 'pg_[a-c]%' * Auto-destroy sequence on DROP of table with SERIAL(Ryan) * Allow LOCK TABLE tab1, tab2, tab3 so all tables locked in unison [lock] * Allow INSERT/UPDATE of system-generated oid value for a row * -Allow ESCAPE '\' at the end of LIKE for ANSI compliance (Thomas) * -Rewrite the LIKE handling by rewriting the user string with the supplied ESCAPE [like] * Allow RULE recompilation * -Support UNION/INTERSECT/EXCEPT in sub-selects * -Allow DELETE and UPDATE to use inheritance * Allow INSERT INTO my_table VALUES (a, b, c, DEFAULT, x, y, z, ...) * Allow BINARY option to SELECT, like we do with DECLARE * MOVE 0 should not move to end of cursor * Overhaul ACL (access control) code * Allow ORDER BY...LIMIT in INSERT INTO ... SELECT * Add SHOW command to display locks * Allow INSERT INTO tab (col1, ..) VALUES (val1, ..), (val2, ..) CLIENTS * Make NULL's come out at the beginning or end depending on the ORDER BY direction * Update reltuples from COPY command * Allow COPY to specify column names * fix array handling for ECPG * add pg_dump option to dump type names as standard ANSI types * -make pg_dump dump in oid order, so dependencies are resolved (Philip) * allow psql \d to show primary and foreign keys * allow psql \d to show temporary table schema * add XML interface capability * -Allow dumping of users/groups separately REFERENTIAL INTEGRITY * Add MATCH PARTIAL referential integrity * Foreign key does not check that columns referenced form a primary key or constrained by UNIQUE * Check that primary key exists at foreign key definition time * Prevent column dropping if column is used by foreign key * Propagate column or table renaming to foreign key constraints * Emit a warning at foreign key creation time if no UNIQUE index exists on referenced primary key attributes * Add deferred trigger queue file (Jan) * Allow oid to act as a foreign key * Implement dirty reads and use them in RI triggers EXOTIC FEATURES * Add sql3 recursive unions * Add the concept of dataspaces/tablespaces [tablespaces] * Add replication of distributed databases [replication] * Allow queries across multiple databases * Allow nested transactions (Vadim) * Allow INSERT/UPDATE to return new.col or old.col (Philip) * SQL*Net listener that makes PostgreSQL appear as an Oracle database to clients MISC * Increase identifier length(NAMEDATALEN) if small performance hit * Allow row re-use without vacuum(Vadim) * Create a background process for each database that runs while database is idle, finding superceeded rows, gathering stats and vacuuming * Add UNIQUE capability to non-btree indexes * Certain indexes will not shrink, i.e. oid indexes with many inserts(Vadim) * Restore unused oid's on backend exit if no one else has gotten oids * Have UPDATE/DELETE clean out indexes * Allow cursors to be DECLAREd/OPENed/CLOSEed outside transactions * Allow DELETE WHERE CURRENT OF cursor * -Transaction log, so re-do log can be on a separate disk by with after-row images(Vadim) [logging](Vadim) * Populate backend status area and write program to dump status data * Make oid use unsigned int more reliably, pg_atoi() * Put sort files in their own directory * Allow autocommit so always in a transaction block * Show location of syntax error in query [yacc] * -Redesign the function call interface to handle NULLs better[function](Tom) * Missing optimizer selectivities for date, r-tree, etc. [optimizer] * Overhaul bufmgr/lockmgr/transaction manager * -redesign UNION structures to have separarate target lists * -Allow multi-level query trees for INSERT INTO ... SELECT * Use IPC_EXCL when creating shared memory and semaphores * have pg_upgrade use pg_ctl to stop/start postmaster * Encrpyt passwords in pg_shadow table using MD5(Vince) * Use flock() to prevent multiple postmasters on the same port [flock] PERFORMANCE ----------- -FSYNC * -Allow transaction commits with rollback with no-fsync performance (Vadim) INDEXES * Use indexes to find min() and max() * Use index to restrict rows returned by multi-key index when used with non-consecutive keys or OR clauses, so fewer heap accesses * Allow SELECT * FROM tab WHERE int2col = 4 use int2col index, int8, float4, numeric/decimal too [optimizer] * Include heap CTID in btree index keys, remove equal-key cruft from btree * Use indexes with CIDR '<<' (contains) operator * Fix LIKE indexing optimization for non-ASCII locales CACHE * Cache most recent query plan(s) (Karel) [prepare] * Shared catalog cache, reduce lseek()'s by caching table size in shared area MISC * Allow compression of log and meta data * Allow char() not to use variable-sized header to reduce disk size * Do async I/O to do better read-ahead of data * Get faster regex() code from Henry Spencer when it is available * Use mmap() rather than SYSV shared memory(?) * Make oid use oidin/oidout not int4in/int4out in pg_type.h * Improve Subplan list handling * Allow Subplans to use efficient joins(hash, merge) with upper variable [subquery] * -use fmgr_info()/fmgr_faddr() instead of fmgr() calls in high-traffic places, like GROUP BY, UNIQUE, index processing, etc. * improve dynamic memory allocation by introducing tuple-context memory allocation [memory] * -In WHERE tab1.x=3 AND tab1.x=tab2.y, add tab2.y=3 * prevent labels from being output for stored rules (Tom) * allow configuration of maximum number of open files * Remove pg_listener index * -Redesign ANALYZE in VACUUM so it can be run separately without locks * Make ANALYZE a separate command * Gather more accurate dispersion statistics using indexes * Keep statistics about clustering of table rows [optimizer] * Improve statistics storage in pg_class [performance] * Improve VACUUM speed with indexes [vacuum] * Reduce VACUUM lock time by moving tuples with read lock, then write lock and truncate table [vacuum] * -BSD/OS does not support locale because there is no LC_MESSAGES (Bruce) * Add connection pooling [pool] * Allow persistent backends [persistent] * Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM ANALYZE, and CLUSTER SOURCE CODE ----------- * Add use of 'const' for variables in source tree * -Fix C optimizer problem where fmgr_ptr calls return different types (Tom) * Does Mariposa source contain any other bug fixes? * Remove SET KSQO option now that OR processing is improved(Tom) * -Use macros to define NT open() file parameters, remove NT-specific defines * -Change CURRENT to OLD internally for rules (Bruce) * replace the use of fprint(stderr, ...) with elog() in backend code --------------------------------------------------------------------------- Developers who have claimed items are: -------------------------------------- * Billy is Billy G. Allie * Brook is Brook Milligan * Bruce is Bruce Momjian * D'Arcy is D'Arcy J.M. Cain * Edmund is Edmund Mergl * Goran is Goran Thyni * Hiroshi is Hiroshi Inoue * Karel is Karel Zak * Jan is Jan Wieck * Marc is Marc Fournier * Massimo is Massimo Dal Zotto * Michael is Michael Meskes * Oleg is Oleg Bartunov * Peter is Peter T Mount * Philip is Philip Warner * Peter E is Peter Eisentraut * Ryan is Ryan Bradetich * Stephan is Stephan Szabo * Tatsuo is Tatsuo Ishii * Tom is Tom Lane * Thomas is Thomas Lockhart * TomH is Tom I Helbekkmo * Vadim is Vadim B. Mikheev