TODO 30.0 KB
Newer Older
B
Bruce Momjian 已提交
1
TODO list for PostgreSQL
B
Bruce Momjian 已提交
2
========================
B
Bruce Momjian 已提交
3
#A dash (-) marks changes that will appear in the upcoming 7.5 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
Bruce Momjian 已提交
8
Last updated:		Sun Aug  1 10:08:04 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 82 83 84 85 86 87

  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.

* 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
88

B
Bruce Momjian 已提交
89 90
* Improve replication solutions
	o Automatic failover
91 92 93 94 95

	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
96
	o Load balancing
97 98 99 100 101

	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
102
	o Allow replication over unreliable or non-persistent links
B
Add:  
Bruce Momjian 已提交
103

B
Bruce Momjian 已提交
104

105 106
Data Types
==========
B
Bruce Momjian 已提交
107 108

* Remove Money type, add money formatting for decimal type
B
Bruce Momjian 已提交
109
* -Change factorial to return a numeric (Gavin)
B
Add:  
Bruce Momjian 已提交
110
* Change NUMERIC to enforce the maximum precision, and increase it
111 112
* 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
113
* Add transaction_timestamp(), statement_timestamp(), clock_timestamp() functionality
114 115 116 117 118 119 120 121 122

  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
123
* Allow infinite dates just like infinite timestamps
B
Bruce Momjian 已提交
124 125
* -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
126
* Have initdb set DateStyle based on locale?
B
Add:  
Bruce Momjian 已提交
127
* Add pg_get_acldef(), pg_get_typedefault(), and pg_get_attrdef()
128
* Allow to_char to print localized month names
B
Add:  
Bruce Momjian 已提交
129
* Allow functions to have a search path specified at creation time
B
Bruce Momjian 已提交
130
* -Make LENGTH() of CHAR() not count trailing spaces
B
Add:  
Bruce Momjian 已提交
131
* Allow substring/replace() to get/set bit values
B
Add:  
Bruce Momjian 已提交
132
* Add GUC variable to allow output of interval values in ISO8601 format
133
* -Support composite types as table columns
B
Add:  
Bruce Momjian 已提交
134
* Fix data types where equality comparison isn't intuitive, e.g. box
B
Add:  
Bruce Momjian 已提交
135

B
Bruce Momjian 已提交
136

137
* ARRAYS
B
Bruce Momjian 已提交
138
	o Allow nulls in arrays
B
Bruce Momjian 已提交
139
	o Allow MIN()/MAX() on arrays
B
Bruce Momjian 已提交
140
	o Delay resolution of array expression type so assignment coercion 
141
	  can be performed on empty array expressions
B
Bruce Momjian 已提交
142 143 144
	o Modify array literal representation to handle array index lower bound
	  of other than one

B
Bruce Momjian 已提交
145

B
Bruce Momjian 已提交
146
* BINARY DATA
147
	o Improve vacuum of large objects, like /contrib/vacuumlo (?)
B
Bruce Momjian 已提交
148
	o Add security checking for large objects
149 150 151 152

	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
153
	o Auto-delete large objects when referencing row is deleted
B
Bruce Momjian 已提交
154

155 156 157 158
	o Allow read/write into TOAST values like large objects

	This requires the TOAST column to be stored EXTERNAL.

159

160 161
Multi-Language Support
======================
B
Bruce Momjian 已提交
162

163
* Add NCHAR (as distinguished from ordinary varchar),
B
Update:  
Bruce Momjian 已提交
164
* Allow locale to be set at database creation
165 166 167 168 169 170 171 172

  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
173
* Support multiple simultaneous character sets, per SQL92
174 175 176 177
* 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
178
  data from being interpreted as encoded strings
B
Done:  
Bruce Momjian 已提交
179
* -Fix upper()/lower() to work for multibyte encodings
B
Add:  
Bruce Momjian 已提交
180

181

182 183
Views / Rules
=============
B
Bruce Momjian 已提交
184

B
Bruce Momjian 已提交
185
* Automatically create rules on views so they are updateable, per SQL92 [view]
B
Bruce Momjian 已提交
186
* Add the functionality for WITH CHECK OPTION clause of CREATE VIEW
B
Bruce Momjian 已提交
187
* Allow NOTIFY in rules involving conditionals
B
Bruce Momjian 已提交
188
* Have views on temporary tables exist in the temporary namespace
B
Add:  
Bruce Momjian 已提交
189
* Allow temporary views on non-temporary tables
B
Bruce Momjian 已提交
190
* Allow RULE recompilation
191

B
Add:  
Bruce Momjian 已提交
192

193 194
Indexes
=======
B
Bruce Momjian 已提交
195

196
* -Order duplicate index entries on creation by ctid for faster heap lookups
B
Bruce Momjian 已提交
197 198
* Allow inherited tables to inherit index, UNIQUE constraint, and primary
  key, foreign key  [inheritance]
199 200 201 202 203 204 205
* 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
206
* Add UNIQUE capability to non-btree indexes
B
Bruce Momjian 已提交
207
* Add rtree index support for line, lseg, path, point
208 209 210 211 212 213
* 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
214
* Use index to restrict rows returned by multi-key index when used with
215 216 217 218 219 220 221
  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
222
* Prevent index uniqueness checks when UPDATE does not modify the column
223 224 225 226 227 228 229 230 231 232 233

  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
234
* Use bitmaps to combine existing indexes [performance]
235 236 237 238 239

  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
240
* Allow use of indexes to search for NULLs
241 242 243

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

B
Bruce Momjian 已提交
244
* -Allow SELECT * FROM tab WHERE int2col = 4 to use int2col index, int8,
B
Bruce Momjian 已提交
245
  float4, numeric/decimal too
B
Reword:  
Bruce Momjian 已提交
246
* Add concurrency to GIST
B
Reword:  
Bruce Momjian 已提交
247
* Pack hash index buckets onto disk pages more efficiently
B
Bruce Momjian 已提交
248

249 250 251 252
  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
253

254 255
Commands
========
B
Bruce Momjian 已提交
256

257
* Add BETWEEN ASYMMETRIC/SYMMETRIC
B
Add:  
Bruce Momjian 已提交
258
* Change LIMIT/OFFSET to use int8
B
Bruce Momjian 已提交
259
* CREATE TABLE AS can not determine column lengths from expressions [atttypmod]
260 261
* Allow UPDATE to handle complex aggregates [update] (?)
* -Allow command blocks to ignore certain types of errors
B
Added:  
Bruce Momjian 已提交
262
* Allow backslash handling in quoted strings to be disabled for portability
263 264 265 266 267 268 269 270 271 272 273

  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
274
* Add CORRESPONDING BY to UNION/INTERSECT/EXCEPT
275
* Allow REINDEX to rebuild all database indexes, remove /contrib/reindex
B
Add:  
Bruce Momjian 已提交
276
* Add ROLLUP, CUBE, GROUPING SETS options to GROUP BY
277 278 279
* 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
280
* Allow UPDATE tab SET ROW (col, ...) = (...) for updating multiple columns
281 282
* 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
283
* -Add NO WAIT LOCKs
B
Add:  
Bruce Momjian 已提交
284
* Allow TRUNCATE ... CASCADE/RESTRICT
B
Add:  
Bruce Momjian 已提交
285
* Allow PREPARE of cursors
286 287 288 289 290 291 292
* 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
293
* -COMMENT ON [ CAST | CONVERSION | OPERATOR CLASS | LARGE OBJECT | LANGUAGE ] 
B
Update:  
Bruce Momjian 已提交
294
  (Christopher) 
B
Added:  
Bruce Momjian 已提交
295
* Dump large object comments in custom dump format
B
Bruce Momjian 已提交
296
* Add optional textual message to NOTIFY
297 298 299 300 301

  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
302
* -Allow more ISOLATION LEVELS to be accepted
B
Add:  
Bruce Momjian 已提交
303
* Allow CREATE TABLE foo (f1 INT CHECK (f1 > 0) CHECK (f1 < 10)) to work
304 305 306 307 308 309 310 311 312
  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
313
* -Have psql \dn show only visible temp schemas using current_schemas()
B
Done:  
Bruce Momjian 已提交
314
* -Have psql '\i ~/<tab><tab>' actually load files it displays from home dir
315 316
* Ignore temporary tables from other sessions when processing
  inheritance?
B
Bruce Momjian 已提交
317
* -Add GUC setting to make created tables default to WITHOUT OIDS
318 319 320
* 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
321
* Add MERGE command that does UPDATE/DELETE, or on failure, INSERT (rules, triggers?)
B
Add:  
Bruce Momjian 已提交
322
* Add ON COMMIT capability to CREATE TABLE AS SELECT
B
Add:  
Bruce Momjian 已提交
323
* Add NOVICE output level for helpful messages like automatic sequence/index creation
B
Add:  
Bruce Momjian 已提交
324

B
Bruce Momjian 已提交
325
* ALTER
B
Done:  
Bruce Momjian 已提交
326 327
	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
328
	  rows with DEFAULT value
B
Done:  
Bruce Momjian 已提交
329
	o -ALTER TABLE ADD COLUMN column SERIAL doesn't create sequence because
B
Bruce Momjian 已提交
330
          of the item above
331
	o Have ALTER TABLE RENAME rename SERIAL sequence names
B
Done:  
Bruce Momjian 已提交
332
	o -Allow ALTER TABLE to modify column lengths and change to binary
B
Add:  
Bruce Momjian 已提交
333
	  compatible types
334
	o -Add ALTER DATABASE ... OWNER TO newowner
B
Add:  
Bruce Momjian 已提交
335
	o Add ALTER DOMAIN TYPE
B
Add:  
Bruce Momjian 已提交
336
	o Allow ALTER TABLE ... ALTER CONSTRAINT ... RENAME
B
Add:  
Bruce Momjian 已提交
337
	o Allow ALTER TABLE to change constraint deferrability and actions
B
Add:  
Bruce Momjian 已提交
338
	o Disallow dropping of an inherited constraint
339 340 341 342 343 344 345 346 347 348 349
	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
350

B
Bruce Momjian 已提交
351
* CLUSTER
B
Bruce Momjian 已提交
352
	o Automatically maintain clustering on a table
353 354 355 356 357 358

	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
359
	o Add default clustering to system tables
B
Bruce Momjian 已提交
360

361 362 363
	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
364
* COPY
B
Done:  
Bruce Momjian 已提交
365
	o -Allow dump/load of CSV format
366 367 368 369 370 371 372
	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
373

B
Bruce Momjian 已提交
374
* CURSOR
375 376 377 378 379 380 381 382 383 384 385 386 387 388
	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
389

B
Bruce Momjian 已提交
390
* INSERT
391
	o Allow INSERT/UPDATE of the system-generated oid value for a row
B
Bruce Momjian 已提交
392
	o Allow INSERT INTO tab (col1, ..) VALUES (val1, ..), (val2, ..)
393 394 395 396 397
	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
398

B
Bruce Momjian 已提交
399
* SHOW/SET
B
Bruce Momjian 已提交
400
	o Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM
B
Bruce Momjian 已提交
401
	  ANALYZE, and CLUSTER
402 403 404 405 406 407 408 409
	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
410

B
Bruce Momjian 已提交
411
* SERVER-SIDE LANGUAGES
412 413 414 415
	o Allow PL/PgSQL's RAISE function to take expressions (?)

	Currently only constants are supported.

B
Bruce Momjian 已提交
416
	o Change PL/PgSQL to use palloc() instead of malloc()
B
Done:  
Bruce Momjian 已提交
417
	o -Allow Java server-side programming
418 419 420 421 422 423 424 425
	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
426
	o -Allow PL/pgSQL parameters to be specified by name and type during definition
B
Bruce Momjian 已提交
427
	o Allow function parameters to be passed by name,
B
Added:  
Bruce Momjian 已提交
428
	  get_employee_salary(emp_id => 12345, tax_year => 2001)
429 430
	o Add Oracle-style packages
	o Add table function support to pltcl, plperl, plpython (?)
B
Add:  
Bruce Momjian 已提交
431
	o Allow PL/pgSQL to name columns by ordinal position, e.g. rec.(3)
B
Add:  
Bruce Momjian 已提交
432
	o Allow PL/pgSQL EXECUTE query_var INTO record_var;
B
Bruce Momjian 已提交
433
	o Add capability to create and call PROCEDURES
B
Add:  
Bruce Momjian 已提交
434
	o Allow PL/pgSQL to handle %TYPE arrays, e.g. tab.col%TYPE[]
B
Bruce Momjian 已提交
435

B
Add:  
Bruce Momjian 已提交
436

437 438
Clients
=======
B
Bruce Momjian 已提交
439

440 441 442 443 444 445
* 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
446
* -Allow psql \du to show users, and add \dg for groups
B
Add:  
Bruce Momjian 已提交
447
* Add a libpq function to support Parse/DescribeStatement capability
448
* Prevent libpq's PQfnumber() from lowercasing the column name (?)
B
Done:  
Bruce Momjian 已提交
449
* -Allow pg_dump to dump CREATE CONVERSION (Christopher)
B
Done:  
Bruce Momjian 已提交
450
* -Make pg_restore continue after errors, so it acts more like pg_dump scripts
B
Bruce Momjian 已提交
451
* Have psql show current values for a sequence
B
Add:  
Bruce Momjian 已提交
452
* Allow pg_dumpall to use non-text output formats
B
Add:  
Bruce Momjian 已提交
453
* Have pg_dump use multi-statement transactions for INSERT dumps
B
Bruce Momjian 已提交
454
* Move psql backslash database information into the backend, use mnemonic
B
Add:  
Bruce Momjian 已提交
455
  commands? [psql]
456 457 458 459

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

B
Add:  
Bruce Momjian 已提交
460
* Allow pg_dump to use multiple -t and -n switches
461 462 463

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

B
Add:  
Bruce Momjian 已提交
464
* Fix oid2name and dbsize for tablespaces
465
* Consistently display privilege information for all objects in psql
B
Bruce Momjian 已提交
466

467
* ECPG (?)
M
Michael Meskes 已提交
468
	o Docs
469 470 471 472 473 474 475

	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
476
	o Add a semantic check level, e.g. check if a table really exists
B
Bruce Momjian 已提交
477
	o fix handling of DB attributes that are arrays
B
Bruce Momjian 已提交
478
	o Use backend PREPARE/EXECUTE facility for ecpg where possible
B
Update:  
Bruce Momjian 已提交
479
	o Implement SQLDA
M
Michael Meskes 已提交
480 481
	o Fix nested C comments
	o sqlwarn[6] should be 'W' if the PRECISION or SCALE value specified
482
	o Make SET CONNECTION thread-aware, non-standard?
483
	o Allow multidimensional arrays
B
Bruce Momjian 已提交
484

B
Bruce Momjian 已提交
485

486 487
Referential Integrity
=====================
B
Bruce Momjian 已提交
488

B
Bruce Momjian 已提交
489
* Add MATCH PARTIAL referential integrity
490 491 492 493 494 495 496
* 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
497
* Enforce referential integrity for system tables
B
Bruce Momjian 已提交
498
* Change foreign key constraint for array -> element to mean element
499 500
  in array (?)
* Allow DEFERRABLE UNIQUE constraints (?)
B
Add:  
Bruce Momjian 已提交
501
* Allow triggers to be disabled [trigger]
502 503 504 505

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

506
* With disabled triggers, allow pg_dump to use ALTER TABLE ADD FOREIGN KEY
507 508 509 510

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

B
Bruce Momjian 已提交
511
* Allow statement-level triggers to access modified rows
512
* Support triggers on columns
B
Add:  
Bruce Momjian 已提交
513 514
* 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
515
* -Print table names with constraint names in error messages, or make constraint
B
Add:  
Bruce Momjian 已提交
516
  names unique within a schema
B
Done:  
Bruce Momjian 已提交
517
* -Issue NOTICE if foreign key data requires costly test to match primary key
B
Add:  
Bruce Momjian 已提交
518
* Remove CREATE CONSTRAINT TRIGGER
519 520 521 522

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

B
Add:  
Bruce Momjian 已提交
523
* Allow AFTER triggers on system tables
B
Add:  
Bruce Momjian 已提交
524

525 526 527 528 529
  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
530

531 532
Dependency Checking
===================
B
Bruce Momjian 已提交
533

534
* Flush cached query plans when the dependent objects change
B
Done:  
Bruce Momjian 已提交
535
* -Use dependency information to dump data in proper order
B
Bruce Momjian 已提交
536
* -Have pg_dump -c clear the database using dependency information
537

B
Add:  
Bruce Momjian 已提交
538

539 540
Exotic Features
===============
541

542 543 544 545 546 547 548 549
* 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
550
* Allow plug-in modules to emulate features from other databases
B
Bruce Momjian 已提交
551
* SQL*Net listener that makes PostgreSQL appear as an Oracle database
B
Bruce Momjian 已提交
552
  to clients
553 554 555 556 557 558 559 560 561 562 563 564
* 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
565

B
Bruce Momjian 已提交
566

B
Bruce Momjian 已提交
567
PERFORMANCE
568 569
===========

B
Bruce Momjian 已提交
570

571 572
Fsync
=====
B
Bruce Momjian 已提交
573

574
* Improve commit_delay handling to reduce fsync()
B
Bruce Momjian 已提交
575
* Determine optimal fdatasync/fsync, O_SYNC/O_DSYNC options
576 577
* 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
578

B
Bruce Momjian 已提交
579

580 581
Cache
=====
B
Bruce Momjian 已提交
582
* Add free-behind capability for large sequential scans [fadvise]
B
Bruce Momjian 已提交
583
* Consider use of open/fcntl(O_DIRECT) to minimize OS caching
584 585 586 587 588 589 590 591 592 593 594 595 596
* 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
597

598

599 600
Vacuum
======
B
Bruce Momjian 已提交
601

602 603 604 605 606
* 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
607
* Reduce lock time by moving tuples with read lock, then write
B
Bruce Momjian 已提交
608
  lock and truncate table
609 610 611 612 613 614

  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
615
  rather than in /contrib (Matthew)
B
Add:  
Bruce Momjian 已提交
616
* Allow free space map to be auto-sized or warn when it is too small
617 618 619 620 621 622 623

  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
624

B
Add:  
Bruce Momjian 已提交
625

626 627
Locking
=======
628 629

* Make locking of shared data structures more fine-grained
630 631 632 633

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

634
* Add code to detect an SMP machine and handle spinlocks accordingly
B
Bruce Momjian 已提交
635 636
  from distributted.net, http://www1.distributed.net/source, 
  in client/common/cpucheck.cpp
637 638 639 640 641 642 643 644 645 646 647

  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.

648 649
* Research use of sched_yield() for spinlock acquisition failure

650

651 652
Startup Time
============
B
Bruce Momjian 已提交
653

B
Bruce Momjian 已提交
654
* Experiment with multi-threaded backend [thread]
655 656 657 658 659 660

  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
661
* Add connection pooling [pool]
662 663 664 665

  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.
666

667

668 669
Write-Ahead Log
===============
670

671 672 673 674 675 676 677 678 679 680 681 682
* 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
683
* Add WAL index reliability improvement to non-btree indexes
684 685 686
* 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
687
* Allow WAL information to recover corrupted pg_controldata
B
Added:  
Bruce Momjian 已提交
688 689
* Find a way to reduce rotational delay when repeatedly writing
  last WAL page
690 691 692 693
  
  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.
694

B
Bruce Momjian 已提交
695

696 697
Optimizer / Executor
====================
698

699 700 701 702 703 704 705 706
* 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
707
* Add utility to compute accurate random_page_cost value
B
Bruce Momjian 已提交
708
* Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
B
Update:  
Bruce Momjian 已提交
709
* Allow sorting, temp files, temp tables to use multiple work directories
710 711

  This allows the I/O load to be spread across multiple disk drives.
B
Add:  
Bruce Momjian 已提交
712
* Have EXPLAIN ANALYZE highlight poor optimizer estimates
713 714 715 716 717
* 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
718

B
Add:  
Bruce Momjian 已提交
719

720 721
Miscellaneous
=============
722 723

* Do async I/O for faster random read-ahead of data
724 725 726 727

  Async I/O allows multiple I/O requests to be sent to the disk with
  results coming back asynchronously.
    
728
* Use mmap() rather than SYSV shared memory or to write WAL files (?) [mmap]
729 730 731 732 733

  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
734
* Add a script to ask system configuration questions and tune postgresql.conf
735
* -Use background process to write dirty shared buffers to disk
B
Add:  
Bruce Momjian 已提交
736 737
* Use a phantom command counter for nested subtransactions to reduce
  tuple overhead
B
Add:  
Bruce Momjian 已提交
738

739

740
Source Code
741 742
===========

B
Bruce Momjian 已提交
743
* Add use of 'const' for variables in source tree
B
Bruce Momjian 已提交
744
* Rename some /contrib modules from pg* to pg_*
B
Bruce Momjian 已提交
745
* Move some things from /contrib into main tree
B
Bruce Momjian 已提交
746
* Remove warnings created by -Wcast-align
B
Bruce Momjian 已提交
747
* Move platform-specific ps status display info from ps_status.c to ports
B
Typo.  
Bruce Momjian 已提交
748
* Improve access-permissions check on data directory in Cygwin (Tom)
B
Bruce Momjian 已提交
749
* Add optional CRC checksum to heap and index pages
B
Bruce Momjian 已提交
750
* -Change representation of whole-tuple parameters to functions
B
Add:  
Bruce Momjian 已提交
751
* Clarify use of 'application' and 'command' tags in SGML docs
B
Bruce Momjian 已提交
752
* Better document ability to build only certain interfaces (Marc)
753
* Remove or relicense modules that are not under the BSD license, if possible
754
* Remove memory/file descriptor freeing before ereport(ERROR)
B
Add:  
Bruce Momjian 已提交
755
* Acquire lock on a relation before building a relcache entry for it
B
Add:  
Bruce Momjian 已提交
756
* Research interaction of setitimer() and sleep() used by statement_timeout
B
Bruce Momjian 已提交
757
* -Add checks for fclose() failure (Tom)
B
Done:  
Bruce Momjian 已提交
758
* -Change CVS ID to PostgreSQL
B
Done:  
Bruce Momjian 已提交
759
* -Exit postmaster if postgresql.conf can not be opened
B
Add:  
Bruce Momjian 已提交
760
* Rename /scripts directory because they are all C programs now
B
Add:  
Bruce Momjian 已提交
761
* Promote debug_query_string into a server-side function current_query()
B
Add:  
Bruce Momjian 已提交
762
* Allow the identifier length to be increased via a configure option
B
Add:  
Bruce Momjian 已提交
763
* Allow binaries to be statically linked so they are more easily relocated
B
Add:  
Bruce Momjian 已提交
764

765

B
Add:  
Bruce Momjian 已提交
766
* Wire Protocol Changes
767
	o Allow dynamic character set handling
B
Add:  
Bruce Momjian 已提交
768
	o Add decoded type, length, precision
769
	o Use compression?
B
Bruce Momjian 已提交
770 771
	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
772

773

B
Bruce Momjian 已提交
774 775 776 777 778
---------------------------------------------------------------------------


Developers who have claimed items are:
--------------------------------------
B
Bruce Momjian 已提交
779
* Alvaro is Alvaro Herrera <alvherre@dcc.uchile.cl>
B
Bruce Momjian 已提交
780
* Andrew is Andrew Dunstan <andrew@dunslane.net>
B
Bruce Momjian 已提交
781 782 783
* 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
784
* Claudio is Claudio Natoli <claudio.natoli@memetrics.com>
B
Bruce Momjian 已提交
785
* D'Arcy is D'Arcy J.M. Cain <darcy@druid.net> of The Cain Gang Ltd.
B
Bruce Momjian 已提交
786
* Fabien is Fabien Coelho <coelho@cri.ensmp.fr>
B
Bruce Momjian 已提交
787 788
* 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
789
* Hiroshi is Hiroshi Inoue <Inoue@tpf.co.jp>
B
Bruce Momjian 已提交
790
* Jan is Jan Wieck <JanWieck@Yahoo.com> of Afilias, Inc.
B
Bruce Momjian 已提交
791
* Joe is Joe Conway <mail@joeconway.com>
792 793
* Karel is Karel Zak <zakkr@zf.jcu.cz>
* Kris is Kris Jurka 
B
Fix :  
Bruce Momjian 已提交
794
* Magnus is Magnus Hagander <mha@sollentuna.net>
B
Bruce Momjian 已提交
795
* Marc is Marc Fournier <scrappy@hub.org> of PostgreSQL, Inc.
B
Bruce Momjian 已提交
796
* Matthew T. O'Connor <matthew@zeut.net>
B
Bruce Momjian 已提交
797
* Michael is Michael Meskes <meskes@postgresql.org> of Credativ
B
Bruce Momjian 已提交
798
* Neil is Neil Conway <neilc@samurai.com>
B
Bruce Momjian 已提交
799
* Oleg is Oleg Bartunov <oleg@sai.msu.su>
800
* Peter is Peter Eisentraut <peter_e@gmx.net>
B
Bruce Momjian 已提交
801
* Philip is Philip Warner <pjw@rhyme.com.au> of Albatross Consulting Pty. Ltd.
B
Bruce Momjian 已提交
802
* Rod is Rod Taylor <pg@rbt.ca>
803
* Simon is Simon Riggs
B
Bruce Momjian 已提交
804
* Stephan is Stephan Szabo <sszabo@megazone23.bigpanda.com>
B
Bruce Momjian 已提交
805
* Tatsuo is Tatsuo Ishii <t-ishii@sra.co.jp> of Software Research Assoc.
806
* Teodor is 
B
Bruce Momjian 已提交
807
* Tom is Tom Lane <tgl@sss.pgh.pa.us> of Red Hat