TODO 56.8 KB
Newer Older
B
Update:  
Bruce Momjian 已提交
1

B
Bruce Momjian 已提交
2 3
PostgreSQL TODO List
====================
B
Bruce Momjian 已提交
4
Current maintainer:	Bruce Momjian (bruce@momjian.us)
5
Last updated:		Mon Sep 18 10:56:04 EDT 2006
M
Marc G. Fournier 已提交
6

B
Bruce Momjian 已提交
7 8
The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html.
B
Bruce Momjian 已提交
9

B
Bruce Momjian 已提交
10
#A hyphen, "-", marks changes that will appear in the upcoming 8.2 release.#
B
Bruce Momjian 已提交
11
#A percent sign, "%", marks items that are easier to implement.#
B
Bruce Momjian 已提交
12 13 14 15

Bracketed items, "[]", have more detail.

This list contains all known PostgreSQL bugs and feature requests. If
B
Bruce Momjian 已提交
16
you would like to work on an item, please read the Developer's FAQ
B
Bruce Momjian 已提交
17
first.
B
Bruce Momjian 已提交
18

B
Bruce Momjian 已提交
19

20 21
Administration
==============
B
Bruce Momjian 已提交
22

B
Done:  
Bruce Momjian 已提交
23
* -Make postmater and postgres options distinct so the postmaster -o
B
Update:  
Bruce Momjian 已提交
24
  option is no longer needed
B
Bruce Momjian 已提交
25
* -Allow pooled connections to list all prepared statements
26 27

  This would allow an application inheriting a pooled connection to know
28
  the statements prepared in the current session.
29

B
Bruce Momjian 已提交
30 31
* Allow major upgrades without dump/reload, perhaps using pg_upgrade 
  [pg_upgrade]
B
Bruce Momjian 已提交
32
* Check for unreferenced table files created by transactions that were
B
Bruce Momjian 已提交
33
  in-progress when the server terminated abruptly
B
Bruce Momjian 已提交
34 35 36

  http://archives.postgresql.org/pgsql-patches/2006-06/msg00096.php

B
Bruce Momjian 已提交
37 38
* Allow administrators to safely terminate individual sessions either
  via an SQL function or SIGTERM 
39

B
Bruce Momjian 已提交
40 41 42 43
  Lock table corruption following SIGTERM of an individual backend
  has been reported in 8.0.  A possible cause was fixed in 8.1, but
  it is unknown whether other problems exist.  This item mostly
  requires additional testing rather than of writing any new code.
44
  http://archives.postgresql.org/pgsql-hackers/2006-08/msg00174.php
45

B
Bruce Momjian 已提交
46
* %Set proper permissions on non-system schemas during db creation
B
Add:  
Bruce Momjian 已提交
47

B
Bruce Momjian 已提交
48 49
  Currently all schemas are owned by the super-user because they are
  copied from the template1 database.
B
Add:  
Bruce Momjian 已提交
50

B
Bruce Momjian 已提交
51 52 53
* Support table partitioning that allows a single table to be stored
  in subtables that are partitioned based on the primary key or a WHERE
  clause
B
Add:  
Bruce Momjian 已提交
54
* Add function to report the time of the most recent server reload
B
Add:  
Bruce Momjian 已提交
55 56 57
* Allow statistics collector information to be pulled from the collector
  process directly, rather than requiring the collector to write a
  filesystem file twice a second?
B
Add:  
Bruce Momjian 已提交
58 59 60 61
* Allow log_min_messages to be specified on a per-module basis

  This would allow administrators to see more detailed information from
  specific sections of the backend, e.g. checkpoints, autovacuum, etc.
62 63
  Another idea is to allow separate configuration files for each module,
  or allow arbitrary SET commands to be passed to them.
B
Update:  
Bruce Momjian 已提交
64

B
Done:  
Bruce Momjian 已提交
65
* -Re-enable the GUC full_page_writes in 8.2 when reliability issues have
B
Add:  
Bruce Momjian 已提交
66
  been addressed
B
Add:  
Bruce Momjian 已提交
67 68 69 70 71 72 73 74
* Simplify ability to create partitioned tables

  This would allow creation of partitioned tables without requiring
  creation of rules for INSERT/UPDATE/DELETE, and constraints for
  rapid partition selection.  Options could include range and hash
  partition selection.

* Allow auto-selection of partitioned tables for min/max() operations
B
Add:  
Bruce Momjian 已提交
75

B
Bruce Momjian 已提交
76

B
Bruce Momjian 已提交
77
* Improve replication solutions
78

B
Bruce Momjian 已提交
79
	o Load balancing
B
Bruce Momjian 已提交
80

B
Bruce Momjian 已提交
81 82 83
	  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
84

B
Bruce Momjian 已提交
85
	o Allow replication over unreliable or non-persistent links
B
Bruce Momjian 已提交
86 87


B
Bruce Momjian 已提交
88
* Configuration files
89

B
Done:  
Bruce Momjian 已提交
90
	o -Add "include file" functionality in postgresql.conf
B
Bruce Momjian 已提交
91
	o Allow commenting of variables in postgresql.conf to restore them
B
Bruce Momjian 已提交
92
	  to defaults
B
Bruce Momjian 已提交
93

B
Update:  
Bruce Momjian 已提交
94 95
	  Currently, if a variable is commented out, it keeps the
	  previous uncommented value until a server restarted.
B
Bruce Momjian 已提交
96

B
Done:  
Bruce Momjian 已提交
97
	o -Allow per-database permissions to be set via GRANT
B
Bruce Momjian 已提交
98

99 100
	  Allow database connection checks based on GRANT rules in
	  addition to the existing access checks in pg_hba.conf.
B
Bruce Momjian 已提交
101

B
Add:  
Bruce Momjian 已提交
102 103 104 105 106 107 108 109 110
	o Allow pg_hba.conf to specify host names along with IP addresses

	  Host name lookup could occur when the postmaster reads the
	  pg_hba.conf file, or when the backend starts.  Another
	  solution would be to reverse lookup the connection IP and
	  check that hostname against the host names in pg_hba.conf.
	  We could also then check that the host name maps to the IP
	  address.

B
Bruce Momjian 已提交
111
	o %Allow postgresql.conf file values to be changed via an SQL
B
Bruce Momjian 已提交
112
	  API, perhaps using SET GLOBAL
B
Add:  
Bruce Momjian 已提交
113
	o Allow the server to be stopped/restarted via an SQL API
114
	o -Issue a warning if a change-on-restart-only postgresql.conf value
B
Add:  
Bruce Momjian 已提交
115 116
	  is modified  and the server config files are reloaded
	o Mark change-on-restart-only values in postgresql.conf
B
Bruce Momjian 已提交
117

118

B
Bruce Momjian 已提交
119
* Tablespaces
120

B
Bruce Momjian 已提交
121
	o Allow a database in tablespace t1 with tables created in
B
Bruce Momjian 已提交
122 123
	  tablespace t2 to be used as a template for a new database created
	  with default tablespace t2
B
Add:  
Bruce Momjian 已提交
124

B
Bruce Momjian 已提交
125 126 127 128 129 130 131 132
	  All objects in the default database tablespace must have default
	  tablespace specifications. This is because new databases are
	  created by copying directories. If you mix default tablespace
	  tables and tablespace-specified tables in the same directory,
	  creating a new database from such a mixed directory would create a
	  new database with tables that had incorrect explicit tablespaces.
	  To fix this would require modifying pg_class in the newly copied
	  database, which we don't currently do.
133

B
Bruce Momjian 已提交
134
	o Allow reporting of which objects are in which tablespaces
135

B
Bruce Momjian 已提交
136 137 138 139 140
	  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
141

B
Bruce Momjian 已提交
142
	o %Add a GUC variable to control the tablespace for temporary objects
B
Bruce Momjian 已提交
143
	  and sort files
B
Add:  
Bruce Momjian 已提交
144

B
Bruce Momjian 已提交
145 146
	  It could start with a random tablespace from a supplied list and
	  cycle through the list.
B
Add:  
Bruce Momjian 已提交
147

B
Bruce Momjian 已提交
148 149
	o Allow WAL replay of CREATE TABLESPACE to work when the directory
	  structure on the recovery computer is different from the original
B
Add:  
Bruce Momjian 已提交
150

B
Bruce Momjian 已提交
151
	o Allow per-tablespace quotas
152 153


154 155
* Point-In-Time Recovery (PITR)

B
Bruce Momjian 已提交
156
	  o Add command to archive partially filled write-ahead logs? [pitr]
B
Add:  
Bruce Momjian 已提交
157

B
Bruce Momjian 已提交
158 159
	    Currently only full WAL files are archived. This means that the
	    most recent transactions aren't available for recovery in case
B
Bruce Momjian 已提交
160
	    of a disk failure.
B
Bruce Momjian 已提交
161

B
Done:  
Bruce Momjian 已提交
162
	  o -Automatically force archiving of partially-filled WAL files when
B
Bruce Momjian 已提交
163
	    pg_stop_backup() is called or the server is stopped
B
Done:  
Bruce Momjian 已提交
164
	  o -Add reporting of the current WAL file and offset, perhaps as
B
Bruce Momjian 已提交
165
	    part of partial log file archiving
B
Bruce Momjian 已提交
166
	  o %Create dump tool for write-ahead logs for use in determining
B
Bruce Momjian 已提交
167
	    transaction id for point-in-time recovery
168
	  o Allow a warm standby system to also allow read-only statements
B
Bruce Momjian 已提交
169 170 171 172 173
	    [pitr]

	    This is useful for checking PITR recovery.

	  o Allow the PITR process to be debugged and data examined
174

B
Bruce Momjian 已提交
175 176 177 178 179 180 181 182 183

Monitoring
==========

* Allow server log information to be output as INSERT statements

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

B
Bruce Momjian 已提交
184
* %Add ability to monitor the use of temporary sort files
B
Done:  
Bruce Momjian 已提交
185
* -Allow server logs to be remotely read and removed using SQL commands
B
Done:  
Bruce Momjian 已提交
186
* -Allow protocol-level BIND parameter values to be logged
B
Bruce Momjian 已提交
187

B
Bruce Momjian 已提交
188

189 190
Data Types
==========
B
Bruce Momjian 已提交
191

B
Bruce Momjian 已提交
192 193 194 195
* Improve the MONEY data type

  Change the MONEY data type to use DECIMAL internally, with special
  locale-aware output formatting.
B
Bruce Momjian 已提交
196
  http://archives.postgresql.org/pgsql-general/2005-08/msg01432.php
B
Bruce Momjian 已提交
197

198
* Change NUMERIC to enforce the maximum precision
B
Bruce Momjian 已提交
199 200 201 202 203 204 205 206 207 208 209
* Add NUMERIC division operator that doesn't round?

  Currently NUMERIC _rounds_ the result to the specified precision.  
  This means division can return a result that multiplied by the 
  divisor is greater than the dividend, e.g. this returns a value > 10:

    SELECT (10::numeric(2,0) / 6::numeric(2,0))::numeric(2,0) * 6;

  The positive modulus result returned by NUMERICs might be considered
  inaccurate, in one sense.

B
Add:  
Bruce Momjian 已提交
210
* Fix data types where equality comparison isn't intuitive, e.g. box
B
Done:  
Bruce Momjian 已提交
211 212
* -Zero umasked bits in conversion from INET cast to CIDR
* -Prevent INET cast to CIDR from dropping netmask, SELECT '1.1.1.1'::inet::cidr
B
Done:  
Bruce Momjian 已提交
213
* -Allow INET + INT8 to increment the host part of the address or
B
Bruce Momjian 已提交
214
  throw an error on overflow
B
Done:  
Bruce Momjian 已提交
215
* -Add 'tid != tid ' operator for use in corruption recovery
B
Add:  
Bruce Momjian 已提交
216 217
* Allow user-defined types to specify a type modifier at table creation
  time
B
Bruce Momjian 已提交
218
* Allow user-defined types to accept 'typmod' parameters
B
Bruce Momjian 已提交
219

B
Bruce Momjian 已提交
220 221
  http://archives.postgresql.org/pgsql-hackers/2005-08/msg01142.php
  http://archives.postgresql.org/pgsql-hackers/2005-09/msg00012.php
B
Bruce Momjian 已提交
222
  http://archives.postgresql.org/pgsql-hackers/2006-08/msg00149.php
B
Bruce Momjian 已提交
223

B
>  
Bruce Momjian 已提交
224 225 226 227
* Add support for public SYNONYMs

  http://archives.postgresql.org/pgsql-hackers/2006-03/msg00519.php

B
Add:  
Bruce Momjian 已提交
228 229 230 231
* Fix CREATE CAST on DOMAINs

  http://archives.postgresql.org/pgsql-hackers/2006-05/msg00072.php

B
Bruce Momjian 已提交
232
* Add Globally/Universally Unique Identifier (GUID/UUID)
B
Add:  
Bruce Momjian 已提交
233 234 235 236
* Add support for SQL-standard GENERATED/IDENTITY columns

  http://archives.postgresql.org/pgsql-hackers/2006-07/msg00543.php

B
Add:  
Bruce Momjian 已提交
237 238 239
* Support a data type with specific enumerated values (ENUM)

  http://archives.postgresql.org/pgsql-hackers/2006-08/msg00979.php
B
Add:  
Bruce Momjian 已提交
240

B
Bruce Momjian 已提交
241 242 243 244
* Improve XML support

  http://developer.postgresql.org/index.php/XML_Support

245 246
* Dates and Times

B
Bruce Momjian 已提交
247
	o Allow infinite dates and intervals just like infinite timestamps
248 249
	o Merge hardwired timezone names with the TZ database; allow either 
	  kind everywhere a TZ name is currently taken
B
Done:  
Bruce Momjian 已提交
250
	o -Allow customization of the known set of TZ names (generalize the
251 252 253 254 255
	  present australian_timezones hack)
	o Allow TIMESTAMP WITH TIME ZONE to store the original timezone
	  information, either zone name or offset from UTC [timezone]

	  If the TIMESTAMP value is stored with a time zone name, interval 
B
Update.  
Bruce Momjian 已提交
256
	  computations should adjust based on the time zone rules.
257

B
Done:  
Bruce Momjian 已提交
258
	o -Allow timezone names in SQL strings, '2006-05-24 21:11
B
Add:  
Bruce Momjian 已提交
259
	   Americas/New_York'::timestamptz
B
Add:  
Bruce Momjian 已提交
260
	o Fix SELECT '0.01 years'::interval, '0.01 months'::interval
B
Bruce Momjian 已提交
261 262 263 264 265 266 267 268 269 270 271 272 273
	o Add a GUC variable to allow output of interval values in ISO8601 
	  format
	o Improve timestamptz subtraction to be DST-aware

	  Currently, subtracting one date from another that crosses a
	  daylight savings time adjustment can return '1 day 1 hour', but
	  adding that back to the first date returns a time one hour in
	  the future.  This is caused by the adjustment of '25 hours' to
	  '1 day 1 hour', and '1 day' is the same time the next day, even
	  if daylight savings adjustments are involved.

	o Fix interval display to support values exceeding 2^31 hours
	o Add overflow checking to timestamp and interval arithmetic	
274
	o Add ISO INTERVAL handling
275 276

		  http://archives.postgresql.org/pgsql-hackers/2006-01/msg00250.php
B
Bruce Momjian 已提交
277
		  http://archives.postgresql.org/pgsql-bugs/2006-04/msg00248.php
278

B
Done:  
Bruce Momjian 已提交
279
		o -Add support for day-time syntax, INTERVAL '1 2:03:04' DAY TO 
280
		  SECOND
281 282 283
		o Support ISO INTERVAL syntax if units cannot be determined from
		  the string, and are supplied after the string

B
Bruce Momjian 已提交
284 285 286 287 288
		  The SQL standard states that the units after the string
		  specify the units of the string, e.g. INTERVAL '2' MINUTE
		  should return '00:02:00'. The current behavior has the units
		  restrict the interval value to the specified unit or unit
		  range, INTERVAL '70' SECOND returns '00:00:10'.
289 290 291

		  For syntax that isn't uniquely ISO or PG syntax, like '1' or
		  '1:30', treat as ISO if there is a range specification clause,
B
Bruce Momjian 已提交
292 293 294 295 296 297 298 299 300 301
		  and as PG if there no clause is present, e.g. interpret '1:30'
		  MINUTE TO SECOND as '1 minute 30 seconds', and interpret
		  '1:30' as '1 hour, 30 minutes'.

		  This makes common cases like SELECT INTERVAL '1' MONTH
		  SQL-standard results. The SQL standard supports a limited
		  number of unit combinations and doesn't support unit names in
		  the string. The PostgreSQL syntax is more flexible in the
		  range of units supported, e.g. PostgreSQL supports '1 year 1
		  hour', while the SQL standard does not.
302

303 304 305 306 307 308 309 310 311
		o Add support for year-month syntax, INTERVAL '50-6' YEAR TO MONTH
		o Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS
		  INTERVAL MONTH), and this should return '12 months'
		o Round or truncate values to the requested precision, e.g.
		  INTERVAL '11 months' AS YEAR should return one or zero
		o Support precision, CREATE TABLE foo (a INTERVAL MONTH(3))


* Arrays
B
Bruce Momjian 已提交
312

B
Done:  
Bruce Momjian 已提交
313
	o -Allow NULLs in arrays
B
Bruce Momjian 已提交
314 315
	o Delay resolution of array expression's data type so assignment
	  coercion can be performed on empty array expressions
B
Add:  
Bruce Momjian 已提交
316 317
	o Add support for arrays of domains
	o Add support for arrays of complex types
B
Bruce Momjian 已提交
318

B
Bruce Momjian 已提交
319

320 321
* Binary Data

B
Bruce Momjian 已提交
322
	o Improve vacuum of large objects, like /contrib/vacuumlo?
B
Bruce Momjian 已提交
323
	o Add security checking for large objects
B
Bruce Momjian 已提交
324
	o Auto-delete large objects when referencing row is deleted
325

B
Bruce Momjian 已提交
326
          /contrib/lo offers this functionality.
327 328 329

	o Allow read/write into TOAST values like large objects

B
 
Bruce Momjian 已提交
330
	  This requires the TOAST column to be stored EXTERNAL.
331

B
Add:  
Bruce Momjian 已提交
332 333 334 335
	o Add API for 64-bit large object access

	  http://archives.postgresql.org/pgsql-hackers/2005-09/msg00781.php

336

B
Bruce Momjian 已提交
337 338 339 340
Functions
=========

* Allow INET subnet tests using non-constants to be indexed
B
Done:  
Bruce Momjian 已提交
341
* -Add transaction_timestamp(), statement_timestamp(), clock_timestamp()
B
Bruce Momjian 已提交
342 343 344 345 346 347 348
  functionality

  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.

B
Bruce Momjian 已提交
349
* %Add pg_get_acldef(), pg_get_typedefault(), pg_get_attrdef(),
B
Bruce Momjian 已提交
350
  pg_get_tabledef(), pg_get_domaindef(), pg_get_functiondef()
B
Bruce Momjian 已提交
351 352 353

  These would be for application use, not for use by pg_dump.

B
Done:  
Bruce Momjian 已提交
354
* -Allow to_char() to print localized month names
B
Add:  
Bruce Momjian 已提交
355
* Allow to_date() and to_timestamp() accept localized month names
B
Add:  
Bruce Momjian 已提交
356 357 358 359
* Add missing parameter handling in to_char()

	http://archives.postgresql.org/pgsql-hackers/2005-12/msg00948.php

B
Bruce Momjian 已提交
360 361 362 363 364 365 366 367 368 369 370 371 372 373 374
* Allow functions to have a schema search path specified at creation time
* Allow substring/replace() to get/set bit values
* Allow to_char() on interval values to accumulate the highest unit
  requested

  Some special format flag would be required to request such
  accumulation.  Such functionality could also be added to EXTRACT. 
  Prevent accumulation that crosses the month/day boundary because of
  the uneven number of days in a month.

	o to_char(INTERVAL '1 hour 5 minutes', 'MI') => 65
	o to_char(INTERVAL '43 hours 20 minutes', 'MI' ) => 2600 
	o to_char(INTERVAL '43 hours 20 minutes', 'WK:DD:HR:MI') => 0:1:19:20
	o to_char(INTERVAL '3 years 5 months','MM') => 41

B
Done:  
Bruce Momjian 已提交
375
* -Add sleep() function, remove from regress.c
B
Bruce Momjian 已提交
376
* -Allow user-defined functions retuning a domain value to enforce domain
B
Add:  
Bruce Momjian 已提交
377
  constraints
B
Add:  
Bruce Momjian 已提交
378
* Add SPI_gettypmod() to return the typemod for a TupleDesc
B
Add:  
Bruce Momjian 已提交
379
* Allow inlining of set-returning functions
B
Bruce Momjian 已提交
380

B
Bruce Momjian 已提交
381

382 383
Multi-Language Support
======================
B
Bruce Momjian 已提交
384

385
* Add NCHAR (as distinguished from ordinary varchar),
B
Update:  
Bruce Momjian 已提交
386
* Allow locale to be set at database creation
387

B
Bruce Momjian 已提交
388 389 390 391
  Currently locale can only be set during initdb.  No global tables have
  locale-aware columns.  However, the database template used during
  database creation might have locale-aware indexes.  The indexes would
  need to be reindexed to match the new locale.
392

B
Bruce Momjian 已提交
393
* Allow encoding on a per-column basis optionally using the ICU library:
394

B
Bruce Momjian 已提交
395
  Right now only one encoding is allowed per database.  [locale]
396
  http://archives.postgresql.org/pgsql-hackers/2005-03/msg00932.php
B
Bruce Momjian 已提交
397 398
  http://archives.postgresql.org/pgsql-patches/2005-08/msg00309.php
  http://archives.postgresql.org/pgsql-patches/2006-03/msg00233.php
B
Bruce Momjian 已提交
399
  http://archives.postgresql.org/pgsql-hackers/2006-09/msg00662.php
400

B
Bruce Momjian 已提交
401
* Add CREATE COLLATE?  [locale]
B
Bruce Momjian 已提交
402
* Support multiple simultaneous character sets, per SQL92
B
Bruce Momjian 已提交
403
* Improve UTF8 combined character handling?
404 405
* Add octet_length_server() and octet_length_client()
* Make octet_length_client() the same as octet_length()?
B
Add:  
Bruce Momjian 已提交
406
* Fix problems with wrong runtime encoding conversion for NLS message files
B
Bruce Momjian 已提交
407 408 409
* Add URL to more complete multi-byte regression tests

  http://archives.postgresql.org/pgsql-hackers/2005-07/msg00272.php
B
Add:  
Bruce Momjian 已提交
410

B
Bruce Momjian 已提交
411 412 413 414
* Fix ILIKE and regular expressions to handle case insensitivity
  properly in multibyte encodings

  http://archives.postgresql.org/pgsql-bugs/2005-10/msg00001.php
B
Bruce Momjian 已提交
415
  http://archives.postgresql.org/pgsql-patches/2005-11/msg00173.php
B
Bruce Momjian 已提交
416

417

418 419
Views / Rules
=============
B
Bruce Momjian 已提交
420

N
Neil Conway 已提交
421
* Automatically create rules on views so they are updateable, per SQL99
B
Bruce Momjian 已提交
422 423

  We can only auto-create rules for simple views.  For more complex
N
Neil Conway 已提交
424
  cases users will still have to write rules manually.
B
Bruce Momjian 已提交
425
  http://archives.postgresql.org/pgsql-hackers/2006-03/msg00586.php
B
Bruce Momjian 已提交
426

B
Bruce Momjian 已提交
427
* Add the functionality for WITH CHECK OPTION clause of CREATE VIEW
B
Bruce Momjian 已提交
428
* Allow NOTIFY in rules involving conditionals
B
Bruce Momjian 已提交
429
* Allow VIEW/RULE recompilation when the underlying tables change
430

B
Update:  
Bruce Momjian 已提交
431 432 433 434
  Another issue is whether underlying table changes should be reflected
  in the view, e.g. should SELECT * show additional columns if they
  are added after the view is created.

B
Add:  
Bruce Momjian 已提交
435

436 437
SQL Commands
============
B
Bruce Momjian 已提交
438

B
Add:  
Bruce Momjian 已提交
439
* Add CORRESPONDING BY to UNION/INTERSECT/EXCEPT
B
Add:  
Bruce Momjian 已提交
440
* Add ROLLUP, CUBE, GROUPING SETS options to GROUP BY
B
Bruce Momjian 已提交
441
* %Allow SET CONSTRAINTS to be qualified by schema/table name
B
Done:  
Bruce Momjian 已提交
442
* -Allow TRUNCATE ... CASCADE/RESTRICT
B
Bruce Momjian 已提交
443 444 445

  This is like DELETE CASCADE, but truncates.

B
Bruce Momjian 已提交
446
* %Add a separate TRUNCATE permission
B
Add:  
Bruce Momjian 已提交
447 448 449 450

  Currently only the owner can TRUNCATE a table because triggers are not
  called, and the table is locked in exclusive mode.

B
Add:  
Bruce Momjian 已提交
451
* Allow PREPARE of cursors
B
Add:  
Bruce Momjian 已提交
452 453 454 455 456 457 458 459
* Allow finer control over the caching of prepared query plans

  Currently, queries prepared via the libpq API are planned on first
  execute using the supplied parameters --- allow SQL PREPARE to do the
  same.  Also, allow control over replanning prepared queries either
  manually or automatically when statistics for execute parameters
  differ dramatically from those used during planning.

B
Add:  
Bruce Momjian 已提交
460 461
* Invalidate prepared queries, like INSERT, when the table definition
  is altered
462 463 464 465 466
* 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
Bruce Momjian 已提交
467
* Add optional textual message to NOTIFY
468 469 470 471 472

  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
473
* Add a GUC variable to warn about non-standard SQL usage in queries
474
* Add SQL-standard MERGE command, typically used to merge two tables
B
Bruce Momjian 已提交
475
  [merge]
476 477 478 479 480 481

  This is similar to UPDATE, then for unmatched rows, INSERT.
  Whether concurrent access allows modifications which could cause
  row loss is implementation independent.

* Add REPLACE or UPSERT command that does UPDATE, or on failure, INSERT
B
Bruce Momjian 已提交
482
  [merge]
B
Bruce Momjian 已提交
483 484

  To implement this cleanly requires that the table have a unique index
485 486 487
  so duplicate checking can be easily performed.  It is possible to
  do it without a unique index if we require the user to LOCK the table
  before the MERGE.
B
Bruce Momjian 已提交
488

B
Bruce Momjian 已提交
489 490
* Add NOVICE output level for helpful messages like automatic sequence/index
  creation
B
Done:  
Bruce Momjian 已提交
491
* -Add COMMENT ON for all cluster global objects (roles, databases
B
Bruce Momjian 已提交
492
  and tablespaces)
B
Done:  
Bruce Momjian 已提交
493
* -Make row-wise comparisons work per SQL spec
B
Add:  
Bruce Momjian 已提交
494 495 496 497 498

  Right now, '(a, b) < (1, 2)' is processed as 'a < 1 and b < 2', but
  the SQL standard requires it to be processed as a column-by-column
  comparison, so the proper comparison is '(a < 1) OR (a = 1 AND b < 2)'.

499
* Add RESET CONNECTION command to reset all session state
B
Add:  
Bruce Momjian 已提交
500

B
Add:  
Bruce Momjian 已提交
501
  This would include resetting of all variables (RESET ALL), dropping of
502 503 504 505
  temporary tables, removing any NOTIFYs, cursors, open transactions,
  prepared queries, currval()s, etc.  This could be used  for connection
  pooling.  We could also change RESET ALL to have this functionality.  
  The difficult of this features is allowing RESET ALL to not affect 
B
Bruce Momjian 已提交
506 507
  changes made by the interface driver for its internal use.  One idea 
  is for this to be a protocol-only feature.  Another approach is to 
508
  notify the protocol when a RESET CONNECTION command is used.
B
Bruce Momjian 已提交
509
  http://archives.postgresql.org/pgsql-patches/2006-04/msg00192.php
B
Add:  
Bruce Momjian 已提交
510

511
* Add GUC to issue notice about statements that use unjoined tables
B
Bruce Momjian 已提交
512
* Allow EXPLAIN to identify tables that were skipped because of 
513
  constraint_exclusion
B
Bruce Momjian 已提交
514
* Allow EXPLAIN output to be more easily processed by scripts
B
Add:  
Bruce Momjian 已提交
515 516 517 518 519 520 521 522 523
* -Enable escape_string_warning and standard_conforming_strings
* Make standard_conforming_strings the default in 8.3?

  When this is done, backslash-quote should be prohibited in non-E''
  strings because of possible confusion over how such strings treat
  backslashes.  Basically, '' is always safe for a literal single
  quote, while \' might or might not be based on the backslash
  handling rules.

B
Add:  
Bruce Momjian 已提交
524
* Simplify dropping roles that have objects in several databases
B
Add:  
Bruce Momjian 已提交
525
* Allow COMMENT ON to accept an expression rather than just a string
B
Add:  
Bruce Momjian 已提交
526 527
* Allow the count returned by SELECT, etc to be to represent as an int64
  to allow a higher range of values
B
Add:  
Bruce Momjian 已提交
528
* Make CLUSTER preserve recently-dead tuples per MVCC requirements
B
Bruce Momjian 已提交
529
* Add SQL99 WITH clause to SELECT
B
Update:  
Bruce Momjian 已提交
530
* Add SQL:2003 WITH RECURSIVE (hierarchical) queries to SELECT
B
Bruce Momjian 已提交
531 532 533 534
* Add DEFAULT .. AS OWNER so permission checks are done as the table
  owner

  This would be useful for SERIAL nextval() calls and CHECK constraints.
B
Bruce Momjian 已提交
535

B
Add:  
Bruce Momjian 已提交
536 537
* Add a GUC to control whether BEGIN inside a transcation should abort
  the transaction.
B
Bruce Momjian 已提交
538
* Allow DISTINCT to work in multiple-argument aggregate calls
B
Bruce Momjian 已提交
539 540
* Add column to pg_stat_activity that shows the progress of long-running
  commands like CREATE INDEX and VACUUM
B
Add:  
Bruce Momjian 已提交
541
* Implement SQL:2003 window functions
B
Bruce Momjian 已提交
542

B
Bruce Momjian 已提交
543

544 545 546 547 548 549
* CREATE

	o Allow CREATE TABLE AS to determine column lengths for complex
	  expressions like SELECT col1 || col2
	o Use more reliable method for CREATE DATABASE to get a consistent
	  copy of db?
N
Neil Conway 已提交
550
	o -Add ON COMMIT capability to CREATE TABLE AS ... SELECT
551 552 553


* UPDATE
B
Done:  
Bruce Momjian 已提交
554 555
	o -Allow an alias to be provided for the target table in
	  UPDATE/DELETE (Neil)
B
Update:  
Bruce Momjian 已提交
556 557 558
	o -Allow UPDATE tab SET ROW (col, ...) = (val, ...) for updating
	  multiple columns
	o Allow UPDATE tab SET ROW (col, ...) = (SELECT...)
559

560
	  http://archives.postgresql.org/pgsql-hackers/2006-07/msg01306.php
561

562

B
Bruce Momjian 已提交
563
* ALTER
564

B
Bruce Momjian 已提交
565
	o %Have ALTER TABLE RENAME rename SERIAL sequence names
B
Bruce Momjian 已提交
566
	o Add ALTER DOMAIN to modify the underlying data type
B
Bruce Momjian 已提交
567
	o %Allow ALTER TABLE ... ALTER CONSTRAINT ... RENAME
568

569
	  http://archives.postgresql.org/pgsql-patches/2006-02/msg00168.php
570

B
Bruce Momjian 已提交
571
	o %Allow ALTER TABLE to change constraint deferrability and actions
B
Bruce Momjian 已提交
572
	o Add missing object types for ALTER ... SET SCHEMA
573
	o Allow ALTER TABLESPACE to move to different directories
574
	o Allow databases to be moved to different tablespaces
575 576
	o Allow moving system tables to other tablespaces, where possible

B
 
Bruce Momjian 已提交
577
	  Currently non-global system tables must be in the default database
578
	  tablespace. Global system tables can never be moved.
579

B
Add:  
Bruce Momjian 已提交
580
	o Prevent parent tables from altering or dropping constraints
581 582 583 584
	  like CHECK that are inherited by child tables unless CASCADE
	  is used
	o %Prevent child tables from altering or dropping constraints
          like CHECK that were inherited from the parent table
B
Done:  
Bruce Momjian 已提交
585
	o -Add ALTER TABLE tab INHERIT / NO INHERIT  parent
B
Add:  
Bruce Momjian 已提交
586
	o Have ALTER INDEX update the name of a constraint using that index
B
Update:  
Bruce Momjian 已提交
587
	o Add ALTER TABLE RENAME CONSTRAINT, update index name also
B
Bruce Momjian 已提交
588

B
Bruce Momjian 已提交
589

B
Bruce Momjian 已提交
590
* CLUSTER
591

B
Bruce Momjian 已提交
592
	o Automatically maintain clustering on a table
593

B
 
Bruce Momjian 已提交
594 595
	  This might require some background daemon to maintain clustering
	  during periods of low usage. It might also require tables to be only
N
Neil Conway 已提交
596
	  partially filled for easier reorganization.  Another idea would
B
 
Bruce Momjian 已提交
597
          be to create a merged heap/index data file so an index lookup would
B
Bruce Momjian 已提交
598
	  automatically access the heap data too.  A third idea would be to
B
Bruce Momjian 已提交
599 600
	  store heap rows in hashed groups, perhaps using a user-supplied
	  hash function.
B
Bruce Momjian 已提交
601
	  http://archives.postgresql.org/pgsql-performance/2004-08/msg00349.php
602

B
Bruce Momjian 已提交
603
	o %Add default clustering to system tables
B
Bruce Momjian 已提交
604

B
 
Bruce Momjian 已提交
605 606
	  To do this, determine the ideal cluster index for each system
	  table and set the cluster setting during initdb.
607

B
Bruce Momjian 已提交
608

B
Bruce Momjian 已提交
609
* COPY
610

611
	o Allow COPY to report error lines and continue
612

B
 
Bruce Momjian 已提交
613 614
	  This requires the use of a savepoint before each COPY line is
	  processed, with ROLLBACK on COPY failure.
615

B
Done:  
Bruce Momjian 已提交
616
	o -Have COPY return the number of rows loaded/unloaded?
B
Update:  
Bruce Momjian 已提交
617
	o Allow COPY on a newly-created table to skip WAL logging
B
Add:  
Bruce Momjian 已提交
618

B
Update:  
Bruce Momjian 已提交
619
	  On crash recovery, the table involved in the COPY would
B
Bruce Momjian 已提交
620
	  be removed or have its heap and index files truncated.  One
B
Update.  
Bruce Momjian 已提交
621 622 623
	  issue is that no other backend should be able to add to 
	  the table at the same time, which is something that is 
	  currently allowed.
B
Bruce Momjian 已提交
624

B
Done:  
Bruce Momjian 已提交
625
	o -Allow COPY (SELECT ...) TO 'filename'
B
Add:  
Bruce Momjian 已提交
626

B
Add:  
Bruce Momjian 已提交
627

B
Bruce Momjian 已提交
628
* GRANT/REVOKE
629

B
Bruce Momjian 已提交
630
	o Allow column-level privileges
B
Bruce Momjian 已提交
631
	o %Allow GRANT/REVOKE permissions to be applied to all schema objects
B
Done:  
Bruce Momjian 已提交
632
	  with one command
B
Bruce Momjian 已提交
633 634 635 636 637

	  The proposed syntax is:
		GRANT SELECT ON ALL TABLES IN public TO phpuser;
		GRANT SELECT ON NEW TABLES IN public TO phpuser;

B
Bruce Momjian 已提交
638
	o Allow GRANT/REVOKE permissions to be inherited by objects based on
B
Bruce Momjian 已提交
639 640
	  schema permissions

B
Bruce Momjian 已提交
641
	o Allow SERIAL sequences to inherit permissions from the base table?
B
Add:  
Bruce Momjian 已提交
642

B
Bruce Momjian 已提交
643

B
Bruce Momjian 已提交
644
* CURSOR
645

646
	o Allow UPDATE/DELETE WHERE CURRENT OF cursor
647

B
 
Bruce Momjian 已提交
648 649 650 651
	  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.
652 653

	o Prevent DROP TABLE from dropping a row referenced by its own open
B
Bruce Momjian 已提交
654
	  cursor?
655

B
Done:  
Bruce Momjian 已提交
656
	o -Allow pooled connections to list all open WITH HOLD cursors
657

B
 
Bruce Momjian 已提交
658 659
	  Because WITH HOLD cursors exist outside transactions, this allows
	  them to be listed so they can be closed.
B
Bruce Momjian 已提交
660

B
Bruce Momjian 已提交
661

B
Bruce Momjian 已提交
662
* INSERT
663

664
	o Allow INSERT/UPDATE of the system-generated oid value for a row
B
Done:  
Bruce Momjian 已提交
665
	o -Allow INSERT INTO tab (col1, ..) VALUES (val1, ..), (val2, ..)
B
Done:  
Bruce Momjian 已提交
666
	o -Allow INSERT/UPDATE ... RETURNING new.col or old.col
B
Add:  
Bruce Momjian 已提交
667 668
	o In rules, allow VALUES() to contain a mixture of 'old' and 'new'
	  references
B
Bruce Momjian 已提交
669

B
Bruce Momjian 已提交
670

B
Bruce Momjian 已提交
671
* SHOW/SET
672

B
Bruce Momjian 已提交
673
	o Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM
B
Bruce Momjian 已提交
674
	  ANALYZE, and CLUSTER
B
Bruce Momjian 已提交
675
	o Add SET PATH for schemas?
676

B
 
Bruce Momjian 已提交
677
	  This is basically the same as SET search_path.
B
Bruce Momjian 已提交
678

B
Bruce Momjian 已提交
679

B
Bruce Momjian 已提交
680 681 682 683 684 685
* Referential Integrity

	o Add MATCH PARTIAL referential integrity
	o Change foreign key constraint for array -> element to mean element
	  in array?
	o Enforce referential integrity for system tables
B
Add:  
Bruce Momjian 已提交
686 687 688 689 690
	o Fix problem when cascading referential triggers make changes on
	  cascaded tables, seeing the tables in an intermediate state

	  http://archives.postgresql.org/pgsql-hackers/2005-09/msg00174.php
	  http://archives.postgresql.org/pgsql-hackers/2005-09/msg00174.php
B
Bruce Momjian 已提交
691

692 693 694 695 696 697
	o Allow DEFERRABLE and end-of-statement UNIQUE constraints?

	  This would allow UPDATE tab SET col = col + 1 to work if col has
	  a unique index.  Currently, uniqueness checks are done while the
	  command is being executed, rather than at the end of the statement
	  or transaction.
B
Bruce Momjian 已提交
698
	  http://people.planetpostgresql.org/greg/index.php?/archives/2006/06/10.html
699
	  http://archives.postgresql.org/pgsql-hackers/2006-09/msg01458.php
700

B
Bruce Momjian 已提交
701

702 703
* Server-Side Languages

704 705 706
	o PL/pgSQL
		o Fix RENAME to work on variables other than OLD/NEW
		o Allow function parameters to be passed by name,
B
Fix:  
Bruce Momjian 已提交
707
		  get_employee_salary(12345 AS emp_id, 2001 AS tax_year)
B
Bruce Momjian 已提交
708
		o Add Oracle-style packages  (Pavel)
B
Bruce Momjian 已提交
709

B
Bruce Momjian 已提交
710
		  A package would be a schema with session-local variables,
B
Bruce Momjian 已提交
711
		  public/private functions, and initialization functions.  It
B
Bruce Momjian 已提交
712 713 714
		  is also possible to implement these capabilities
		  in all schemas and not use a separate "packages"
		  syntax at all.
B
Bruce Momjian 已提交
715
		  http://archives.postgresql.org/pgsql-hackers/2006-08/msg00384.php
B
Bruce Momjian 已提交
716

717 718 719 720 721 722 723 724 725 726 727
		o Allow handling of %TYPE arrays, e.g. tab.col%TYPE[]
		o Allow listing of record column names, and access to
		  record columns via variables, e.g. columns := r.(*),
		  tval2 := r.(colname)

		  http://archives.postgresql.org/pgsql-patches/2005-07/msg00458.php
		  http://archives.postgresql.org/pgsql-patches/2006-05/msg00302.php
		  http://archives.postgresql.org/pgsql-patches/2006-06/msg00031.php

		o Add MOVE
		o Add single-step debugging of functions
B
Update:  
Bruce Momjian 已提交
728 729 730 731 732
		o Add support for WITH HOLD and SCROLL cursors

		  PL/pgSQL cursors should support the same syntax as
		  backend cursors.

733 734 735 736
		o Allow PL/RETURN to return row or record functions

		  http://archives.postgresql.org/pgsql-patches/2005-11/msg00045.php

B
Add:  
Bruce Momjian 已提交
737 738 739 740
		o Fix memory leak from exceptions

		  http://archives.postgresql.org/pgsql-performance/2006-06/msg00305.php

B
Add:  
Bruce Momjian 已提交
741 742 743 744
		o Fix problems with RETURN NEXT on tables with
		  dropped/added columns after function creation

		  http://archives.postgresql.org/pgsql-patches/2006-02/msg00165.php
745 746 747 748 749 750 751 752

	o Other
		o Add table function support to pltcl, plpython
		o Add support for polymorphic arguments and return types to
		  languages other than PL/PgSQL
		o Add capability to create and call PROCEDURES
		o Add support for OUT and INOUT parameters to languages other 
		  than PL/PgSQL
B
Bruce Momjian 已提交
753 754 755
		o Add PL/Python tracebacks

		  http://archives.postgresql.org/pgsql-patches/2006-02/msg00288.php
B
Bruce Momjian 已提交
756

B
Bruce Momjian 已提交
757
		o -Allow PL/python to return composite types and result sets
B
Add:  
Bruce Momjian 已提交
758

B
Add:  
Bruce Momjian 已提交
759

760 761
Clients
=======
B
Bruce Momjian 已提交
762

763
* -Have initdb set the input DateStyle (MDY or DMY) based on locale
764 765 766
* Have pg_ctl look at PGHOST in case it is a socket directory?
* Allow pg_ctl to work properly with configuration files located outside
  the PGDATA directory
767

768 769 770 771
  pg_ctl can not read the pid file because it isn't located in the
  config directory but in the PGDATA directory.  The solution is to
  allow pg_ctl to read and understand postgresql.conf to find the
  data_directory value.
772

773 774

* psql
B
Bruce Momjian 已提交
775

776 777 778 779 780 781 782
	o Have psql show current values for a sequence
	o Move psql backslash database information into the backend, use
	  mnemonic commands? [psql]

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

B
Update:  
Bruce Momjian 已提交
783
	o Fix psql's \d commands more consistent
B
Update:  
Bruce Momjian 已提交
784 785

	  http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php
B
Update:  
Bruce Momjian 已提交
786
	  http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php
B
Update:  
Bruce Momjian 已提交
787

788 789 790
	o Allow psql \pset boolean variables to set to fixed values, rather
	  than toggle
	o Consistently display privilege information for all objects in psql
B
Done:  
Bruce Momjian 已提交
791
	o -Improve psql's handling of multi-line statements
B
Bruce Momjian 已提交
792

793 794
	  Currently, while \e saves a single statement as one entry, interactive
	  statements are saved one line at a time.  Ideally all statements
N
Neil Conway 已提交
795
	  would be saved like \e does.
B
Bruce Momjian 已提交
796

B
Done:  
Bruce Momjian 已提交
797
	o -Allow multi-line column values to align in the proper columns
B
Bruce Momjian 已提交
798 799 800 801 802

	  If the second output column value is 'a\nb', the 'b' should appear
	  in the second display column, rather than the first column as it
	  does now.

B
Done:  
Bruce Momjian 已提交
803
	o -Display IN, INOUT, and OUT parameters in \df
B
Add:  
Bruce Momjian 已提交
804 805 806 807 808
	o Add auto-expanded mode so expanded output is used if the row
	  length is wider than the screen width.  

	  Consider using auto-expanded mode for backslash commands like \df+.

B
Add:  
Bruce Momjian 已提交
809 810 811 812 813 814 815 816 817
	o Prevent tab completion of SET TRANSACTION from querying the
	  database and therefore preventing the transaction isolation
	  level from being set.

	  Currently, SET <tab> causes a database lookup to check all
	  supported session variables.  This query causes problems
	  because setting the transaction isolation level must be the
	  first statement of a transaction.

B
Bruce Momjian 已提交
818

B
Bruce Momjian 已提交
819
* pg_dump
820

B
Done:  
Bruce Momjian 已提交
821 822
	o -Allow pg_dump to use multiple -t and -n switches, exclusion
	   ability, and regular expression object matching
B
Bruce Momjian 已提交
823
	o %Add dumping of comments on index columns and composite type columns
B
Bruce Momjian 已提交
824
	o %Add full object name to the tag field.  eg. for operators we need
B
Bruce Momjian 已提交
825
	  '=(integer, integer)', instead of just '='.
B
Bruce Momjian 已提交
826
	o Add pg_dumpall custom format dumps?
B
Done:  
Bruce Momjian 已提交
827
	o -Update pg_dump and psql to use the new COPY libpq API (Christopher)
B
Bruce Momjian 已提交
828 829
	o Remove unnecessary function pointer abstractions in pg_dump source
	  code
B
Add:  
Bruce Momjian 已提交
830 831 832 833
	o Allow selection of individual object(s) of all types, not just
	  tables
	o In a selective dump, allow dumping of an object and all its 
	  dependencies
B
Add:  
Bruce Momjian 已提交
834
	o Add options like pg_restore -l and -L to pg_dump
B
Bruce Momjian 已提交
835
	o Stop dumping CASCADE on DROP TYPE commands in clean mode
B
Add:  
Bruce Momjian 已提交
836 837
	o Allow pg_dump --clean to drop roles that own objects or have
	  privileges
B
Bruce Momjian 已提交
838
	o Add -f to pg_dumpall
B
Done:  
Bruce Momjian 已提交
839

B
Bruce Momjian 已提交
840

841 842
* ecpg

M
Michael Meskes 已提交
843
	o Docs
844

B
 
Bruce Momjian 已提交
845 846
	  Document differences between ecpg and the SQL standard and
	  information about the Informix-compatibility module.
847

B
Bruce Momjian 已提交
848
	o Solve cardinality > 1 for input descriptors / variables?
B
Bruce Momjian 已提交
849
	o Add a semantic check level, e.g. check if a table really exists
B
Bruce Momjian 已提交
850
	o fix handling of DB attributes that are arrays
B
Bruce Momjian 已提交
851
	o Use backend PREPARE/EXECUTE facility for ecpg where possible
B
Update:  
Bruce Momjian 已提交
852
	o Implement SQLDA
M
Michael Meskes 已提交
853
	o Fix nested C comments
B
Bruce Momjian 已提交
854
	o %sqlwarn[6] should be 'W' if the PRECISION or SCALE value specified
855
	o Make SET CONNECTION thread-aware, non-standard?
856
	o Allow multidimensional arrays
B
Bruce Momjian 已提交
857
	o Add internationalized message strings
B
Update:  
Bruce Momjian 已提交
858
	o Implement COPY FROM STDIN
B
Bruce Momjian 已提交
859

B
Bruce Momjian 已提交
860

B
Bruce Momjian 已提交
861
* libpq
862

B
Done:  
Bruce Momjian 已提交
863
	o -Add a function to support Parse/DescribeStatement capability
B
Modify:  
Bruce Momjian 已提交
864
	o Add PQescapeIdentifierConn()
865 866 867 868 869
	o Prevent PQfnumber() from lowercasing unquoted the column name

	  PQfnumber() should never have been doing lowercasing, but 
	  historically it has so we need a way to prevent it

870
	o Allow statement results to be automatically batched to the client
871

N
Neil Conway 已提交
872
	  Currently, all statement results are transferred to the libpq
873 874
	  client before libpq makes the results available to the 
	  application.  This feature would allow the application to make
N
Neil Conway 已提交
875
	  use of the first result rows while the rest are transferred, or
876
	  held on the server waiting for them to be requested by libpq.
877
	  One complexity is that a statement like SELECT 1/col could error
878 879 880
	  out mid-way through the result set.


B
Bruce Momjian 已提交
881 882
Triggers
========
883 884 885 886 887 888
* 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.

889
* Allow triggers to be disabled in only the current session.
890

891 892 893
  This is currently possible by starting a multi-statement transaction,
  modifying the system tables, performing the desired SQL, restoring the
  system tables, and committing the transaction.  ALTER TABLE ...
B
Bruce Momjian 已提交
894
  TRIGGER requires a table lock so it is not ideal for this usage.
895

896
* With disabled triggers, allow pg_dump to use ALTER TABLE ADD FOREIGN KEY
897 898 899 900

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

B
Bruce Momjian 已提交
901
* Allow statement-level triggers to access modified rows
B
Bruce Momjian 已提交
902 903
* Support triggers on columns

904
  http://archives.postgresql.org/pgsql-patches/2005-07/msg00107.php
B
Bruce Momjian 已提交
905

B
Add:  
Bruce Momjian 已提交
906
* Allow AFTER triggers on system tables
B
Add:  
Bruce Momjian 已提交
907

908 909 910 911 912
  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
913

914 915
Dependency Checking
===================
B
Bruce Momjian 已提交
916

B
Update:  
Bruce Momjian 已提交
917 918 919
* Flush cached query plans when the dependent objects change,
  when the cardinality of parameters changes dramatically, or
  when new ANALYZE statistics are available
B
Bruce Momjian 已提交
920 921 922 923

  A more complex solution would be to save multiple plans for different
  cardinality and use the appropriate plan based on the EXECUTE values.

B
Add:  
Bruce Momjian 已提交
924
* Track dependencies in function bodies and recompile/invalidate
925

B
Bruce Momjian 已提交
926 927
  This is particularly important for references to temporary tables
  in PL/PgSQL because PL/PgSQL caches query plans.  The only workaround
B
Bruce Momjian 已提交
928 929 930
  in PL/PgSQL is to use EXECUTE.  One complexity is that a function
  might itself drop and recreate dependent tables, causing it to
  invalidate its own query plan.
B
Bruce Momjian 已提交
931

B
Add:  
Bruce Momjian 已提交
932

933 934
Exotic Features
===============
935

B
Bruce Momjian 已提交
936
* Add pre-parsing phase that converts non-ISO syntax to supported
937 938 939 940 941
  syntax

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

B
Bruce Momjian 已提交
942
* Allow plug-in modules to emulate features from other databases
B
Bruce Momjian 已提交
943
* SQL*Net listener that makes PostgreSQL appear as an Oracle database
B
Bruce Momjian 已提交
944
  to clients
945
* Allow statements across databases or servers with transaction
946
  semantics
947

948
  This can be done using dblink and two-phase commit.
949

B
Add:  
Bruce Momjian 已提交
950
* Add the features of packages
951

N
Neil Conway 已提交
952
	o  Make private objects accessible only to objects in the same schema
B
Add:  
Bruce Momjian 已提交
953 954 955
	o  Allow current_schema.objname to access current schema objects
	o  Add session variables
	o  Allow nested schemas
956

B
Bruce Momjian 已提交
957 958 959
* Consider allowing control of upper/lower case folding of unquoted
  identifiers

960
  http://archives.postgresql.org/pgsql-hackers/2004-04/msg00818.php
B
Bruce Momjian 已提交
961

B
Bruce Momjian 已提交
962 963 964 965 966 967 968 969 970 971 972 973
Indexes
=======

* Allow inherited tables to inherit index, UNIQUE constraint, and primary
  key, foreign key
* UNIQUE INDEX on base column not honored on INSERTs/UPDATEs from
  inherited table:  INSERT INTO inherit_table (unique_index_col) VALUES
  (dup) should fail

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

B
Add:  
Bruce Momjian 已提交
974
* Allow SELECT ... FOR UPDATE on inherited tables
B
Bruce Momjian 已提交
975 976 977 978 979 980 981 982 983 984 985 986
* Add UNIQUE capability to non-btree indexes
* Prevent index uniqueness checks when UPDATE does not modify the column

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

* Allow the creation of on-disk bitmap indexes which can be quickly
  combined with other bitmap indexes

  Such indexes could be more compact if there are only a few distinct values.
  Such indexes can also be compressed.  Keeping such indexes updated can be
  costly.
B
Bruce Momjian 已提交
987
  http://archives.postgresql.org/pgsql-patches/2005-07/msg00512.php
B
Bruce Momjian 已提交
988 989 990 991 992 993 994

* Allow use of indexes to search for NULLs

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

* Allow accurate statistics to be collected on indexes with more than
  one column or expression indexes, perhaps using per-index statistics
B
Done:  
Bruce Momjian 已提交
995
* -Add fillfactor to control reserved free space during index creation
B
Update:  
Bruce Momjian 已提交
996 997 998 999 1000 1001 1002 1003
* Allow the creation of indexes with mixed ascending/descending
  specifiers

  This is possible now by creating an operator class with reversed sort
  operators.  One complexity is that NULLs would then appear at the start
  of the result set, and this might affect certain sort types, like
  merge join.

1004
* Allow constraint_exclusion to work for UNIONs like it does for
1005 1006
  inheritance, allow it to work for UPDATE and DELETE statements, and allow
  it to be used for all statements with little performance impact
B
Add:  
Bruce Momjian 已提交
1007 1008
* Allow CREATE INDEX to take an additional parameter for use with
  special index types
B
Update:  
Bruce Momjian 已提交
1009
* Consider compressing indexes by storing key values duplicated in
B
Add:  
Bruce Momjian 已提交
1010
  several rows as a single index entry
B
Bruce Momjian 已提交
1011

B
Update:  
Bruce Momjian 已提交
1012 1013
  This is difficult because it requires datatype-specific knowledge.

B
Bruce Momjian 已提交
1014

1015 1016 1017 1018 1019
* GIST

	o Add more GIST index support for geometric data types
	o Allow GIST indexes to create certain complex index types, like
	  digital trees (see Aoki)
B
Bruce Momjian 已提交
1020 1021

* Hash
1022

B
Bruce Momjian 已提交
1023 1024
	o Pack hash index buckets onto disk pages more efficiently

B
Bruce Momjian 已提交
1025
	  Currently only one hash bucket can be stored on a page. Ideally
B
Bruce Momjian 已提交
1026 1027 1028 1029 1030 1031 1032 1033
	  several hash buckets could be stored on a single page and greater
	  granularity used for the hash algorithm.

	o Consider sorting hash buckets so entries can be found using a
	  binary search, rather than a linear scan

	o In hash indexes, consider storing the hash value with or instead
	  of the key itself
1034

B
Bruce Momjian 已提交
1035 1036 1037
	o Add WAL logging for crash recovery
	o Allow multi-column hash indexes

B
Bruce Momjian 已提交
1038

1039 1040
Fsync
=====
B
Bruce Momjian 已提交
1041

1042
* Improve commit_delay handling to reduce fsync()
B
Bruce Momjian 已提交
1043
* Determine optimal fdatasync/fsync, O_SYNC/O_DSYNC options
B
Bruce Momjian 已提交
1044 1045

  Ideally this requires a separate test program that can be run
B
Update:  
Bruce Momjian 已提交
1046 1047
  at initdb time or optionally later.  Consider O_SYNC when
  O_DIRECT exists.
B
Bruce Momjian 已提交
1048

B
Bruce Momjian 已提交
1049
* %Add an option to sync() before fsync()'ing checkpoint files
B
Add:  
Bruce Momjian 已提交
1050
* Add program to test if fsync has a delay compared to non-fsync
B
Bruce Momjian 已提交
1051

B
Bruce Momjian 已提交
1052

B
Bruce Momjian 已提交
1053 1054
Cache Usage
===========
B
Bruce Momjian 已提交
1055

B
Bruce Momjian 已提交
1056
* Allow free-behind capability for large sequential scans, perhaps using
B
Update:  
Bruce Momjian 已提交
1057 1058
  posix_fadvise()

B
Bruce Momjian 已提交
1059
  Posix_fadvise() can control both sequential/random file caching and
B
Update:  
Bruce Momjian 已提交
1060 1061 1062 1063
  free-behind behavior, but it is unclear how the setting affects other
  backends that also have the file open, and the feature is not supported
  on all operating systems.

1064 1065 1066 1067
* 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
1068 1069 1070 1071 1072
  invalidated if anyone modifies the table.  Another idea is to
  get a count directly from a unique index, but for this to be
  faster than a sequential scan it must avoid access to the heap
  to obtain tuple visibility information.

B
Add:  
Bruce Momjian 已提交
1073 1074
* Add estimated_count(*) to return an estimate of COUNT(*)

N
Neil Conway 已提交
1075
  This would use the planner ANALYZE statistics to return an estimated
B
Add:  
Bruce Momjian 已提交
1076 1077
  count.

1078 1079
* Allow data to be pulled directly from indexes

B
Bruce Momjian 已提交
1080 1081
  Currently indexes do not have enough tuple visibility information 
  to allow data to be pulled from the index without also accessing 
1082
  the heap.  One way to allow this is to set a bit on index tuples 
B
Bruce Momjian 已提交
1083 1084
  to indicate if a tuple is currently visible to all transactions 
  when the first valid heap lookup happens.  This bit would have to 
1085 1086 1087 1088 1089 1090 1091 1092
  be cleared when a heap tuple is expired.  

  Another idea is to maintain a bitmap of heap pages where all rows
  are visible to all backends, and allow index lookups to reference 
  that bitmap to avoid heap lookups, perhaps the same bitmap we might
  add someday to determine which heap pages need vacuuming.  Frequently
  accessed bitmaps would have to be stored in shared memory.  One 8k
  page of bitmaps could track 512MB of heap pages.
B
Bruce Momjian 已提交
1093

1094
* Consider automatic caching of statements at various levels:
B
Bruce Momjian 已提交
1095

B
Add:  
Bruce Momjian 已提交
1096 1097 1098 1099
	o Parsed query tree
	o Query execute plan
	o Query results

B
Add:  
Bruce Momjian 已提交
1100
* Allow sequential scans to take advantage of other concurrent
N
Neil Conway 已提交
1101
  sequential scans, also called "Synchronised Scanning"
B
Add:  
Bruce Momjian 已提交
1102

1103 1104 1105 1106
  One possible implementation is to start sequential scans from the lowest
  numbered buffer in the shared cache, and when reaching the end wrap
  around to the beginning, rather than always starting sequential scans
  at the start of the table.
B
Bruce Momjian 已提交
1107

B
Add:  
Bruce Momjian 已提交
1108 1109 1110 1111
* Consider increasing internal areas when shared buffers is increased

  http://archives.postgresql.org/pgsql-hackers/2005-10/msg01419.php

B
Update  
Bruce Momjian 已提交
1112

1113 1114
Vacuum
======
B
Bruce Momjian 已提交
1115

1116 1117
* Improve speed with indexes

N
Neil Conway 已提交
1118
  For large table adjustments during VACUUM FULL, it is faster to 
B
Bruce Momjian 已提交
1119
  reindex rather than update the index.
1120

B
Bruce Momjian 已提交
1121 1122
* Reduce lock time during VACUUM FULL by moving tuples with read lock,
  then write lock and truncate table
1123 1124 1125 1126 1127

  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.

B
Bruce Momjian 已提交
1128 1129
* Auto-fill the free space map by scanning the buffer cache or by
  checking pages written by the background writer
1130 1131

  http://archives.postgresql.org/pgsql-hackers/2006-02/msg01125.php
B
Bruce Momjian 已提交
1132
  http://archives.postgresql.org/pgsql-hackers/2006-03/msg00011.php
1133

B
Add:  
Bruce Momjian 已提交
1134 1135 1136 1137 1138 1139
* Create a bitmap of pages that need vacuuming

  Instead of sequentially scanning the entire table, have the background
  writer or some other process record pages that have expired rows, then
  VACUUM can look at just those pages rather than the entire table.  In
  the event of a system crash, the bitmap would probably be invalidated.
B
Bruce Momjian 已提交
1140 1141 1142 1143
  One complexity is that index entries still have to be vacuumed, and
  doing this without an index scan (by using the heap values to find the
  index entry) might be slow and unreliable, especially for user-defined
  index functions.
B
Add:  
Bruce Momjian 已提交
1144

B
Done:  
Bruce Momjian 已提交
1145
* -Add system view to show free space map contents
B
Add:  
Bruce Momjian 已提交
1146 1147
* Allow FSM to return free space toward the beginning of the heap file,
  in hopes that empty pages at the end can be truncated by VACUUM
B
Add:  
Bruce Momjian 已提交
1148 1149
* Allow FSM page return free space based on table clustering, to assist
  in maintaining clustering?
B
Add:  
Bruce Momjian 已提交
1150
* Consider shrinking expired tuples to just their headers
B
Bruce Momjian 已提交
1151

B
Add:  
Bruce Momjian 已提交
1152
  http://archives.postgresql.org/pgsql-patches/2006-03/msg00142.php
B
Bruce Momjian 已提交
1153

B
Bruce Momjian 已提交
1154 1155
* Allow heap reuse of UPDATEd rows if no indexed columns are changed,
  and old and new versions are on the same heap page?
B
Bruce Momjian 已提交
1156

B
Bruce Momjian 已提交
1157 1158 1159 1160
  While vacuum handles DELETEs fine, updating of non-indexed columns, like
  counters, are difficult for VACUUM to handle efficiently.  This method
  is possible for same-page updates because a single index row can be
  used to point to both old and new values.
B
Bruce Momjian 已提交
1161
  http://archives.postgresql.org/pgsql-hackers/2006-06/msg01305.php
B
Bruce Momjian 已提交
1162
  http://archives.postgresql.org/pgsql-hackers/2006-06/msg01534.php
B
Bruce Momjian 已提交
1163

B
Add:  
Bruce Momjian 已提交
1164 1165
* Reuse index tuples that point to heap tuples that are not visible to 
  anyone?
B
Add:  
Bruce Momjian 已提交
1166
* Auto-vacuum
1167

B
Add:  
Bruce Momjian 已提交
1168
	o Use free-space map information to guide refilling
B
Bruce Momjian 已提交
1169 1170
	o %Issue log message to suggest VACUUM FULL if a table is nearly
	  empty?
B
Add:  
Bruce Momjian 已提交
1171 1172
	o Improve xid wraparound detection by recording per-table rather
	  than per-database
B
Bruce Momjian 已提交
1173
	o Consider logging activity either to the logs or a system view
B
Bruce Momjian 已提交
1174
	o Turn on by default
B
Add:  
Bruce Momjian 已提交
1175

B
Bruce Momjian 已提交
1176 1177
	  http://archives.postgresql.org/pgsql-hackers/2006-08/msg01852.php

B
Bruce Momjian 已提交
1178

1179 1180
Locking
=======
1181

B
Add:  
Bruce Momjian 已提交
1182
* Fix priority ordering of read and write light-weight locks (Neil)
1183

1184

B
Bruce Momjian 已提交
1185 1186
Startup Time Improvements
=========================
B
Bruce Momjian 已提交
1187

B
Add:  
Bruce Momjian 已提交
1188
* Experiment with multi-threaded backend for backend creation [thread]
1189 1190 1191

  This would prevent the overhead associated with process creation. Most
  operating systems have trivial process creation time compared to
N
Neil Conway 已提交
1192
  database startup overhead, but a few operating systems (Win32,
B
Bruce Momjian 已提交
1193
  Solaris) might benefit from threading.  Also explore the idea of
1194
  a single session using multiple threads to execute a statement faster.
1195

B
Add:  
Bruce Momjian 已提交
1196 1197 1198
* Experiment with multi-threaded backend better resource utilization

  This would allow a single query to make use of multiple CPU's or
B
Update:  
Bruce Momjian 已提交
1199 1200 1201 1202
  multiple I/O channels simultaneously.  One idea is to create a
  background reader that can pre-fetch sequential and index scan
  pages needed by other backends.  This could be expanded to allow
  concurrent reads from multiple devices in a partitioned table.
B
Add:  
Bruce Momjian 已提交
1203

B
Bruce Momjian 已提交
1204
* Add connection pooling
1205 1206 1207 1208

  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.
1209

1210

1211 1212
Write-Ahead Log
===============
1213

1214 1215
* Eliminate need to write full pages to WAL before page modification [wal]

B
Bruce Momjian 已提交
1216
  Currently, to protect against partial disk page writes, we write
1217
  full page images to WAL before they are modified so we can correct any
1218 1219
  partial page writes during recovery.  These pages can also be
  eliminated from point-in-time archive files.
1220

B
Update:  
Bruce Momjian 已提交
1221 1222
	o  When off, write CRC to WAL and check file system blocks
	   on recovery
B
Bruce Momjian 已提交
1223 1224 1225 1226

	   If CRC check fails during recovery, remember the page in case
	   a later CRC for that page properly matches.

B
Update:  
Bruce Momjian 已提交
1227 1228 1229 1230
	o  Write full pages during file system write and not when
	   the page is modified in the buffer cache

	   This allows most full page writes to happen in the background
B
Update:  
Bruce Momjian 已提交
1231 1232 1233
	   writer.  It might cause problems for applying WAL on recovery
	   into a partially-written page, but later the full page will be
	   replaced from WAL.
B
Update:  
Bruce Momjian 已提交
1234

B
Bruce Momjian 已提交
1235
* Allow WAL traffic to be streamed to another server for stand-by
B
Add:  
Bruce Momjian 已提交
1236
  replication
1237
* Reduce WAL traffic so only modified values are written rather than
B
Bruce Momjian 已提交
1238
  entire rows?
1239 1240
* Allow the pg_xlog directory location to be specified during initdb
  with a symlink back to the /data location
B
Bruce Momjian 已提交
1241
* Allow WAL information to recover corrupted pg_controldata
1242

1243
  http://archives.postgresql.org/pgsql-patches/2006-06/msg00025.php
1244

B
Added:  
Bruce Momjian 已提交
1245 1246
* Find a way to reduce rotational delay when repeatedly writing
  last WAL page
B
Bruce Momjian 已提交
1247

1248 1249 1250
  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.
1251

B
Add:  
Bruce Momjian 已提交
1252 1253 1254 1255
* Allow buffered WAL writes and fsync

  Instead of guaranteeing recovery of all committed transactions, this
  would provide improved performance by delaying WAL writes and fsync
B
Bruce Momjian 已提交
1256
  so an abrupt operating system restart might lose a few seconds of
B
Add:  
Bruce Momjian 已提交
1257 1258 1259 1260
  committed transactions but still be consistent.  We could perhaps
  remove the 'fsync' parameter (which results in an an inconsistent
  database) in favor of this capability.

B
Bruce Momjian 已提交
1261 1262
* Allow WAL logging to be turned off for a table, but the table
  might be dropped or truncated during crash recovery [walcontrol]
B
Add:  
Bruce Momjian 已提交
1263 1264

  Allow tables to bypass WAL writes and just fsync() dirty pages on
B
Bruce Momjian 已提交
1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278
  commit.  This should be implemented using ALTER TABLE, e.g. ALTER 
  TABLE PERSISTENCE [ DROP | TRUNCATE | DEFAULT ].  Tables using 
  non-default logging should not use referential integrity with 
  default-logging tables.  A table without dirty buffers during a
  crash could perhaps avoid the drop/truncate.

* Allow WAL logging to be turned off for a table, but the table would
  avoid being truncated/dropped [walcontrol]

  To do this, only a single writer can modify the table, and writes 
  must happen only on new pages so the new pages can be removed during
  crash recovery.  Readers can continue accessing the table.  Such 
  tables probably cannot have indexes.  One complexity is the handling 
  of indexes on TOAST tables.
B
Add:  
Bruce Momjian 已提交
1279

B
Bruce Momjian 已提交
1280

1281 1282
Optimizer / Executor
====================
1283

B
Update:  
Bruce Momjian 已提交
1284
* Improve selectivity functions for geometric operators
B
Bruce Momjian 已提交
1285
* Allow ORDER BY ... LIMIT # to select high/low value without sort or
1286 1287
  index using a sequential scan for highest/lowest values

B
Bruce Momjian 已提交
1288
  Right now, if no index exists, ORDER BY ... LIMIT # requires we sort
1289 1290
  all values to return the high/low value.  Instead The idea is to do a 
  sequential scan to find the high/low value, thus avoiding the sort.
B
Bruce Momjian 已提交
1291
  MIN/MAX already does this, but not for LIMIT > 1.
1292

1293
* Precompile SQL functions to avoid overhead
B
Bruce Momjian 已提交
1294
* Create utility to compute accurate random_page_cost value
B
Bruce Momjian 已提交
1295
* Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
B
Add:  
Bruce Momjian 已提交
1296
* Have EXPLAIN ANALYZE highlight poor optimizer estimates
B
Add:  
Bruce Momjian 已提交
1297 1298
* Consider using hash buckets to do DISTINCT, rather than sorting

B
Bruce Momjian 已提交
1299 1300
  This would be beneficial when there are few distinct values.  This is
  already used by GROUP BY.
B
Bruce Momjian 已提交
1301

1302
* Log statements where the optimizer row estimates were dramatically
B
Bruce Momjian 已提交
1303
  different from the number of rows actually found?
B
Add:  
Bruce Momjian 已提交
1304 1305 1306
* Consider compressed annealing to search for query plans

  This might replace GEQO, http://sixdemonbag.org/Djinni.
B
Add:  
Bruce Momjian 已提交
1307

B
Bruce Momjian 已提交
1308

B
Bruce Momjian 已提交
1309 1310
Miscellaneous Performance
=========================
1311 1312

* Do async I/O for faster random read-ahead of data
1313 1314 1315

  Async I/O allows multiple I/O requests to be sent to the disk with
  results coming back asynchronously.
B
Bruce Momjian 已提交
1316

B
Bruce Momjian 已提交
1317
* Use mmap() rather than SYSV shared memory or to write WAL files?
1318 1319

  This would remove the requirement for SYSV SHM but would introduce
B
Bruce Momjian 已提交
1320 1321
  portability issues. Anonymous mmap (or mmap to /dev/zero) is required
  to prevent I/O overhead.
B
Bruce Momjian 已提交
1322 1323 1324

* Consider mmap()'ing files into a backend?

B
Bruce Momjian 已提交
1325 1326 1327
  Doing I/O to large tables would consume a lot of address space or
  require frequent mapping/unmapping.  Extending the file also causes
  mapping problems that might require mapping only individual pages,
B
Bruce Momjian 已提交
1328
  leading to thousands of mappings.  Another problem is that there is no
B
Bruce Momjian 已提交
1329
  way to _prevent_ I/O to disk from the dirty shared buffers so changes
B
Bruce Momjian 已提交
1330
  could hit disk before WAL is written.
1331

B
Add:  
Bruce Momjian 已提交
1332
* Add a script to ask system configuration questions and tune postgresql.conf
B
Bruce Momjian 已提交
1333 1334 1335 1336 1337 1338 1339 1340 1341
* Merge xmin/xmax/cmin/cmax back into three header fields

  Before subtransactions, there used to be only three fields needed to
  store these four values. This was possible because only the current
  transaction looks at the cmin/cmax values. If the current transaction
  created and expired the row the fields stored where xmin (same as
  xmax), cmin, cmax, and if the transaction was expiring a row from a
  another transaction, the fields stored were xmin (cmin was not
  needed), xmax, and cmax. Such a system worked because a transaction
B
Bruce Momjian 已提交
1342
  could only see rows from another completed transaction. However,
B
Bruce Momjian 已提交
1343 1344 1345 1346 1347
  subtransactions can see rows from outer transactions, and once the
  subtransaction completes, the outer transaction continues, requiring
  the storage of all four fields. With subtransactions, an outer
  transaction can create a row, a subtransaction expire it, and when the
  subtransaction completes, the outer transaction still has to have
B
Bruce Momjian 已提交
1348
  proper visibility of the row's cmin, for example, for cursors.
B
Bruce Momjian 已提交
1349 1350

  One possible solution is to create a phantom cid which represents a
B
Bruce Momjian 已提交
1351 1352
  cmin/cmax pair and is stored in local memory.  Another idea is to
  store both cmin and cmax only in local memory.
B
Bruce Momjian 已提交
1353

B
Bruce Momjian 已提交
1354 1355 1356
* Consider ways of storing rows more compactly on disk

	o Support a smaller header for short variable-length fields?
B
Bruce Momjian 已提交
1357

1358 1359 1360 1361 1362 1363
	  One idea is to create zero-or-one-byte-header versions 
	  of varlena data types.  In involves setting the high-bit and 
	  0-127 length in the single-byte header, or clear the high bit
	  and store the 7-bit ASCII value in the rest of the byte.
	  The small-header versions have no alignment requirements.
	  http://archives.postgresql.org/pgsql-hackers/2006-09/msg01372.php
B
Bruce Momjian 已提交
1364

B
Bruce Momjian 已提交
1365
	o Reduce the row header size?
1366

B
Add:  
Bruce Momjian 已提交
1367

1368
Source Code
1369 1370
===========

B
Bruce Momjian 已提交
1371
* Add use of 'const' for variables in source tree
B
Bruce Momjian 已提交
1372
* Move some things from /contrib into main tree
B
Bruce Momjian 已提交
1373
* Move some /contrib modules out to their own project sites
B
Bruce Momjian 已提交
1374 1375 1376 1377

  Particularly, move GPL-licensed /contrib/userlock and 
  /contrib/dbmirror/clean_pending.pl.

B
Bruce Momjian 已提交
1378
* %Remove warnings created by -Wcast-align
B
Bruce Momjian 已提交
1379
* Move platform-specific ps status display info from ps_status.c to ports
B
Bruce Momjian 已提交
1380
* Add optional CRC checksum to heap and index pages
B
Bruce Momjian 已提交
1381
* Improve documentation to build only interfaces (Marc)
1382
* Remove or relicense modules that are not under the BSD license, if possible
B
Bruce Momjian 已提交
1383
* %Remove memory/file descriptor freeing before ereport(ERROR)
B
Add:  
Bruce Momjian 已提交
1384
* Acquire lock on a relation before building a relcache entry for it
B
Bruce Momjian 已提交
1385 1386
* %Promote debug_query_string into a server-side function current_query()
* %Allow the identifier length to be increased via a configure option
B
Add:  
Bruce Momjian 已提交
1387
* Allow cross-compiling by generating the zic database on the target system
N
Neil Conway 已提交
1388
* Improve NLS maintenance of libpgport messages linked onto applications
B
Add:  
Bruce Momjian 已提交
1389
* Allow ecpg to work with MSVC and BCC
B
Add:  
Bruce Momjian 已提交
1390
* Add xpath_array() to /contrib/xml2 to return results as an array
B
Bruce Momjian 已提交
1391 1392 1393 1394 1395
* Allow building in directories containing spaces

  This is probably not possible because 'gmake' and other compiler tools
  do not fully support quoting of paths with spaces.

B
Done:  
Bruce Momjian 已提交
1396
* -Allow installing to directories containing spaces
B
Bruce Momjian 已提交
1397 1398 1399 1400 1401

  This is possible if proper quoting is added to the makefiles for the
  install targets.  Because PostgreSQL supports relocatable installs, it
  is already possible to install into a directory that doesn't contain 
  spaces and then copy the install to a directory with spaces.
B
Bruce Momjian 已提交
1402

B
Add:  
Bruce Momjian 已提交
1403
* Fix sgmltools so PDFs can be generated with bookmarks
N
Neil Conway 已提交
1404
* -%Clean up compiler warnings (especially with gcc version 4)
B
Add:  
Bruce Momjian 已提交
1405 1406
* Use UTF8 encoding for NLS messages so all server encodings can
  read them properly
B
Add:  
Bruce Momjian 已提交
1407
* Update Bonjour to work with newer cross-platform SDK
B
Done:  
Bruce Momjian 已提交
1408
* -Remove BeOS and QNX-specific code
B
Add:  
Bruce Momjian 已提交
1409 1410
* Split out libpq pgpass and environment documentation sections to make
  it easier for non-developers to find
B
Add:  
Bruce Momjian 已提交
1411 1412 1413 1414
* Improve port/qsort() to handle sorts with 50% unique and 50% duplicate
  value [qsort]

  This involves choosing better pivot points for the quicksort.
B
Add:  
Bruce Momjian 已提交
1415

B
Add:  
Bruce Momjian 已提交
1416
* Consider detoasting keys before sorting
B
Bruce Momjian 已提交
1417 1418
* Consider GnuTLS if OpenSSL license becomes a problem

1419
  http://archives.postgresql.org/pgsql-patches/2006-05/msg00040.php
B
Bruce Momjian 已提交
1420

B
Added:  
Bruce Momjian 已提交
1421

1422
* Win32
1423

1424 1425 1426 1427 1428 1429 1430
	o Remove configure.in check for link failure when cause is found
	o Remove readdir() errno patch when runtime/mingwex/dirent.c rev
	  1.4 is released
	o Remove psql newline patch when we find out why mingw outputs an
	  extra newline
	o Allow psql to use readline once non-US code pages work with
	  backslashes
B
Add:  
Bruce Momjian 已提交
1431 1432
	o Re-enable timezone output on log_line_prefix '%t' when a
	  shorter timezone string is available
B
Add:  
Bruce Momjian 已提交
1433
	o Fix problem with shared memory on the Win32 Terminal Server
1434 1435
	o Improve signal handling

B
Add:  
Bruce Momjian 已提交
1436
	  http://archives.postgresql.org/pgsql-patches/2005-06/msg00027.php
1437

B
Add:  
Bruce Momjian 已提交
1438 1439 1440 1441
	o Add long file support for binary pg_dump output

	  While Win32 supports 64-bit files, the MinGW API does not,
	  meaning we have to build an fseeko replacement on top of the
B
Update:  
Bruce Momjian 已提交
1442 1443 1444
	  Win32 API, and we have to make sure MinGW handles it.  Another
	  option is to wait for the MinGW project to fix it, or use the
	  code from the LibGW32C project as a guide.
B
Bruce Momjian 已提交
1445

B
Done:  
Bruce Momjian 已提交
1446
	o -Port contrib/xml2
B
Bruce Momjian 已提交
1447
	o Check WSACancelBlockingCall() for interrupts [win32intr]
B
Bruce Momjian 已提交
1448

B
Bruce Momjian 已提交
1449

B
Add:  
Bruce Momjian 已提交
1450
* Wire Protocol Changes
1451

1452
	o Allow dynamic character set handling
B
Add:  
Bruce Momjian 已提交
1453
	o Add decoded type, length, precision
1454
	o Use compression?
B
Bruce Momjian 已提交
1455
	o Update clients to use data types, typmod, schema.table.column names
1456
	  of result sets using new statement protocol
B
Add:  
Bruce Momjian 已提交
1457

1458

1459 1460 1461
Features We Do _Not_ Want
=========================

B
Bruce Momjian 已提交
1462
* All backends running as threads in a single process (not wanted)
1463 1464 1465 1466 1467

  This eliminates the process protection we get from the current setup.
  Thread creation is usually the same overhead as process creation on
  modern systems, so it seems unwise to use a pure threaded model.

B
Bruce Momjian 已提交
1468
* Optimizer hints (not wanted)
1469 1470 1471 1472 1473

  Optimizer hints are used to work around problems in the optimizer.  We
  would rather have the problems reported and fixed.
  http://archives.postgresql.org/pgsql-hackers/2006-08/msg00506.php

B
Bruce Momjian 已提交
1474 1475 1476 1477 1478 1479
* Allow AS in "SELECT col AS label" to be optional (not wanted)

  Because we support postfix operators, it isn't possible to make AS
  optional and continue to use bison.
  http://archives.postgresql.org/pgsql-sql/2006-08/msg00164.php

1480

B
Bruce Momjian 已提交
1481 1482 1483 1484 1485
---------------------------------------------------------------------------


Developers who have claimed items are:
--------------------------------------
B
Bruce Momjian 已提交
1486
* Alvaro is Alvaro Herrera <alvherre@dcc.uchile.cl>
B
Bruce Momjian 已提交
1487
* Andrew is Andrew Dunstan <andrew@dunslane.net>
B
Bruce Momjian 已提交
1488
* Bruce is Bruce Momjian <bruce@momjian.us> of EnterpriseDB
B
Bruce Momjian 已提交
1489 1490 1491
* Christopher is Christopher Kings-Lynne <chriskl@familyhealth.com.au> of
    Family Health Network
* D'Arcy is D'Arcy J.M. Cain <darcy@druid.net> of The Cain Gang Ltd.
B
Bruce Momjian 已提交
1492
* David is David Fetter <david@fetter.org>
B
Bruce Momjian 已提交
1493
* Fabien is Fabien Coelho <coelho@cri.ensmp.fr>
B
Bruce Momjian 已提交
1494 1495
* 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
1496
* Jan is Jan Wieck <JanWieck@Yahoo.com> of Afilias, Inc.
B
Bruce Momjian 已提交
1497
* Joe is Joe Conway <mail@joeconway.com>
1498
* Karel is Karel Zak <zakkr@zf.jcu.cz>
B
Fix :  
Bruce Momjian 已提交
1499
* Magnus is Magnus Hagander <mha@sollentuna.net>
B
Bruce Momjian 已提交
1500
* Marc is Marc Fournier <scrappy@hub.org> of PostgreSQL, Inc.
B
Bruce Momjian 已提交
1501
* Matthew T. O'Connor <matthew@zeut.net>
B
Bruce Momjian 已提交
1502
* Michael is Michael Meskes <meskes@postgresql.org> of Credativ
B
Bruce Momjian 已提交
1503
* Neil is Neil Conway <neilc@samurai.com>
B
Bruce Momjian 已提交
1504
* Oleg is Oleg Bartunov <oleg@sai.msu.su>
B
Bruce Momjian 已提交
1505
* Pavel is Pavel Stehule <pavel.stehule@hotmail.com>
1506
* Peter is Peter Eisentraut <peter_e@gmx.net>
B
Bruce Momjian 已提交
1507
* Philip is Philip Warner <pjw@rhyme.com.au> of Albatross Consulting Pty. Ltd.
B
Bruce Momjian 已提交
1508
* Rod is Rod Taylor <pg@rbt.ca>
B
Bruce Momjian 已提交
1509
* Simon is Simon Riggs <simon@2ndquadrant.com>
B
Bruce Momjian 已提交
1510
* Stephan is Stephan Szabo <sszabo@megazone23.bigpanda.com>
B
Bruce Momjian 已提交
1511
* Tatsuo is Tatsuo Ishii <ishii@sraoss.co.jp> of SRA OSS, Inc. Japan
B
Bruce Momjian 已提交
1512
* Teodor is Teodor Sigaev <teodor@sigaev.ru>
B
Bruce Momjian 已提交
1513
* Tom is Tom Lane <tgl@sss.pgh.pa.us> of Red Hat