TODO 30.4 KB
Newer Older
B
Bruce Momjian 已提交
1
TODO list for PostgreSQL
B
Bruce Momjian 已提交
2
========================
3
#A dash (-) marks changes that will appear in the upcoming 8.0 release.#
4 5

Bracketed items "[]" have more detail.
M
Marc G. Fournier 已提交
6

B
Bruce Momjian 已提交
7
Current maintainer:	Bruce Momjian (pgman@candle.pha.pa.us)
B
Add:  
Bruce Momjian 已提交
8
Last updated:		Mon Aug  9 18:39:14 EDT 2004
M
Marc G. Fournier 已提交
9

B
Bruce Momjian 已提交
10
The most recent version of this document can be viewed at the PostgreSQL web site, http://www.PostgreSQL.org.
B
Bruce Momjian 已提交
11

12
Remove items before beta?
B
Bruce Momjian 已提交
13

14 15
Urgent
======
B
Bruce Momjian 已提交
16

B
Bruce Momjian 已提交
17 18
* Point-in-time data recovery using backup and write-ahead log,
* Create native Win32 port, http://momjian.postgresql.org/main/writings/pgsql/project/win32.html
B
Bruce Momjian 已提交
19

B
Bruce Momjian 已提交
20

21 22
Administration
==============
B
Bruce Momjian 已提交
23

24
* -Incremental backups
B
Bruce Momjian 已提交
25 26
* Remove behavior of postmaster -o after making postmaster/postgres
  flags unique
B
Done:  
Bruce Momjian 已提交
27
* -Allow configuration files to be specified in a different directory
B
Add:  
Bruce Momjian 已提交
28
* Allow limits on per-db/user connections
B
Add:  
Bruce Momjian 已提交
29 30
* Add group object ownership, so groups can rename/drop/grant on objects,
  so we can implement roles
B
Done:  
Bruce Momjian 已提交
31
* -Add the concept of dataspaces/tablespaces (Gavin)
B
Done:  
Bruce Momjian 已提交
32
* -Allow logging of only data definition(DDL), or DDL and modification statements
B
Done:  
Bruce Momjian 已提交
33
* -Allow log lines to include session-level information, like database and user
B
Add:;  
Bruce Momjian 已提交
34
* Allow server log information to be output as INSERT statements
35 36 37 38

  This would allow server log information to be easily loaded into
  a database for analysis.

39
* Prevent default re-use of sysids for dropped users and groups
40 41 42 43 44

  Currently, if a user is removed while he still owns objects, a new
  user given might be given their user id and inherit the
  previous users objects.

45
* Prevent dropping user that still owns objects, or auto-drop the objects
46 47 48 49 50
* Allow pooled connections to list all prepared queries

  This would allow an application inheriting a pooled connection to know
  the queries prepared in the current session.

B
Add:  
Bruce Momjian 已提交
51
* Allow major upgrades without dump/reload, perhaps using pg_upgrade
52 53 54 55
* Have SHOW ALL and pg_settings show descriptions for server-side variables
* -Allow external interfaces to extend the GUC variable set
* Allow GRANT/REVOKE permissions to be given to all schema objects with one 
  command
B
Bruce Momjian 已提交
56
* Remove unreferenced table files created by transactions that were
B
Bruce Momjian 已提交
57
  in-progress when the server terminated abruptly
B
Add:  
Bruce Momjian 已提交
58
* Allow reporting of which objects are in which tablespaces
59 60 61 62 63 64 65

  This item is difficult because a tablespace can contain objects from
  multiple databases. There is a server-side function that returns the
  databases which use a specific tablespace, so this requires a tool
  that will call that function and connect to each database to find the
  objects in each database for that tablespace.

B
Add:  
Bruce Momjian 已提交
66
* Allow database recovery where tablespaces can't be created
67 68 69 70 71 72

  When a pg_dump is restored, all tablespaces will attempt to be created
  in their original locations. If this fails, the user must be able to 
  adjust the restore process.

* Add "include file" functionality in postgresql.conf
B
Add:  
Bruce Momjian 已提交
73
* Add session start time and last statement time to pg_stat_activity
74 75
* Allow server logs to be remotely read using SQL commands
* Allow server configuration parameters to be remotely modified
B
Add:  
Bruce Momjian 已提交
76
* Allow administrators to safely terminate individual sessions
77 78 79 80 81

  Right now, SIGTERM will terminate a session, but it is treated as
  though the postmaster has paniced and shared memory might not be
  cleaned up properly.  A new signal is needed for safe termination.

B
Modify:  
Bruce Momjian 已提交
82
* Un-comment all variables in postgresql.conf
B
Bruce Momjian 已提交
83

B
Modify:  
Bruce Momjian 已提交
84 85
  By not showing commented-out variables, we discourage people from 
  thinking that re-commenting a variable returns it to its default.
B
Bruce Momjian 已提交
86

87 88 89 90 91 92
* Allow point-in-time recovery to archive partially filled write-ahead 
  logs

  Currently only full WAL files are archived. This means that the most
  recent transactions aren't available for recovery in case of a disk
  failure.
B
Add:  
Bruce Momjian 已提交
93

B
Add:  
Bruce Momjian 已提交
94 95
* Create dump tool for write-ahead logs for use in determining
  transaction id for point-in-time recovery
B
Bruce Momjian 已提交
96 97
* Improve replication solutions
	o Automatic failover
98 99 100 101 102

	The proper solution to this will probably the use of a master/slave
	replication solution like Sloney and a connection pooling tool like
	pgpool.

B
Bruce Momjian 已提交
103
	o Load balancing
104 105 106 107 108

	You can use any of the master/slave replication servers to use a
	standby server for data warehousing. To allow read/write queries to
	multiple servers, you need multi-master replication like pgcluster.

B
Bruce Momjian 已提交
109
	o Allow replication over unreliable or non-persistent links
B
Add:  
Bruce Momjian 已提交
110

B
Bruce Momjian 已提交
111

112 113
Data Types
==========
B
Bruce Momjian 已提交
114 115

* Remove Money type, add money formatting for decimal type
B
Bruce Momjian 已提交
116
* -Change factorial to return a numeric (Gavin)
B
Add:  
Bruce Momjian 已提交
117
* Change NUMERIC to enforce the maximum precision, and increase it
118 119
* Add function to return compressed length of TOAST data values
* Allow INET subnet tests with non-constants to be indexed
B
Update:  
Bruce Momjian 已提交
120
* Add transaction_timestamp(), statement_timestamp(), clock_timestamp() functionality
121 122 123 124 125 126 127 128 129

  Current CURRENT_TIMESTAMP returns the start time of the current
  transaction, and gettimeofday() returns the wallclock time. This will
  make time reporting more consistent and will allow reporting of
  the statement start time.

* Have sequence dependency track use of DEFAULT sequences,
  seqname.nextval (?)
* Disallow changing default expression of a SERIAL column (?)
B
Add:  
Bruce Momjian 已提交
130
* Allow infinite dates just like infinite timestamps
B
Bruce Momjian 已提交
131 132
* -Allow pg_dump to dump sequences using NO_MAXVALUE and NO_MINVALUE
* -Prevent whole-row references from leaking memory, e.g. SELECT COUNT(tab.*)
B
Bruce Momjian 已提交
133
* Have initdb set DateStyle based on locale?
B
Add:  
Bruce Momjian 已提交
134
* Add pg_get_acldef(), pg_get_typedefault(), and pg_get_attrdef()
135
* Allow to_char to print localized month names
B
Add:  
Bruce Momjian 已提交
136
* Allow functions to have a search path specified at creation time
B
Bruce Momjian 已提交
137
* -Make LENGTH() of CHAR() not count trailing spaces
B
Add:  
Bruce Momjian 已提交
138
* Allow substring/replace() to get/set bit values
B
Add:  
Bruce Momjian 已提交
139
* Add GUC variable to allow output of interval values in ISO8601 format
140
* -Support composite types as table columns
B
Add:  
Bruce Momjian 已提交
141
* Fix data types where equality comparison isn't intuitive, e.g. box
B
Add:  
Bruce Momjian 已提交
142

B
Bruce Momjian 已提交
143

144
* ARRAYS
B
Bruce Momjian 已提交
145
	o Allow nulls in arrays
B
Bruce Momjian 已提交
146
	o Allow MIN()/MAX() on arrays
B
Bruce Momjian 已提交
147
	o Delay resolution of array expression type so assignment coercion 
148
	  can be performed on empty array expressions
B
Bruce Momjian 已提交
149 150 151
	o Modify array literal representation to handle array index lower bound
	  of other than one

B
Bruce Momjian 已提交
152

B
Bruce Momjian 已提交
153
* BINARY DATA
154
	o Improve vacuum of large objects, like /contrib/vacuumlo (?)
B
Bruce Momjian 已提交
155
	o Add security checking for large objects
156 157 158 159

	Currently large objects entries do not have owners. Permissions can
	only be set at the pg_largeobject table level.

B
Bruce Momjian 已提交
160
	o Auto-delete large objects when referencing row is deleted
B
Bruce Momjian 已提交
161

162 163 164 165
	o Allow read/write into TOAST values like large objects

	This requires the TOAST column to be stored EXTERNAL.

166

167 168
Multi-Language Support
======================
B
Bruce Momjian 已提交
169

170
* Add NCHAR (as distinguished from ordinary varchar),
B
Update:  
Bruce Momjian 已提交
171
* Allow locale to be set at database creation
172 173 174 175 176 177 178 179

  Currently locale can only be set during initdb.

* Allow encoding on a per-column basis

  Right now only one encoding is allowed per database.

* Optimize locale to have minimal performance impact when not used
B
Bruce Momjian 已提交
180
* Support multiple simultaneous character sets, per SQL92
181 182 183 184
* Improve Unicode combined character handling (?)
* Add octet_length_server() and octet_length_client()
* Make octet_length_client() the same as octet_length()?
* -Prevent mismatch of frontend/backend encodings from converting bytea
B
Added:  
Bruce Momjian 已提交
185
  data from being interpreted as encoded strings
B
Done:  
Bruce Momjian 已提交
186
* -Fix upper()/lower() to work for multibyte encodings
B
Add:  
Bruce Momjian 已提交
187

188

189 190
Views / Rules
=============
B
Bruce Momjian 已提交
191

B
Bruce Momjian 已提交
192
* Automatically create rules on views so they are updateable, per SQL92 [view]
B
Bruce Momjian 已提交
193
* Add the functionality for WITH CHECK OPTION clause of CREATE VIEW
B
Bruce Momjian 已提交
194
* Allow NOTIFY in rules involving conditionals
B
Bruce Momjian 已提交
195
* Have views on temporary tables exist in the temporary namespace
B
Add:  
Bruce Momjian 已提交
196
* Allow temporary views on non-temporary tables
B
Bruce Momjian 已提交
197
* Allow RULE recompilation
198

B
Add:  
Bruce Momjian 已提交
199

200 201
Indexes
=======
B
Bruce Momjian 已提交
202

203
* -Order duplicate index entries on creation by ctid for faster heap lookups
B
Bruce Momjian 已提交
204 205
* Allow inherited tables to inherit index, UNIQUE constraint, and primary
  key, foreign key  [inheritance]
206 207 208 209 210 211 212
* UNIQUE INDEX on base column not honored on inserts/updates from
  inherited table:  INSERT INTO inherit_table (unique_index_col) VALUES
  (dup) should fail [inheritance]

  The main difficulty with this item is the problem of creating an index
  that can spam more than one table.

B
Bruce Momjian 已提交
213
* Add UNIQUE capability to non-btree indexes
B
Bruce Momjian 已提交
214
* Add rtree index support for line, lseg, path, point
215 216 217 218 219 220
* Use indexes for MIN() and MAX()

  MIN/MAX queries can already be rewritten as SELECT col FROM tab ORDER
  BY col {DESC} LIMIT 1. Completing this item involves making this
  transformation automatically.

B
Bruce Momjian 已提交
221
* Use index to restrict rows returned by multi-key index when used with
222 223 224 225 226 227 228
  non-consecutive keys to reduce heap accesses

  For an index on col1,col2,col3, and a WHERE clause of col1 = 5 and
  col3 = 9, spin though the index checking for col1 and col3 matches,
  rather than just col1

* -Be smarter about insertion of already-ordered data into btree index
B
Bruce Momjian 已提交
229
* Prevent index uniqueness checks when UPDATE does not modify the column
230 231 232 233 234 235 236 237 238 239 240

  Uniqueness (index) checks are done when updating a column even if the
  column is not modified by the UPDATE.

* Fetch heap pages matching index entries in sequential order [performance]

  Rather than randomly accessing heap pages based on index entries, mark
  heap pages needing access in a bitmap and do the lookups in sequential
  order. Another method would be to sort heap ctids matching the index
  before accessing the heap rows.

B
Update:  
Bruce Momjian 已提交
241
* Use bitmaps to combine existing indexes [performance]
242 243 244 245 246

  Bitmap indexes allow single indexed columns to be combined to
  dynamically create a composite index to match a specific query. Each
  index is a bitmap, and the bitmaps are AND'ed or OR'ed to be combined.

B
Bruce Momjian 已提交
247
* Allow use of indexes to search for NULLs
248 249 250

  One solution is to create a partial index on an IS NULL expression.

B
Bruce Momjian 已提交
251
* -Allow SELECT * FROM tab WHERE int2col = 4 to use int2col index, int8,
B
Bruce Momjian 已提交
252
  float4, numeric/decimal too
B
Reword:  
Bruce Momjian 已提交
253
* Add concurrency to GIST
B
Reword:  
Bruce Momjian 已提交
254
* Pack hash index buckets onto disk pages more efficiently
B
Bruce Momjian 已提交
255

256 257 258 259
  Currently no only one hash bucket can be stored on a page. Ideally
  several hash buckets could be stored on a single page and greater
  granularity used for the hash algorithm.

B
Bruce Momjian 已提交
260

261 262
Commands
========
B
Bruce Momjian 已提交
263

264
* Add BETWEEN ASYMMETRIC/SYMMETRIC
B
Add:  
Bruce Momjian 已提交
265
* Change LIMIT/OFFSET to use int8
B
Bruce Momjian 已提交
266
* CREATE TABLE AS can not determine column lengths from expressions [atttypmod]
267 268
* Allow UPDATE to handle complex aggregates [update] (?)
* -Allow command blocks to ignore certain types of errors
B
Added:  
Bruce Momjian 已提交
269
* Allow backslash handling in quoted strings to be disabled for portability
270 271 272 273 274 275 276 277 278 279 280

  The use of C-style backslashes (.e.g. \n, \r) in quoted strings is not
  SQL-spec compliant, so allow such handling to be disabled.

* Allow DELETE to handle table aliases for self-joins [delete]

  There is no way to specify use a table alias for the deleted table in
  the DELETE WHERE clause because there is no FROM clause. Various
  syntax extensions to add a FROM clause have been discussed. UPDATE
  already has such an optional FROM clause.

B
Add:  
Bruce Momjian 已提交
281
* Add CORRESPONDING BY to UNION/INTERSECT/EXCEPT
282
* Allow REINDEX to rebuild all database indexes, remove /contrib/reindex
B
Add:  
Bruce Momjian 已提交
283
* Add ROLLUP, CUBE, GROUPING SETS options to GROUP BY
284 285 286
* Add a schema option to createlang
* -Allow savepoints / nested transactions [transactions] (Alvaro)
* -Use nested transactions to prevent syntax errors from aborting a transaction
B
Add:  
Bruce Momjian 已提交
287
* Allow UPDATE tab SET ROW (col, ...) = (...) for updating multiple columns
288 289
* Allow SET CONSTRAINTS to be qualified by schema/table name
* -Prevent COMMENT ON DATABASE from using a database name
B
Done:  
Bruce Momjian 已提交
290
* -Add NO WAIT LOCKs
B
Add:  
Bruce Momjian 已提交
291
* Allow TRUNCATE ... CASCADE/RESTRICT
B
Add:  
Bruce Momjian 已提交
292
* Allow PREPARE of cursors
293 294 295 296 297 298 299
* Allow PREPARE to automatically determine parameter types based on the SQL 
  statement
* Allow LISTEN/NOTIFY to store info in memory rather than tables?

  Currently LISTEN/NOTIFY information is stored in pg_listener. Storing
  such information in memory would improve performance.

B
Done:  
Bruce Momjian 已提交
300
* -COMMENT ON [ CAST | CONVERSION | OPERATOR CLASS | LARGE OBJECT | LANGUAGE ] 
B
Update:  
Bruce Momjian 已提交
301
  (Christopher) 
B
Added:  
Bruce Momjian 已提交
302
* Dump large object comments in custom dump format
B
Bruce Momjian 已提交
303
* Add optional textual message to NOTIFY
304 305 306 307 308

  This would allow an informational message to be added to the notify
  message, perhaps indicating the row modified or other custom
  information.

B
Bruce Momjian 已提交
309
* -Allow more ISOLATION LEVELS to be accepted
B
Add:  
Bruce Momjian 已提交
310
* Allow CREATE TABLE foo (f1 INT CHECK (f1 > 0) CHECK (f1 < 10)) to work
311 312 313 314 315 316 317 318 319
  by searching for non-conflicting constraint names, and prefix with
  table name?
* Use more reliable method for CREATE DATABASE to get a consistent copy
  of db?

  Currently the system uses the operating system COPY command to create
  new database.

* Add C code to copy directories for use in creating new databases
B
Done:  
Bruce Momjian 已提交
320
* -Have psql \dn show only visible temp schemas using current_schemas()
B
Done:  
Bruce Momjian 已提交
321
* -Have psql '\i ~/<tab><tab>' actually load files it displays from home dir
322 323
* Ignore temporary tables from other sessions when processing
  inheritance?
B
Bruce Momjian 已提交
324
* -Add GUC setting to make created tables default to WITHOUT OIDS
325 326 327
* Have pg_ctl look at PGHOST in case it is a socket directory?
* Allow column-level GRANT/REVOKE privileges
* Add a session mode to warn about non-standard SQL usage in queries
B
Bruce Momjian 已提交
328
* Add MERGE command that does UPDATE/DELETE, or on failure, INSERT (rules, triggers?)
B
Add:  
Bruce Momjian 已提交
329
* Add ON COMMIT capability to CREATE TABLE AS SELECT
B
Add:  
Bruce Momjian 已提交
330
* Add NOVICE output level for helpful messages like automatic sequence/index creation
B
Add:  
Bruce Momjian 已提交
331
* Add COMMENT for tablespaces
B
Add:  
Bruce Momjian 已提交
332

B
Bruce Momjian 已提交
333
* ALTER
B
Done:  
Bruce Momjian 已提交
334 335
	o -ALTER TABLE ADD COLUMN does not honor DEFAULT and non-CHECK CONSTRAINT
	o -ALTER TABLE ADD COLUMN column DEFAULT should fill existing
B
Bruce Momjian 已提交
336
	  rows with DEFAULT value
B
Done:  
Bruce Momjian 已提交
337
	o -ALTER TABLE ADD COLUMN column SERIAL doesn't create sequence because
B
Bruce Momjian 已提交
338
          of the item above
339
	o Have ALTER TABLE RENAME rename SERIAL sequence names
B
Done:  
Bruce Momjian 已提交
340
	o -Allow ALTER TABLE to modify column lengths and change to binary
B
Add:  
Bruce Momjian 已提交
341
	  compatible types
342
	o -Add ALTER DATABASE ... OWNER TO newowner
B
Add:  
Bruce Momjian 已提交
343
	o Add ALTER DOMAIN TYPE
B
Add:  
Bruce Momjian 已提交
344
	o Allow ALTER TABLE ... ALTER CONSTRAINT ... RENAME
B
Add:  
Bruce Momjian 已提交
345
	o Allow ALTER TABLE to change constraint deferrability and actions
B
Add:  
Bruce Momjian 已提交
346
	o Disallow dropping of an inherited constraint
347 348 349 350 351 352 353 354 355 356 357
	o Allow objects to be moved to different schemas
	o Allow ALTER TABLESPACE to move to different directories
	o Allow databases, schemas, and indexes to be moved to different 
	  tablespaces
	o Allow moving system tables to other tablespaces, where possible

	Currently non-global system tables must be in the default database
	schema. Global system tables can never be moved.

	o -Add ALTER DOMAIN, AGGREGATE, CONVERSION ... OWNER TO
	o -Add ALTER SEQUENCE ... OWNER TO
B
Bruce Momjian 已提交
358

B
Bruce Momjian 已提交
359
* CLUSTER
B
Bruce Momjian 已提交
360
	o Automatically maintain clustering on a table
361 362 363 364 365 366

	This would require some background daemon to restore clustering
	during periods of low usage. It might also require tables to be only
	paritally filled for easier reorganization.

	o -Add ALTER TABLE table SET WITHOUT CLUSTER (Christopher)
B
Add:  
Bruce Momjian 已提交
367
	o Add default clustering to system tables
B
Bruce Momjian 已提交
368

369 370 371
	To do this, determine the ideal cluster index for each system
	table and set the cluster setting during initdb.

B
Bruce Momjian 已提交
372
* COPY
B
Done:  
Bruce Momjian 已提交
373
	o -Allow dump/load of CSV format
374 375 376 377 378 379 380
	o Allow COPY to report error lines and continue
	
	This requires the use of a savepoint before each COPY line is
	processed, with ROLLBACK on COPY failure.

	o Allow COPY to understand \x as a hex byte
	o Have COPY return the number of rows loaded/unloaded (?)
B
Bruce Momjian 已提交
381

B
Bruce Momjian 已提交
382
* CURSOR
383 384 385 386 387 388 389 390 391 392 393 394 395 396
	o Allow UPDATE/DELETE WHERE CURRENT OF cursor
	
	This requires using the row ctid to map cursor rows back to the
	original heap row. This become more complicated if WITH HOLD cursors
	are to be supported because WITH HOLD cursors have a copy of the row
	and no FOR UPDATE lock.

	o Prevent DROP TABLE from dropping a row referenced by its own open
	  cursor (?)

	o Allow pooled connections to list all open WITH HOLD cursors

	Because WITH HOLD cursors exist outside transactions, this allows
	them to be listed so they can be closed.
B
Bruce Momjian 已提交
397

B
Bruce Momjian 已提交
398
* INSERT
399
	o Allow INSERT/UPDATE of the system-generated oid value for a row
B
Bruce Momjian 已提交
400
	o Allow INSERT INTO tab (col1, ..) VALUES (val1, ..), (val2, ..)
401 402 403 404 405
	o Allow INSERT/UPDATE ... RETURNING new.col or old.col
	
	This is useful for returning the auto-generated key for an INSERT.
	One complication is how to handle rules that run as part of
	the insert.
B
Bruce Momjian 已提交
406

B
Bruce Momjian 已提交
407
* SHOW/SET
B
Bruce Momjian 已提交
408
	o Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM
B
Bruce Momjian 已提交
409
	  ANALYZE, and CLUSTER
410 411 412 413 414 415 416 417
	o Add SET PATH for schemas (?)

	This is basically the same as SET search_path.
	 
	o Prevent conflicting SET options from being set

	This requires a checking function to be called after the server
	configuration file is read.
B
Bruce Momjian 已提交
418

B
Bruce Momjian 已提交
419
* SERVER-SIDE LANGUAGES
420 421 422 423
	o Allow PL/PgSQL's RAISE function to take expressions (?)

	Currently only constants are supported.

B
Bruce Momjian 已提交
424
	o Change PL/PgSQL to use palloc() instead of malloc()
B
Done:  
Bruce Momjian 已提交
425
	o -Allow Java server-side programming
426 427 428 429 430 431 432 433
	o Handle references to temporary tables that are created, destroyed, 
	  then recreated during a session, and EXECUTE is not used
	  
	This requires the cached PL/PgSQL byte code to be invalidated when
	an object referenced in the function is changed.

    o Fix PL/pgSQL RENAME to work on variables other than OLD/NEW
	o Improve PL/PgSQL exception handling using savepoints
B
Bruce Momjian 已提交
434
	o -Allow PL/pgSQL parameters to be specified by name and type during definition
B
Bruce Momjian 已提交
435
	o Allow function parameters to be passed by name,
B
Added:  
Bruce Momjian 已提交
436
	  get_employee_salary(emp_id => 12345, tax_year => 2001)
437 438
	o Add Oracle-style packages
	o Add table function support to pltcl, plperl, plpython (?)
B
Add:  
Bruce Momjian 已提交
439
	o Allow PL/pgSQL to name columns by ordinal position, e.g. rec.(3)
B
Add:  
Bruce Momjian 已提交
440
	o Allow PL/pgSQL EXECUTE query_var INTO record_var;
B
Bruce Momjian 已提交
441
	o Add capability to create and call PROCEDURES
B
Add:  
Bruce Momjian 已提交
442
	o Allow PL/pgSQL to handle %TYPE arrays, e.g. tab.col%TYPE[]
B
Bruce Momjian 已提交
443

B
Add:  
Bruce Momjian 已提交
444

445 446
Clients
=======
B
Bruce Momjian 已提交
447

448 449 450 451 452 453
* Add XML output to pg_dump and COPY

  We already allow XML to be stored in the database, and XPath queries
  can be used on that data using /contrib/xml2. It also supports XSLT
  transformations.
    
B
Bruce Momjian 已提交
454
* -Allow psql \du to show users, and add \dg for groups
B
Add:  
Bruce Momjian 已提交
455
* Add a libpq function to support Parse/DescribeStatement capability
456
* Prevent libpq's PQfnumber() from lowercasing the column name (?)
B
Done:  
Bruce Momjian 已提交
457
* -Allow pg_dump to dump CREATE CONVERSION (Christopher)
B
Done:  
Bruce Momjian 已提交
458
* -Make pg_restore continue after errors, so it acts more like pg_dump scripts
B
Bruce Momjian 已提交
459
* Have psql show current values for a sequence
B
Add:  
Bruce Momjian 已提交
460
* Allow pg_dumpall to use non-text output formats
B
Add:  
Bruce Momjian 已提交
461
* Have pg_dump use multi-statement transactions for INSERT dumps
B
Bruce Momjian 已提交
462
* Move psql backslash database information into the backend, use mnemonic
B
Add:  
Bruce Momjian 已提交
463
  commands? [psql]
464 465 466 467

  This would allow non-psql clients to pull the same information out of
  the database as psql.

B
Add:  
Bruce Momjian 已提交
468
* Allow pg_dump to use multiple -t and -n switches
469 470 471

  This should be done by allowing a '-t schema.table' syntax.

B
Add:  
Bruce Momjian 已提交
472
* Fix oid2name and dbsize for tablespaces
473
* Consistently display privilege information for all objects in psql
B
Bruce Momjian 已提交
474

475
* ECPG (?)
M
Michael Meskes 已提交
476
	o Docs
477 478 479 480 481 482 483

	Document differences between ecpg and the SQL standard and
	information about the Informix-compatibility module.

	o -Implement SET DESCRIPTOR
	o Solve cardinality > 1 for input descriptors / variables (?)
	o Improve error handling (?)
B
Bruce Momjian 已提交
484
	o Add a semantic check level, e.g. check if a table really exists
B
Bruce Momjian 已提交
485
	o fix handling of DB attributes that are arrays
B
Bruce Momjian 已提交
486
	o Use backend PREPARE/EXECUTE facility for ecpg where possible
B
Update:  
Bruce Momjian 已提交
487
	o Implement SQLDA
M
Michael Meskes 已提交
488 489
	o Fix nested C comments
	o sqlwarn[6] should be 'W' if the PRECISION or SCALE value specified
490
	o Make SET CONNECTION thread-aware, non-standard?
491
	o Allow multidimensional arrays
B
Bruce Momjian 已提交
492

B
Bruce Momjian 已提交
493

494 495
Referential Integrity
=====================
B
Bruce Momjian 已提交
496

B
Bruce Momjian 已提交
497
* Add MATCH PARTIAL referential integrity
498 499 500 501 502 503 504
* Add deferred trigger queue file

  Right now all deferred trigger information is stored in backend
  memory.  This could exhaust memory for very large trigger queues.
  This item involves dumping large queues into files.

* Implement dirty reads or shared row locks and use them in RI triggers (?)
B
Bruce Momjian 已提交
505
* Enforce referential integrity for system tables
B
Bruce Momjian 已提交
506
* Change foreign key constraint for array -> element to mean element
507 508
  in array (?)
* Allow DEFERRABLE UNIQUE constraints (?)
B
Add:  
Bruce Momjian 已提交
509
* Allow triggers to be disabled [trigger]
510 511 512 513

  Currently the only way to disable triggers is to modify the system
  tables.

514
* With disabled triggers, allow pg_dump to use ALTER TABLE ADD FOREIGN KEY
515 516 517 518

  If the dump is known to be valid, allow foreign keys to be added
  without revalidating the data.

B
Bruce Momjian 已提交
519
* Allow statement-level triggers to access modified rows
520
* Support triggers on columns
B
Add:  
Bruce Momjian 已提交
521 522
* Have AFTER triggers execute after the appropriate SQL statement in a 
  function, not at the end of the function
B
Done:  
Bruce Momjian 已提交
523
* -Print table names with constraint names in error messages, or make constraint
B
Add:  
Bruce Momjian 已提交
524
  names unique within a schema
B
Done:  
Bruce Momjian 已提交
525
* -Issue NOTICE if foreign key data requires costly test to match primary key
B
Add:  
Bruce Momjian 已提交
526
* Remove CREATE CONSTRAINT TRIGGER
527 528 529 530

  This was used in older releases to dump referential integrity
  constraints.

B
Add:  
Bruce Momjian 已提交
531
* Allow AFTER triggers on system tables
B
Add:  
Bruce Momjian 已提交
532

533 534 535 536 537
  System tables are modified in many places in the backend without going
  through the executor and therefore not causing triggers to fire. To
  complete this item, the functions that modify system tables will have
  to fire triggers.

B
Bruce Momjian 已提交
538

539 540
Dependency Checking
===================
B
Bruce Momjian 已提交
541

542
* Flush cached query plans when the dependent objects change
B
Done:  
Bruce Momjian 已提交
543
* -Use dependency information to dump data in proper order
B
Bruce Momjian 已提交
544
* -Have pg_dump -c clear the database using dependency information
B
Add:  
Bruce Momjian 已提交
545
* Track dependencies in function bodies and recompile/invalidate
546

B
Add:  
Bruce Momjian 已提交
547

548 549
Exotic Features
===============
550

551 552 553 554 555 556 557 558
* Add SQL99 WITH clause to SELECT
* Add SQL99 WITH RECURSIVE to SELECT
* Add pre-parsing phase that converts non-ANSI syntax to supported
  syntax

  This could allow SQL written for other databases to run without
  modification.

B
Bruce Momjian 已提交
559
* Allow plug-in modules to emulate features from other databases
B
Bruce Momjian 已提交
560
* SQL*Net listener that makes PostgreSQL appear as an Oracle database
B
Bruce Momjian 已提交
561
  to clients
562 563 564 565 566 567 568 569 570 571 572 573
* Allow queries across databases or servers with transaction
  semantics
	
  Right now contrib/dblink can be used to issue such queries except it
  does not have locking or transaction semantics. Two-phase commit is
  needed to enable transaction semantics.

* Add two-phase commit

  This will involve adding a way to respond to commit failure by either
  taking the server into offline/readonly mode or notifying the
  administrator
574

B
Bruce Momjian 已提交
575

B
Bruce Momjian 已提交
576
PERFORMANCE
577 578
===========

B
Bruce Momjian 已提交
579

580 581
Fsync
=====
B
Bruce Momjian 已提交
582

583
* Improve commit_delay handling to reduce fsync()
B
Bruce Momjian 已提交
584
* Determine optimal fdatasync/fsync, O_SYNC/O_DSYNC options
585 586
* Allow multiple blocks to be written to WAL with one write()
* Add an option to sync() before fsync()'ing checkpoint files
B
Bruce Momjian 已提交
587

B
Bruce Momjian 已提交
588

589 590
Cache
=====
B
Bruce Momjian 已提交
591
* Add free-behind capability for large sequential scans [fadvise]
B
Bruce Momjian 已提交
592
* Consider use of open/fcntl(O_DIRECT) to minimize OS caching
593 594 595 596 597 598 599 600 601 602 603 604 605
* Cache last known per-tuple offsets to speed long tuple access

  While column offsets are already cached, the cache can not be used if
  the tuple has NULLs or TOAST columns because these values change the
  typical column offsets. Caching of such offsets could be accomplished
  by remembering the previous offsets and use them again if the row has
  the same pattern.

* Speed up COUNT(*)

  We could use a fixed row count and a +/- count to follow MVCC
  visibility rules, or a single cached value could be used and
  invalidated if anyone modifies the table. [count]
B
Bruce Momjian 已提交
606

607

608 609
Vacuum
======
B
Bruce Momjian 已提交
610

611 612 613 614 615
* Improve speed with indexes

  For large table adjustements during vacuum, it is faster to reindex
  rather than update the index.

B
Bruce Momjian 已提交
616
* Reduce lock time by moving tuples with read lock, then write
B
Bruce Momjian 已提交
617
  lock and truncate table
618 619 620 621 622 623

  Moved tuples are invisible to other backends so they don't require a
  write lock. However, the read lock promotion to write lock could lead
  to deadlock situations.

* -Provide automatic running of vacuum in the background in backend
B
Bruce Momjian 已提交
624
  rather than in /contrib (Matthew)
B
Add:  
Bruce Momjian 已提交
625
* Allow free space map to be auto-sized or warn when it is too small
626 627 628 629 630 631 632

  The free space map is in shared memory so resizing is difficult.

* Maintain a map of recently-expired rows

  This allows vacuum to reclaim free space without requiring
  a sequential scan
B
Add:  
Bruce Momjian 已提交
633

B
Add:  
Bruce Momjian 已提交
634

635 636
Locking
=======
637 638

* Make locking of shared data structures more fine-grained
639 640 641 642

  This requires that more locks be acquired but this would reduce lock
  contention, improving concurrency.

643
* Add code to detect an SMP machine and handle spinlocks accordingly
B
Bruce Momjian 已提交
644 645
  from distributted.net, http://www1.distributed.net/source, 
  in client/common/cpucheck.cpp
646 647 648 649 650 651 652 653 654 655 656

  On SMP machines, it is possible that locks might be released shortly,
  while on non-SMP machines, the backend should sleep so the process
  holding the lock can complete and release it.

* Improve SMP performance on i386 machines

  i386-based SMP machines can generate excessive context switching
  caused by lock failure in high concurrency situations. This may be
  caused by CPU cache line invalidation inefficiencies.

657 658
* Research use of sched_yield() for spinlock acquisition failure

659

660 661
Startup Time
============
B
Bruce Momjian 已提交
662

B
Bruce Momjian 已提交
663
* Experiment with multi-threaded backend [thread]
664 665 666 667 668 669

  This would prevent the overhead associated with process creation. Most
  operating systems have trivial process creation time compared to
  database startup overhead, but a few operating systems (WIn32,
  Solaris) might benefit from threading.

B
Bruce Momjian 已提交
670
* Add connection pooling [pool]
671 672 673 674

  It is unclear if this should be done inside the backend code or done
  by something external like pgpool. The passing of file descriptors to
  existing backends is one of the difficulties with a backend approach.
675

676

677 678
Write-Ahead Log
===============
679

680 681 682 683 684 685 686 687 688 689 690 691
* Eliminate need to write full pages to WAL before page modification [wal]

  Currently, to protect against partial disk page writes, we write the
  full page images to WAL before they are modified so we can correct any
  partial page writes during recovery.

* Reduce WAL traffic so only modified values are written rather than
  entire rows (?)
* Turn off after-change writes if fsync is disabled

  If fsync is off, there is no purpose in writing full pages to WAL

B
Bruce Momjian 已提交
692
* Add WAL index reliability improvement to non-btree indexes
693 694 695
* Allow the pg_xlog directory location to be specified during initdb
  with a symlink back to the /data location

B
Add:  
Bruce Momjian 已提交
696
* Allow WAL information to recover corrupted pg_controldata
B
Added:  
Bruce Momjian 已提交
697 698
* Find a way to reduce rotational delay when repeatedly writing
  last WAL page
699 700 701 702
  
  Currently fsync of WAL requires the disk platter to perform a full
  rotation to fsync again. One idea is to write the WAL to different
  offsets that might reduce the rotational delay.
703

B
Bruce Momjian 已提交
704

705 706
Optimizer / Executor
====================
707

708 709 710 711 712 713 714 715
* Add missing optimizer selectivities for date, r-tree, etc
* Allow ORDER BY ... LIMIT 1 to select high/low value without sort or
  index using a sequential scan for highest/lowest values

  If only one value is needed, there is no need to sort the entire
  table. Instead a sequential scan could get the matching value.

* Precompile SQL functions to avoid overhead
B
Add:  
Bruce Momjian 已提交
716
* Add utility to compute accurate random_page_cost value
B
Bruce Momjian 已提交
717
* Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
B
Update:  
Bruce Momjian 已提交
718
* Allow sorting, temp files, temp tables to use multiple work directories
719 720

  This allows the I/O load to be spread across multiple disk drives.
B
Add:  
Bruce Momjian 已提交
721
* Have EXPLAIN ANALYZE highlight poor optimizer estimates
722 723 724 725 726
* Use CHECK constraints to influence optimizer decisions

  CHECK constraints contain information about the distribution of values
  within the table. This is also useful for implementing subtables where
  a tables content is distributed across several subtables.
B
Bruce Momjian 已提交
727

B
Add:  
Bruce Momjian 已提交
728

729 730
Miscellaneous
=============
731 732

* Do async I/O for faster random read-ahead of data
733 734 735 736

  Async I/O allows multiple I/O requests to be sent to the disk with
  results coming back asynchronously.
    
737
* Use mmap() rather than SYSV shared memory or to write WAL files (?) [mmap]
738 739 740 741 742

  This would remove the requirement for SYSV SHM but would introduce
  portability issues. Anonymous mmap is required to prevent I/O
  overhead.

B
Add:  
Bruce Momjian 已提交
743
* Add a script to ask system configuration questions and tune postgresql.conf
744
* -Use background process to write dirty shared buffers to disk
B
Add:  
Bruce Momjian 已提交
745 746
* Use a phantom command counter for nested subtransactions to reduce
  tuple overhead
B
Add:  
Bruce Momjian 已提交
747

748

749
Source Code
750 751
===========

B
Bruce Momjian 已提交
752
* Add use of 'const' for variables in source tree
B
Bruce Momjian 已提交
753
* Rename some /contrib modules from pg* to pg_*
B
Bruce Momjian 已提交
754
* Move some things from /contrib into main tree
B
Bruce Momjian 已提交
755
* Remove warnings created by -Wcast-align
B
Bruce Momjian 已提交
756
* Move platform-specific ps status display info from ps_status.c to ports
B
Typo.  
Bruce Momjian 已提交
757
* Improve access-permissions check on data directory in Cygwin (Tom)
B
Bruce Momjian 已提交
758
* Add optional CRC checksum to heap and index pages
B
Bruce Momjian 已提交
759
* -Change representation of whole-tuple parameters to functions
B
Add:  
Bruce Momjian 已提交
760
* Clarify use of 'application' and 'command' tags in SGML docs
B
Bruce Momjian 已提交
761
* Better document ability to build only certain interfaces (Marc)
762
* Remove or relicense modules that are not under the BSD license, if possible
763
* Remove memory/file descriptor freeing before ereport(ERROR)
B
Add:  
Bruce Momjian 已提交
764
* Acquire lock on a relation before building a relcache entry for it
B
Add:  
Bruce Momjian 已提交
765
* Research interaction of setitimer() and sleep() used by statement_timeout
B
Bruce Momjian 已提交
766
* -Add checks for fclose() failure (Tom)
B
Done:  
Bruce Momjian 已提交
767
* -Change CVS ID to PostgreSQL
B
Done:  
Bruce Momjian 已提交
768
* -Exit postmaster if postgresql.conf can not be opened
B
Add:  
Bruce Momjian 已提交
769
* Rename /scripts directory because they are all C programs now
B
Add:  
Bruce Momjian 已提交
770
* Promote debug_query_string into a server-side function current_query()
B
Add:  
Bruce Momjian 已提交
771
* Allow the identifier length to be increased via a configure option
B
Add:  
Bruce Momjian 已提交
772
* Allow binaries to be statically linked so they are more easily relocated
B
Add:  
Bruce Momjian 已提交
773

774

B
Add:  
Bruce Momjian 已提交
775
* Wire Protocol Changes
776
	o Allow dynamic character set handling
B
Add:  
Bruce Momjian 已提交
777
	o Add decoded type, length, precision
778
	o Use compression?
B
Bruce Momjian 已提交
779 780
	o Update clients to use data types, typmod, schema.table.column names of
	  result sets using new query protocol
B
Add:  
Bruce Momjian 已提交
781

782

B
Bruce Momjian 已提交
783 784 785 786 787
---------------------------------------------------------------------------


Developers who have claimed items are:
--------------------------------------
B
Bruce Momjian 已提交
788
* Alvaro is Alvaro Herrera <alvherre@dcc.uchile.cl>
B
Bruce Momjian 已提交
789
* Andrew is Andrew Dunstan <andrew@dunslane.net>
B
Bruce Momjian 已提交
790 791 792
* Bruce is Bruce Momjian <pgman@candle.pha.pa.us> of Software Research Assoc.
* Christopher is Christopher Kings-Lynne <chriskl@familyhealth.com.au> of
    Family Health Network
B
Bruce Momjian 已提交
793
* Claudio is Claudio Natoli <claudio.natoli@memetrics.com>
B
Bruce Momjian 已提交
794
* D'Arcy is D'Arcy J.M. Cain <darcy@druid.net> of The Cain Gang Ltd.
B
Bruce Momjian 已提交
795
* Fabien is Fabien Coelho <coelho@cri.ensmp.fr>
B
Bruce Momjian 已提交
796 797
* Gavin is Gavin Sherry <swm@linuxworld.com.au> of Alcove Systems Engineering
* Greg is Greg Sabino Mullane <greg@turnstep.com>
B
Bruce Momjian 已提交
798
* Hiroshi is Hiroshi Inoue <Inoue@tpf.co.jp>
B
Bruce Momjian 已提交
799
* Jan is Jan Wieck <JanWieck@Yahoo.com> of Afilias, Inc.
B
Bruce Momjian 已提交
800
* Joe is Joe Conway <mail@joeconway.com>
801 802
* Karel is Karel Zak <zakkr@zf.jcu.cz>
* Kris is Kris Jurka 
B
Fix :  
Bruce Momjian 已提交
803
* Magnus is Magnus Hagander <mha@sollentuna.net>
B
Bruce Momjian 已提交
804
* Marc is Marc Fournier <scrappy@hub.org> of PostgreSQL, Inc.
B
Bruce Momjian 已提交
805
* Matthew T. O'Connor <matthew@zeut.net>
B
Bruce Momjian 已提交
806
* Michael is Michael Meskes <meskes@postgresql.org> of Credativ
B
Bruce Momjian 已提交
807
* Neil is Neil Conway <neilc@samurai.com>
B
Bruce Momjian 已提交
808
* Oleg is Oleg Bartunov <oleg@sai.msu.su>
809
* Peter is Peter Eisentraut <peter_e@gmx.net>
B
Bruce Momjian 已提交
810
* Philip is Philip Warner <pjw@rhyme.com.au> of Albatross Consulting Pty. Ltd.
B
Bruce Momjian 已提交
811
* Rod is Rod Taylor <pg@rbt.ca>
812
* Simon is Simon Riggs
B
Bruce Momjian 已提交
813
* Stephan is Stephan Szabo <sszabo@megazone23.bigpanda.com>
B
Bruce Momjian 已提交
814
* Tatsuo is Tatsuo Ishii <t-ishii@sra.co.jp> of Software Research Assoc.
815
* Teodor is 
B
Bruce Momjian 已提交
816
* Tom is Tom Lane <tgl@sss.pgh.pa.us> of Red Hat