From bdd6c0a61fb29123d0a7dd9ac20740ad55c4a79f Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Wed, 29 Sep 1999 21:42:11 +0000 Subject: [PATCH] PostgreSQL TODO list

TODO list for PostgreSQL

Last updated: Tue Sep 28 00:34:21 EDT 1999

Current maintainer: Bruce Momjian (maillist@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 next release.

Names in brackets "[]" indicate more detailed information is available in
the directory pgsql/doc/TODO.detail/ under that name.

RELIABILITY

RESOURCES

Elog() does not free all its memory(Jan)
spinlock stuck problem when elog(FATAL) and elog(ERROR) inside bufmgr
Recover or force failure when disk space is exhausted

PARSER

Disallow inherited columns with the same name as new columns
INSERT INTO ... SELECT with AS columns matching result columns problem
SELECT pgclass FROM pgclass generates strange error
Alter TABLE ADD COLUMN does not honor DEFAULT, add CONSTRAINT
Do not allow bpchar column creation without length
-Select a[1] FROM test fails, it needs test.a[1]
-Array index references without table name cause problems [array]
Update table SET table.value = 3 fails(SQL standard says this is OK)
Creating index of TIMESTAMP & RELTIME fails, or rename to DATETIME(Thomas)
SELECT foo UNION SELECT foo is incorrectly simplified to SELECT foo
-INSERT ... SELECT ... GROUP BY groups by target columns not source columns
-CREATE TABLE test (a char(5) DEFAULT text '', b int4) fails on INSERT
UNION with LIMIT fails
Unique index on base column not honored on inserts from inherited table INSERT INTO inherit_table (uniqueindexcol) VALUES (dup) should fail [inherit]
CREATE TABLE x AS SELECT 1 UNION SELECT 2 fails
CREATE TABLE test(col char(2) DEFAULT user) fails in length restriction
mismatched types in CREATE TABLE ... DEFAULT causes problems [default]
SELECT ... UNION ... ORDER BY fails when sort expr not in result list
Be smarter about promoting types when UNION merges different data types
SELECT ... UNION ... GROUP BY fails if column types disagree
redesign INSERT ... SELECT to have two levels of target list
-select * from pg_class where oid in (0,-1)
have INTERSECT/EXCEPT prevent duplicates unless ALL is specified
prevent primary key of nine columns [primary]
SELECT COUNT('asdf') FROM pg_class WHERE oid=12 crashes
SELECT DISTINCT ON col1 col1 col2 FROM tab1 is broken [distinct]
-When using aggregates + GROUP BY, no rows in should yield no rows out

VIEWS

Views containing aggregates sometimes fail(Jan)
Views with spaces in view name fail when referenced
Creating view and inheriting the view causes view* to show duplicates(inherit)

MISC

User who can create databases can modify pg_database table
Plpgsql does not handle quoted mixed-case identifiers
Fix btree to give a useful elog when key > 1/2 (page - overhead)
pg_dump should preserve primary key information
plpgsql regression tests fail on BSD/OS

ENHANCEMENTS

URGENT

Add referential integrity(Jan?)[primary]
Add OUTER joins, left and right[outer](Thomas, Bruce)
Allow long tuples by chaining or auto-storing outside db (chaining,large objs)
Eliminate limits on query length
Fix memory leak for expressions?[memory](Tom?)
-Fix memory leak for aggregates?

ADMIN

Better interface for adding to pg_group
More access control over who can create tables and access the database
Test 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 [flock]
Add ability to specifiy location of lock/socket files [flock]

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, hash dirs
- Allow large object vacuuming
- Tables that start with xinv confused to be large objects
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
Allow LOCALE on a per-column basis, default to ASCII
Allow array on int8[]
Allow nulls in arrays
Allow arrays to be ORDER'ed
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
-Add index on NUMERIC/DECIMAL type
Make Absolutetime/Relativetime int4 because time_t can be int8 on some ports
Functions returning sets don't really work right[function]

VIEWS

Allow DISTINCT on views
Allow views of aggregate columns
Allow views with subselects

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
Allow indexing of LIKE with localle character sets
Allow indexing of more than eight columns

COMMANDS

ALTER TABLE ADD COLUMN to inherited table put column in wrong place [inherit]
Add ALTER TABLE DROP/ALTER COLUMN feature
Allow CLUSTER on all tables at once, and improve CLUSTER, loses NOT
NULL specification on table [cluster]
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
Allow INSERT/UPDATE of system-generated oid value for a row
Allow ESCAPE '\' at the end of LIKE for ANSI compliance [like]
Rewrite the LIKE handling by rewriting the user string with the supplied ESCAPE [like]
-Move LIKE index optimization handling to the optimizer
Allow RULE recompilation
Support UNION/INTERSECT/EXCEPT in sub-selects
Allow DELETE and UPDATE to use inheritance using tablename*

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 "" [null]

EXOTIC FEATURES

Add sql3 recursive unions
Add the concept of dataspaces
Add replication of distributed databases
Allow queries across multiple databases

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
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 by with after-row images(Vadim) [logging]
Populate backend status area and write program to dump status data
Make oid use unsigned int more reliably, pg_atoi()
Allow subqueries in target list
Put sort files, large objects in their own directory
Do 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]
Document/trigger/rule so changes to pgshadow recreate pgpwd [pg_shadow]
Missing optimizer selectivities for date, r-tree, etc. [optimizer]
Overhaul mdmgr/smgr to fix double unlinking and double opens, cleanup
Overhaul bufmgr/lockmgr/transaction manager
Add PL/Perl(Mark Hollomon)
Make postgres user have a password by default
Add configure test to check for C++ need for *.h and namespaces
Allow BLCKSZ <= 64k, not <= 32k
redesign UNION structures to have separarate target lists
Allow multi-level query trees for INSERT INTO ... SELECT

PERFORMANCE

FSYNC

-Allow transaction commits with rollback with no-fsync performance [fsync]
-Prevent fsync in SELECT-only queries

INDEXES

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
-Convert function(constant) into a constant for index use
Allow LIMIT ability on single-table queries that have no ORDER BY to use a matching index [limit]
Improve LIMIT processing by using index to limit rows processed [limit]
Have optimizer take LIMIT into account when considering index scans [limit]
Make index creation use psort code, because it is now faster(Vadim)
Allow creation of sort temp tables > 1 Gig
Create more system table indexes for faster cache lookups
fix indexscan() so it does leak memory by not requiring caller to free
Improve btbinsrch() to handle equal keys better, remove btfirsteq()(Tom)
Allow SELECT * FROM tab WHERE int2col = 4 use int2col index, int8, float4, numeric/decimal too [optimizer]
-Allow optimizer to prefer plans that match ORDER BY

CACHE

Cache most recent query plan(s) [prepare]
Shared catalog cache, reduce lseek()'s by caching table size in shared area
elog() flushes cache, try invalidating just entries from current xact, perhaps using invalidation cache

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
-Fix memory exhaustion when using many OR's [cnfify]
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
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]
fix memory leak in cache code when non-existant table is referenced
In WHERE tab1.x=3 AND tab1.x=tab2.y, add tab2.y=3
pass atttypmod through parser in more cases [atttypmod]
remove duplicate type in/out functions for disk and net
Allow persistent backends [persistent]
Misc [performance]

SOURCE CODE

Add use of 'const' for varibles in source tree
Fix C optimizer problem where fmgr_ptr calls return different types [alpha]
-Add needed includes and removed unneeded include files(Bruce)
Make configure --enable-debug add -g on compile line
Does Mariposa source contain any other bug fixes?
Remove SET KSQO option if OR processing is improved(Tom)

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@postgresql.org>
Oleg is Oleg Bartunov <oleg@sai.msu.su>
Peter is Peter T Mount <peter@retep.org.uk>
Ryan is Ryan Bradetich <rbrad@hpb50023.boi.hp.com>
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>

--- doc/TODO | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/doc/TODO b/doc/TODO index d35938afe9..9085dbb923 100644 --- a/doc/TODO +++ b/doc/TODO @@ -117,7 +117,7 @@ TYPES * 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 -* Add index on NUMERIC/DECIMAL type +* -Add index on NUMERIC/DECIMAL type * Make Absolutetime/Relativetime int4 because time_t can be int8 on some ports * Functions returning sets don't really work right[function] -- 2.40.0