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9 <h1><a name="section_1">PostgreSQL TODO List</a></h1>
10 <p>Current maintainer: Bruce Momjian (<a href="mailto:bruce@momjian.us">bruce@momjian.us</a>)<br/>
11 Last updated: Mon Mar 10 10:16:29 EDT 2008
13 <p>The most recent version of this document can be viewed at<br/>
14 <a href="http://www.postgresql.org/docs/faqs.TODO.html">http://www.postgresql.org/docs/faqs.TODO.html</a>.
16 <p><strong>A hyphen, "-", marks changes that will appear in the upcoming 8.3 release.</strong><br/>
17 <strong>A percent sign, "%", marks items that are easier to implement.</strong>
19 <p>Bracketed items, "[<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?"></a>]", have more detail.
21 <p>This list contains all known PostgreSQL bugs and feature requests. If<br/>
22 you would like to work on an item, please read the Developer's FAQ<br/>
23 first. There is also a developer's wiki at<br/>
24 <a href="http://developer.postgresql.org">http://developer.postgresql.org</a>.
26 <h1><a name="section_2">Administration</a></h1>
29 <li>Allow administrators to safely terminate individual sessions either
30 via an SQL function or SIGTERM
31 <p> Lock table corruption following SIGTERM of an individual backend
32 has been reported in 8.0. A possible cause was fixed in 8.1, but
33 it is unknown whether other problems exist. This item mostly
34 requires additional testing rather than of writing any new code.
36 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-08/msg00174.php">http://archives.postgresql.org/pgsql-hackers/2006-08/msg00174.php</a>
38 </li><li>Check for unreferenced table files created by transactions that were
39 in-progress when the server terminated abruptly
40 <p> <a href="http://archives.postgresql.org/pgsql-patches/2006-06/msg00096.php">http://archives.postgresql.org/pgsql-patches/2006-06/msg00096.php</a>
42 </li><li>Set proper permissions on non-system schemas during db creation
43 <p> Currently all schemas are owned by the super-user because they are copied
44 from the template1 database. However, since all objects are inherited
45 from the template database, it is not clear that setting schemas to the db
48 </li><li>Add function to report the time of the most recent server reload
49 </li><li>Allow statistics collector information to be pulled from the collector
50 process directly, rather than requiring the collector to write a
51 filesystem file twice a second?
52 </li><li>Allow log_min_messages to be specified on a per-module basis
53 <p> This would allow administrators to see more detailed information from
54 specific sections of the backend, e.g. checkpoints, autovacuum, etc.
55 Another idea is to allow separate configuration files for each module,
56 or allow arbitrary SET commands to be passed to them.
58 </li><li>Simplify ability to create partitioned tables
59 <p> This would allow creation of partitioned tables without requiring
60 creation of triggers or rules for INSERT/UPDATE/DELETE, and constraints
61 for rapid partition selection. Options could include range and hash
64 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg00375.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg00375.php</a>
65 <a href="http://archives.postgresql.org/pgsql-hackers/2007-04/msg00151.php">http://archives.postgresql.org/pgsql-hackers/2007-04/msg00151.php</a>
67 </li><li>Allow auto-selection of partitioned tables for min/max() operations
68 </li><li>Allow more complex user/database default GUC settings
69 <p> Currently ALTER USER and ALTER DATABASE support per-user and
70 per-database defaults. Consider adding per-user-and-database
71 defaults so things like search_path can be defaulted for a
72 specific user connecting to a specific database.
74 </li><li>Allow custom variable classes that can restrict who can set the values
75 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-11/msg00911.php">http://archives.postgresql.org/pgsql-hackers/2006-11/msg00911.php</a>
77 </li><li>Implement the SQL standard mechanism whereby REVOKE ROLE revokes only
78 the privilege granted by the invoking role, and not those granted
80 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2007-05/msg00010.php">http://archives.postgresql.org/pgsql-bugs/2007-05/msg00010.php</a>
82 </li><li>Allow SSL authentication/encryption over unix domain sockets
83 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-12/msg00924.php">http://archives.postgresql.org/pgsql-hackers/2007-12/msg00924.php</a>
85 </li><li>Allow client certificate names to be checked against the client
87 <p> This is already implemented in
88 libpq/fe-secure.c::verify_peer_name_matches_certificate() but the code
91 </li><li>Configuration files
93 <li>Allow pg_hba.conf to specify host names along with IP addresses
94 <p> Host name lookup could occur when the postmaster reads the
95 pg_hba.conf file, or when the backend starts. Another
96 solution would be to reverse lookup the connection IP and
97 check that hostname against the host names in pg_hba.conf.
98 We could also then check that the host name maps to the IP
101 </li><li>%Allow postgresql.conf file values to be changed via an SQL
102 API, perhaps using SET GLOBAL
103 </li><li>Allow the server to be stopped/restarted via an SQL API
104 </li><li>Issue a warning if a change-on-restart-only postgresql.conf value
105 is modified and the server config files are reloaded
109 <li>Allow a database in tablespace t1 with tables created in
110 tablespace t2 to be used as a template for a new database created
111 with default tablespace t2
112 <p> Currently all objects in the default database tablespace must
113 have default tablespace specifications. This is because new
114 databases are created by copying directories. If you mix default
115 tablespace tables and tablespace-specified tables in the same
116 directory, creating a new database from such a mixed directory
117 would create a new database with tables that had incorrect
118 explicit tablespaces. To fix this would require modifying
119 pg_class in the newly copied database, which we don't currently
122 </li><li>Allow reporting of which objects are in which tablespaces
123 <p> This item is difficult because a tablespace can contain objects
124 from multiple databases. There is a server-side function that
125 returns the databases which use a specific tablespace, so this
126 requires a tool that will call that function and connect to each
127 database to find the objects in each database for that tablespace.
129 </li><li>Allow WAL replay of CREATE TABLESPACE to work when the directory
130 structure on the recovery computer is different from the original
131 </li><li>Allow per-tablespace quotas
133 </li><li>Point-In-Time Recovery (PITR)
135 <li>Allow a warm standby system to also allow read-only statements
136 [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?pitr">pitr</a>]
137 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg00050.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg00050.php</a>
139 </li><li>%Create dump tool for write-ahead logs for use in determining
140 transaction id for point-in-time recovery
141 <p> This is useful for checking PITR recovery.
143 </li><li>Allow recovery.conf to support the same syntax as
144 postgresql.conf, including quoting
145 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00497.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00497.php</a>
149 <h1><a name="section_3">Data Types</a></h1>
152 <li>Change NUMERIC to enforce the maximum precision
153 </li><li>Reduce storage space for small NUMERICs
154 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg01331.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg01331.php</a>
155 <a href="http://archives.postgresql.org/pgsql-patches/2007-02/msg00505.php">http://archives.postgresql.org/pgsql-patches/2007-02/msg00505.php</a>
157 </li><li>Fix data types where equality comparison isn't intuitive, e.g. box
158 </li><li>Add support for public SYNONYMs
159 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-03/msg00519.php">http://archives.postgresql.org/pgsql-hackers/2006-03/msg00519.php</a>
161 </li><li>Fix CREATE CAST on DOMAINs
162 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-05/msg00072.php">http://archives.postgresql.org/pgsql-hackers/2006-05/msg00072.php</a>
163 <a href="http://archives.postgresql.org/pgsql-hackers/2006-09/msg01681.php">http://archives.postgresql.org/pgsql-hackers/2006-09/msg01681.php</a>
165 </li><li>Add support for SQL-standard GENERATED/IDENTITY columns
166 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-07/msg00543.php">http://archives.postgresql.org/pgsql-hackers/2006-07/msg00543.php</a>
167 <a href="http://archives.postgresql.org/pgsql-hackers/2006-08/msg00038.php">http://archives.postgresql.org/pgsql-hackers/2006-08/msg00038.php</a>
168 <a href="http://archives.postgresql.org/pgsql-hackers/2007-05/msg00344.php">http://archives.postgresql.org/pgsql-hackers/2007-05/msg00344.php</a>
169 <a href="http://archives.postgresql.org/pgsql-patches/2007-05/msg00076.php">http://archives.postgresql.org/pgsql-patches/2007-05/msg00076.php</a>
170 <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg00604.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg00604.php</a>
172 </li><li>Improve XML support
173 <p> <a href="http://developer.postgresql.org/index.php/XML_Support">http://developer.postgresql.org/index.php/XML_Support</a>
175 </li><li>Consider placing all sequences in a single table, or create a system
177 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-03/msg00008.php">http://archives.postgresql.org/pgsql-hackers/2008-03/msg00008.php</a>
179 </li><li>Allow the UUID type to accept non-standard formats
180 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg01214.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg01214.php</a>
182 </li><li>Allow text search dictionary to filter out only stop words
183 <p> <a href="http://archives.postgresql.org/pgsql-patches/2007-11/msg00081.php">http://archives.postgresql.org/pgsql-patches/2007-11/msg00081.php</a>
185 </li><li>Consider a function-based API for '@@' full text searches
186 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg00511.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg00511.php</a>
188 </li><li>Dates and Times
190 <li>Allow infinite dates and intervals just like infinite timestamps
191 </li><li>Merge hardwired timezone names with the TZ database; allow either
192 kind everywhere a TZ name is currently taken
193 </li><li>Allow TIMESTAMP WITH TIME ZONE to store the original timezone
194 information, either zone name or offset from UTC [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?timezone">timezone</a>]
195 <p> If the TIMESTAMP value is stored with a time zone name, interval
196 computations should adjust based on the time zone rules.
198 </li><li>Fix SELECT '0.01 years'::interval, '0.01 months'::interval
199 </li><li>Add a GUC variable to allow output of interval values in ISO8601
201 </li><li>Have timestamp subtraction not call justify_hours()?
202 <p> <a href="http://archives.postgresql.org/pgsql-sql/2006-10/msg00059.php">http://archives.postgresql.org/pgsql-sql/2006-10/msg00059.php</a>
204 </li><li>Improve timestamptz subtraction to be DST-aware
205 <p> Currently subtracting one date from another that crosses a
206 daylight savings time adjustment can return '1 day 1 hour', but
207 adding that back to the first date returns a time one hour in
208 the future. This is caused by the adjustment of '25 hours' to
209 '1 day 1 hour', and '1 day' is the same time the next day, even
210 if daylight savings adjustments are involved.
212 </li><li>Fix interval display to support values exceeding 2^31 hours
213 </li><li>Add overflow checking to timestamp and interval arithmetic
214 </li><li>Extend timezone code to allow 64-bit values so we can
215 represent years beyond 2038
216 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-09/msg01363.php">http://archives.postgresql.org/pgsql-hackers/2006-09/msg01363.php</a>
218 </li><li>Use LC_TIME for localized weekday/month names, rather than
220 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-11/msg00390.php">http://archives.postgresql.org/pgsql-hackers/2006-11/msg00390.php</a>
222 </li><li>Add ISO INTERVAL handling
225 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-01/msg00250.php">http://archives.postgresql.org/pgsql-hackers/2006-01/msg00250.php</a><br/>
226 <a href="http://archives.postgresql.org/pgsql-bugs/2006-04/msg00248.php">http://archives.postgresql.org/pgsql-bugs/2006-04/msg00248.php</a>
229 <li>Support ISO INTERVAL syntax if units cannot be determined from
230 the string, and are supplied after the string
231 <p> The SQL standard states that the units after the string
232 specify the units of the string, e.g. INTERVAL '2' MINUTE
233 should return '00:02:00'. The current behavior has the units
234 restrict the interval value to the specified unit or unit
235 range, INTERVAL '70' SECOND returns '00:00:10'.
237 <p> For syntax that isn't uniquely ISO or PG syntax, like '1' or
238 '1:30', treat as ISO if there is a range specification clause,
239 and as PG if there no clause is present, e.g. interpret '1:30'
240 MINUTE TO SECOND as '1 minute 30 seconds', and interpret
241 '1:30' as '1 hour, 30 minutes'.
243 <p> This makes common cases like SELECT INTERVAL '1' MONTH
244 SQL-standard results. The SQL standard supports a limited
245 number of unit combinations and doesn't support unit names in
246 the string. The PostgreSQL syntax is more flexible in the
247 range of units supported, e.g. PostgreSQL supports '1 year 1
248 hour', while the SQL standard does not.
250 </li><li>Add support for year-month syntax, INTERVAL '50-6' YEAR
252 </li><li>Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1
253 year' AS INTERVAL MONTH), and this should return '12 months'
254 </li><li>Round or truncate values to the requested precision, e.g.
255 INTERVAL '11 months' AS YEAR should return one or zero
256 </li><li>Support precision, CREATE TABLE foo (a INTERVAL MONTH(3))
260 <li>Delay resolution of array expression's data type so assignment
261 coercion can be performed on empty array expressions
262 </li><li>Add support for arrays of domains
263 <p> <a href="http://archives.postgresql.org/pgsql-patches/2007-05/msg00114.php">http://archives.postgresql.org/pgsql-patches/2007-05/msg00114.php</a>
265 </li><li>Allow single-byte header storage for array elements
269 <li>Improve vacuum of large objects, like contrib/vacuumlo?
270 </li><li>Add security checking for large objects
271 </li><li>Auto-delete large objects when referencing row is deleted
272 <p> contrib/lo offers this functionality.
274 </li><li>Allow read/write into TOAST values like large objects
275 <p> This requires the TOAST column to be stored EXTERNAL.
277 </li><li>Add API for 64-bit large object access
278 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-09/msg00781.php">http://archives.postgresql.org/pgsql-hackers/2005-09/msg00781.php</a>
281 </li><li>MONEY data type
283 <li>Add locale-aware MONEY type, and support multiple currencies
284 <p> <a href="http://archives.postgresql.org/pgsql-general/2005-08/msg01432.php">http://archives.postgresql.org/pgsql-general/2005-08/msg01432.php</a>
285 <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg01181.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg01181.php</a>
287 </li><li>MONEY dumps in a locale-specific format making it difficult to
288 restore to a system with a different locale
289 </li><li>Allow MONEY to be easily cast to/from other numeric data types
293 <h1><a name="section_4">Functions</a></h1>
296 <li>Allow INET subnet tests using non-constants to be indexed
297 </li><li>Allow to_date() and to_timestamp() accept localized month names
298 </li><li>Fix to_date()-related functions to consistently issue errors
299 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg00915.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg00915.php</a>
301 </li><li>Add missing parameter handling in to_char()
302 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-12/msg00948.php">http://archives.postgresql.org/pgsql-hackers/2005-12/msg00948.php</a>
304 </li><li>Allow substring/replace() to get/set bit values
305 </li><li>Allow to_char() on interval values to accumulate the highest unit
307 <p> Some special format flag would be required to request such
308 accumulation. Such functionality could also be added to EXTRACT.
309 Prevent accumulation that crosses the month/day boundary because of
310 the uneven number of days in a month.
313 <li>to_char(INTERVAL '1 hour 5 minutes', 'MI') => 65
314 </li><li>to_char(INTERVAL '43 hours 20 minutes', 'MI' ) => 2600
315 </li><li>to_char(INTERVAL '43 hours 20 minutes', 'WK:DD:HR:MI') => 0:1:19:20
316 </li><li>to_char(INTERVAL '3 years 5 months','MM') => 41
318 </li><li>Implement inlining of set-returning functions defined in SQL
319 </li><li>Allow SQL-language functions to return results from RETURNING queries
320 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-10/msg00665.php">http://archives.postgresql.org/pgsql-hackers/2006-10/msg00665.php</a>
322 </li><li>Allow SQL-language functions to reference parameters by parameter name
323 <p> Currently SQL-language functions can only refer to dollar parameters,
326 </li><li>Add SPI_gettypmod() to return the typemod for a TupleDesc
327 </li><li>Enforce typmod for function inputs, function results and parameters for
328 spi_prepare'd statements called from PLs
329 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg01403.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg01403.php</a>
331 </li><li>Allow holdable cursors in SPI
332 </li><li>Tighten function permission checks
333 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00568.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00568.php</a>
335 </li><li>Fix IS OF so it matches the ISO specification, and add documentation
336 <p> <a href="http://archives.postgresql.org/pgsql-patches/2003-08/msg00060.php">http://archives.postgresql.org/pgsql-patches/2003-08/msg00060.php</a>
337 <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg00060.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg00060.php</a>
339 </li><li>Add missing operators for geometric data types
340 <p> Some geometric types do not have the full suite of geometric operators,
343 </li><li>Implement Boyer-Moore searching in strpos()
344 <p> <a href="http://archives.postgresql.org/pgsql-patches/2007-08/msg00012.php">http://archives.postgresql.org/pgsql-patches/2007-08/msg00012.php</a>
346 </li><li>Prevent malicious functions from being executed with the permissions
347 of unsuspecting users
348 <p> Index functions are safe, so VACUUM and ANALYZE are safe too.
349 Triggers, CHECK and DEFAULT expressions, and rules are still vulnerable.
350 <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00268.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00268.php</a>
352 </li><li>Reduce memory usage of aggregates in set returning functions
353 <p> <a href="http://archives.postgresql.org/pgsql-performance/2008-01/msg00031.php">http://archives.postgresql.org/pgsql-performance/2008-01/msg00031.php</a>
356 <h1><a name="section_5">Multi-Language Support</a></h1>
359 <li>Add NCHAR (as distinguished from ordinary varchar),
360 </li><li>Allow locale to be set at database creation
361 <p> Currently locale can only be set during initdb. No global tables have
362 locale-aware columns. However, the database template used during
363 database creation might have locale-aware indexes. The indexes would
364 need to be reindexed to match the new locale.
366 </li><li>Allow encoding on a per-column basis optionally using the ICU library:
367 <p> Right now only one encoding is allowed per database. [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?locale">locale</a>]
369 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-03/msg00932.php">http://archives.postgresql.org/pgsql-hackers/2005-03/msg00932.php</a>
370 <a href="http://archives.postgresql.org/pgsql-patches/2005-08/msg00309.php">http://archives.postgresql.org/pgsql-patches/2005-08/msg00309.php</a>
371 <a href="http://archives.postgresql.org/pgsql-patches/2006-03/msg00233.php">http://archives.postgresql.org/pgsql-patches/2006-03/msg00233.php</a>
372 <a href="http://archives.postgresql.org/pgsql-hackers/2006-09/msg00662.php">http://archives.postgresql.org/pgsql-hackers/2006-09/msg00662.php</a>
374 </li><li>Add CREATE COLLATE? [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?locale">locale</a>]
375 </li><li>Support multiple simultaneous character sets, per SQL92
376 </li><li>Improve UTF8 combined character handling?
377 </li><li>Add octet_length_server() and octet_length_client()
378 </li><li>Make octet_length_client() the same as octet_length()?
379 </li><li>Fix problems with wrong runtime encoding conversion for NLS message files
380 </li><li>Add URL to more complete multi-byte regression tests
381 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-07/msg00272.php">http://archives.postgresql.org/pgsql-hackers/2005-07/msg00272.php</a>
383 </li><li>Fix ILIKE and regular expressions to handle case insensitivity
384 properly in multibyte encodings
385 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2005-10/msg00001.php">http://archives.postgresql.org/pgsql-bugs/2005-10/msg00001.php</a>
386 <a href="http://archives.postgresql.org/pgsql-patches/2005-11/msg00173.php">http://archives.postgresql.org/pgsql-patches/2005-11/msg00173.php</a>
388 </li><li>Set client encoding based on the client operating system encoding
389 <p> Currently client_encoding is set in postgresql.conf, which
390 defaults to the server encoding.
391 <a href="http://archives.postgresql.org/pgsql-hackers/2006-08/msg01696.php">http://archives.postgresql.org/pgsql-hackers/2006-08/msg01696.php</a>
394 <h1><a name="section_6">Views / Rules</a></h1>
397 <li>Automatically create rules on views so they are updateable, per SQL99
398 <p> We can only auto-create rules for simple views. For more complex
399 cases users will still have to write rules manually.
401 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-03/msg00586.php">http://archives.postgresql.org/pgsql-hackers/2006-03/msg00586.php</a>
402 <a href="http://archives.postgresql.org/pgsql-patches/2006-08/msg00255.php">http://archives.postgresql.org/pgsql-patches/2006-08/msg00255.php</a>
404 </li><li>Add the functionality for WITH CHECK OPTION clause of CREATE VIEW
405 </li><li>Allow NOTIFY in rules involving conditionals
406 </li><li>Allow VIEW/RULE recompilation when the underlying tables change
407 <p> Another issue is whether underlying table changes should be reflected
408 in the view, e.g. should SELECT * show additional columns if they
409 are added after the view is created.
411 </li><li>Make it possible to use RETURNING together with conditional DO INSTEAD
412 rules, such as for partitioning setups
413 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-09/msg00577.php">http://archives.postgresql.org/pgsql-hackers/2007-09/msg00577.php</a>
415 </li><li>Add the ability to automatically create materialized views
416 <p> Right now materialized views require the user to create triggers on the
417 main table to keep the summary table current. SQL syntax should be able
418 to manager the triggers and summary table automatically. A more
419 sophisticated implementation would automatically retrieve from the
420 summary table when the main table is referenced, if possible.
423 <h1><a name="section_7">SQL Commands</a></h1>
426 <li>Add CORRESPONDING BY to UNION/INTERSECT/EXCEPT
427 </li><li>Add ROLLUP, CUBE, GROUPING SETS options to GROUP BY
428 </li><li>%Allow SET CONSTRAINTS to be qualified by schema/table name
429 </li><li>%Add a separate TRUNCATE permission
430 <p> Currently only the owner can TRUNCATE a table because triggers are not
431 called, and the table is locked in exclusive mode.
433 </li><li>Allow PREPARE of cursors
434 </li><li>Allow finer control over the caching of prepared query plans
435 <p> Currently queries prepared via the libpq API are planned on first
436 execute using the supplied parameters --- allow SQL PREPARE to do the
437 same. Also, allow control over replanning prepared queries either
438 manually or automatically when statistics for execute parameters
439 differ dramatically from those used during planning.
441 </li><li>Improve logging of prepared transactions recovered during startup
442 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-11/msg00092.php">http://archives.postgresql.org/pgsql-hackers/2006-11/msg00092.php</a>
444 </li><li>Allow LISTEN/NOTIFY to store info in memory rather than tables?
445 <p> Currently LISTEN/NOTIFY information is stored in pg_listener. Storing
446 such information in memory would improve performance.
448 </li><li>Add optional textual message to NOTIFY
449 <p> This would allow an informational message to be added to the notify
450 message, perhaps indicating the row modified or other custom
453 </li><li>Allow multiple identical NOTIFY events to always be communicated to the
454 client, rather than sent as a single notification to the listener
455 <p> <a href="http://archives.postgresql.org/pgsql-general/2008-01/msg00057.php">http://archives.postgresql.org/pgsql-general/2008-01/msg00057.php</a>
457 </li><li>Add a GUC variable to warn about non-standard SQL usage in queries
458 </li><li>Add SQL-standard MERGE command, typically used to merge two tables
459 [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?merge">merge</a>]
460 <p> This is similar to UPDATE, then for unmatched rows, INSERT.
461 Whether concurrent access allows modifications which could cause
462 row loss is implementation independent.
464 </li><li>Add REPLACE or UPSERT command that does UPDATE, or on failure, INSERT
465 [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?merge">merge</a>]
466 <p> To implement this cleanly requires that the table have a unique index
467 so duplicate checking can be easily performed. It is possible to
468 do it without a unique index if we require the user to LOCK the table
471 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-11/msg00501.php">http://archives.postgresql.org/pgsql-hackers/2005-11/msg00501.php</a>
472 <a href="http://archives.postgresql.org/pgsql-hackers/2005-11/msg00536.php">http://archives.postgresql.org/pgsql-hackers/2005-11/msg00536.php</a>
474 </li><li>Add NOVICE output level for helpful messages like automatic sequence/index
476 </li><li>Add GUC to issue notice about statements that use unjoined tables
477 </li><li>Allow EXPLAIN to identify tables that were skipped because of
479 </li><li>Allow EXPLAIN output to be more easily processed by scripts, perhaps XML
480 </li><li>Enable standard_conforming_strings
481 </li><li>Make standard_conforming_strings the default in 8.5?
482 <p> When this is done, backslash-quote should be prohibited in non-E''
483 strings because of possible confusion over how such strings treat
484 backslashes. Basically, '' is always safe for a literal single
485 quote, while \' might or might not be based on the backslash
488 </li><li>Simplify dropping roles that have objects in several databases
489 </li><li>Allow COMMENT ON to accept an expression rather than just a string
490 </li><li>Allow the count returned by SELECT, etc to be represented as an int64
491 to allow a higher range of values
492 </li><li>Add SQL99 WITH clause to SELECT
493 </li><li>Add SQL:2003 WITH RECURSIVE (hierarchical) queries to SELECT
494 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg01375.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg01375.php</a>
495 <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg00642.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg00642.php</a>
496 <a href="http://archives.postgresql.org/pgsql-patches/2007-03/msg00139.php">http://archives.postgresql.org/pgsql-patches/2007-03/msg00139.php</a>
498 </li><li>Add DEFAULT .. AS OWNER so permission checks are done as the table
500 <p> This would be useful for SERIAL nextval() calls and CHECK constraints.
502 </li><li>Allow DISTINCT to work in multiple-argument aggregate calls
503 </li><li>Add column to pg_stat_activity that shows the progress of long-running
504 commands like CREATE INDEX and VACUUM
505 </li><li>Implement SQL:2003 window functions
506 </li><li>Improve failure message when DROP DATABASE is used on a database that
507 has prepared transactions
508 </li><li>Allow INSERT/UPDATE ... RETURNING inside a SELECT 'FROM' clause
509 <p> <a href="http://archives.postgresql.org/pgsql-general/2006-09/msg00803.php">http://archives.postgresql.org/pgsql-general/2006-09/msg00803.php</a>
510 <a href="http://archives.postgresql.org/pgsql-hackers/2006-10/msg00693.php">http://archives.postgresql.org/pgsql-hackers/2006-10/msg00693.php</a>
512 </li><li>Increase locking when DROPing objects so dependent objects cannot
513 get dropped while the DROP operation is happening
514 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg00937.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg00937.php</a>
516 </li><li>-<em>Allow AS in "SELECT col AS label" to be optional in certain cases</em>
517 </li><li>Allow INSERT ... DELETE ... RETURNING, namely allow the DELETE ...
518 RETURNING to supply values to the INSERT
519 <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/thrd2.php#00979">http://archives.postgresql.org/pgsql-hackers/2008-02/thrd2.php#00979</a>
520 </li><li>Add comments on system tables/columns using the information in
522 <p> Ideally the information would be pulled from the SGML file
527 <li>Allow CREATE TABLE AS to determine column lengths for complex
528 expressions like SELECT col1 || col2
529 </li><li>Have WITH CONSTRAINTS also create constraint indexes
530 <p> <a href="http://archives.postgresql.org/pgsql-patches/2007-04/msg00149.php">http://archives.postgresql.org/pgsql-patches/2007-04/msg00149.php</a>
532 </li><li>Have CONSTRAINT cname NOT NULL record the contraint name
533 <p> Right now pg_attribute.attnotnull records the NOT NULL status
534 of the column, but does not record the contraint name
539 <li>Allow UPDATE tab SET ROW (col, ...) = (SELECT...)
540 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-07/msg01306.php">http://archives.postgresql.org/pgsql-hackers/2006-07/msg01306.php</a>
541 <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg00865.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg00865.php</a>
543 </li><li>Research self-referential UPDATEs that see inconsistent row versions
544 in read-committed mode
545 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-05/msg00507.php">http://archives.postgresql.org/pgsql-hackers/2007-05/msg00507.php</a>
546 <a href="http://archives.postgresql.org/pgsql-hackers/2007-06/msg00016.php">http://archives.postgresql.org/pgsql-hackers/2007-06/msg00016.php</a>
548 </li><li>Allow GLOBAL temporary tables to exist as empty by default in
550 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-07/msg00006.php">http://archives.postgresql.org/pgsql-hackers/2007-07/msg00006.php</a>
555 <li>Have ALTER TABLE RENAME rename SERIAL sequence names
556 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-03/msg00008.php">http://archives.postgresql.org/pgsql-hackers/2008-03/msg00008.php</a>
558 </li><li>Have ALTER SEQUENCE RENAME rename the sequence name stored
559 in the sequence table
560 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2007-09/msg00092.php">http://archives.postgresql.org/pgsql-bugs/2007-09/msg00092.php</a>
561 <a href="http://archives.postgresql.org/pgsql-bugs/2007-10/msg00007.php">http://archives.postgresql.org/pgsql-bugs/2007-10/msg00007.php</a>
562 <a href="http://archives.postgresql.org/pgsql-hackers/2008-03/msg00008.php">http://archives.postgresql.org/pgsql-hackers/2008-03/msg00008.php</a>
564 </li><li>Add ALTER DOMAIN to modify the underlying data type
565 </li><li>%Allow ALTER TABLE ... ALTER CONSTRAINT ... RENAME
566 <p> <a href="http://archives.postgresql.org/pgsql-patches/2006-02/msg00168.php">http://archives.postgresql.org/pgsql-patches/2006-02/msg00168.php</a>
568 </li><li>%Allow ALTER TABLE to change constraint deferrability and actions
569 </li><li>Add missing object types for ALTER ... SET SCHEMA
570 </li><li>Allow ALTER TABLESPACE to move to different directories
571 </li><li>Allow databases to be moved to different tablespaces
572 </li><li>Allow moving system tables to other tablespaces, where possible
573 <p> Currently non-global system tables must be in the default database
574 tablespace. Global system tables can never be moved.
576 </li><li>Prevent parent tables from altering or dropping constraints
577 like CHECK that are inherited by child tables unless CASCADE
579 </li><li>%Prevent child tables from altering or dropping constraints
580 like CHECK that were inherited from the parent table
581 </li><li>Have ALTER INDEX update the name of a constraint using that index
582 </li><li>Add ALTER TABLE RENAME CONSTRAINT, update index name also
583 </li><li>Allow column display reordering by recording a display,
584 storage, and permanent id for every column?
585 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00782.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00782.php</a>
590 <li>Automatically maintain clustering on a table
591 <p> This might require some background daemon to maintain clustering
592 during periods of low usage. It might also require tables to be only
593 partially filled for easier reorganization. Another idea would
594 be to create a merged heap/index data file so an index lookup would
595 automatically access the heap data too. A third idea would be to
596 store heap rows in hashed groups, perhaps using a user-supplied
598 <a href="http://archives.postgresql.org/pgsql-performance/2004-08/msg00349.php">http://archives.postgresql.org/pgsql-performance/2004-08/msg00349.php</a>
600 </li><li>%Add default clustering to system tables
601 <p> To do this, determine the ideal cluster index for each system
602 table and set the cluster setting during initdb.
604 </li><li>%Add VERBOSE option to report tables as they are processed,
609 <li>Allow COPY to report error lines and continue
610 <p> This requires the use of a savepoint before each COPY line is
611 processed, with ROLLBACK on COPY failure.
613 </li><li>Allow COPY on a newly-created table to skip WAL logging
614 <p> On crash recovery, the table involved in the COPY would
615 be removed or have its heap and index files truncated. One
616 issue is that no other backend should be able to add to
617 the table at the same time, which is something that is
618 currently allowed. This currently is done if the table is
619 created inside the same transaction block as the COPY because
620 no other backends can see the table.
622 </li><li>Consider using a ring buffer for COPY FROM
623 <p> <a href="http://archives.postgresql.org/pgsql-patches/2008-02/msg00140.php">http://archives.postgresql.org/pgsql-patches/2008-02/msg00140.php</a>
624 <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg01080.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg01080.php</a>
626 </li><li>Allow COPY FROM to create index entries in bulk
627 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg00811.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg00811.php</a>
630 </li><li>GRANT/REVOKE
632 <li>Allow column-level privileges
633 </li><li>%Allow GRANT/REVOKE permissions to be applied to all schema objects
635 <p> The proposed syntax is:
636 </p><p> GRANT SELECT ON ALL TABLES IN public TO phpuser;
637 GRANT SELECT ON NEW TABLES IN public TO phpuser;
639 </li><li>Allow GRANT/REVOKE permissions to be inherited by objects based on
641 </li><li>Allow SERIAL sequences to inherit permissions from the base table?
645 <li>Prevent DROP TABLE from dropping a row referenced by its own open
650 <li>Allow INSERT/UPDATE of the system-generated oid value for a row
651 </li><li>In rules, allow VALUES() to contain a mixture of 'old' and 'new'
656 <li>Add SET PERFORMANCE_TIPS option to suggest INDEX, VACUUM, VACUUM
660 <h1><a name="section_8">Referential Integrity</a></h1>
663 <li>Add MATCH PARTIAL referential integrity
664 </li><li>Change foreign key constraint for array -> element to mean element
666 </li><li>Fix problem when cascading referential triggers make changes on
667 cascaded tables, seeing the tables in an intermediate state
668 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-09/msg00174.php">http://archives.postgresql.org/pgsql-hackers/2005-09/msg00174.php</a>
669 <a href="http://archives.postgresql.org/pgsql-hackers/2005-09/msg00174.php">http://archives.postgresql.org/pgsql-hackers/2005-09/msg00174.php</a>
671 </li><li>Allow DEFERRABLE and end-of-statement UNIQUE constraints?
672 <p> This would allow UPDATE tab SET col = col + 1 to work if col has
673 a unique index. Currently, uniqueness checks are done while the
674 command is being executed, rather than at the end of the statement
676 <a href="http://people.planetpostgresql.org/greg/index.php?/archives/2006/06/10.html">http://people.planetpostgresql.org/greg/index.php?/archives/2006/06/10.html</a>
677 <a href="http://archives.postgresql.org/pgsql-hackers/2006-09/msg01458.php">http://archives.postgresql.org/pgsql-hackers/2006-09/msg01458.php</a>
679 </li><li>Improve referential integrity checks
680 <p> <a href="http://archives.postgresql.org/pgsql-performance/2005-10/msg00458.php">http://archives.postgresql.org/pgsql-performance/2005-10/msg00458.php</a>
683 <h1><a name="section_9">Server-Side Languages</a></h1>
688 <li>Fix RENAME to work on variables other than OLD/NEW
689 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2002-03/msg00591.php">http://archives.postgresql.org/pgsql-hackers/2002-03/msg00591.php</a>
690 <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg01615.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg01615.php</a>
691 <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg01587.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg01587.php</a>
693 </li><li>Allow function parameters to be passed by name,
694 get_employee_salary(12345 AS emp_id, 2001 AS tax_year)
695 </li><li>Allow handling of %TYPE arrays, e.g. tab.col%TYPE[<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?"></a>]
696 </li><li>Allow listing of record column names, and access to
697 record columns via variables, e.g. columns := r.(*),
699 <p> <a href="http://archives.postgresql.org/pgsql-patches/2005-07/msg00458.php">http://archives.postgresql.org/pgsql-patches/2005-07/msg00458.php</a>
700 <a href="http://archives.postgresql.org/pgsql-patches/2006-05/msg00302.php">http://archives.postgresql.org/pgsql-patches/2006-05/msg00302.php</a>
701 <a href="http://archives.postgresql.org/pgsql-patches/2006-06/msg00031.php">http://archives.postgresql.org/pgsql-patches/2006-06/msg00031.php</a>
703 </li><li>Add support for SCROLL cursors
704 </li><li>Add support for WITH HOLD cursors
705 </li><li>Allow row and record variables to be set to NULL constants,
706 and allow NULL tests on such variables
707 <p> Because a row is not scalar, do not allow assignment
708 from NULL-valued scalars.
710 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-10/msg00070.php">http://archives.postgresql.org/pgsql-hackers/2006-10/msg00070.php</a>
715 <li>Add table function support to pltcl, plpythonu
716 </li><li>Add support for polymorphic arguments and return types to
717 languages other than PL/PgSQL
718 </li><li>Add capability to create and call PROCEDURES
719 </li><li>Add support for OUT and INOUT parameters to languages other
721 </li><li>Add PL/PythonU tracebacks
722 <p> <a href="http://archives.postgresql.org/pgsql-patches/2006-02/msg00288.php">http://archives.postgresql.org/pgsql-patches/2006-02/msg00288.php</a>
724 </li><li>Allow data to be passed in native language formats, rather
726 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-05/msg00289.php">http://archives.postgresql.org/pgsql-hackers/2007-05/msg00289.php</a>
730 <h1><a name="section_10">Clients</a></h1>
733 <li>Have pg_ctl look at PGHOST in case it is a socket directory?
734 </li><li>Allow pg_ctl to work properly with configuration files located outside
736 <p> pg_ctl can not read the pid file because it isn't located in the
737 config directory but in the PGDATA directory. The solution is to
738 allow pg_ctl to read and understand postgresql.conf to find the
739 data_directory value.
741 </li><li>Add a function like pg_get_indexdef() that report more detailed index
743 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2007-12/msg00166.php">http://archives.postgresql.org/pgsql-bugs/2007-12/msg00166.php</a>
747 <li>Have psql show current values for a sequence
748 </li><li>Move psql backslash database information into the backend, use
749 mnemonic commands? [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?psql">psql</a>]
750 <p> This would allow non-psql clients to pull the same information out
751 of the database as psql.
753 </li><li>Fix psql's \d commands more consistent
754 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php">http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php</a>
755 <a href="http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php">http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php</a>
757 </li><li>Consistently display privilege information for all objects in psql
758 </li><li>Add auto-expanded mode so expanded output is used if the row
759 length is wider than the screen width.
760 <p> Consider using auto-expanded mode for backslash commands like \df+.
762 </li><li>Prevent tab completion of SET TRANSACTION from querying the
763 database and therefore preventing the transaction isolation
764 level from being set.
765 <p> Currently SET <tab> causes a database lookup to check all
766 supported session variables. This query causes problems
767 because setting the transaction isolation level must be the
768 first statement of a transaction.
770 </li><li>Add a \set variable to control whether \s displays line numbers
771 <p> Another option is to add \# which lists line numbers, and
772 allows command execution.
774 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00255.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00255.php</a>
776 </li><li>Prevent escape string warnings when object names have
778 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00227.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00227.php</a>
780 </li><li>Have \d show foreign keys that reference a table's primary key
781 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-04/msg00424.php">http://archives.postgresql.org/pgsql-hackers/2007-04/msg00424.php</a>
783 </li><li>Have \d show child tables that inherit from the specified parent
784 </li><li>Have \l+ show database size, if permissions allow
785 <p> Ideally it will not generate an error for invalid permissions
788 </li><li>pg_dump / pg_restore
790 <li>%Add dumping of comments on index columns and composite type columns
791 </li><li>%Add full object name to the tag field. eg. for operators we need
792 '=(integer, integer)', instead of just '='.
793 </li><li>Add pg_dumpall custom format dumps?
794 </li><li>Allow selection of individual object(s) of all types, not just
796 </li><li>In a selective dump, allow dumping of an object and all its
798 </li><li>Add options like pg_restore -l and -L to pg_dump
799 </li><li>Stop dumping CASCADE on DROP TYPE commands in clean mode
800 </li><li>Allow pg_dump --clean to drop roles that own objects or have
802 </li><li>Change pg_dump so that a comment on the dumped database is
803 applied to the loaded database, even if the database has a
804 different name. This will require new backend syntax, perhaps
805 COMMENT ON CURRENT DATABASE.
806 </li><li>Remove unnecessary function pointer abstractions in pg_dump source
808 </li><li>Allow pg_dump to utilize multiple CPUs and I/O channels by dumping
809 multiple objects simultaneously
810 <p> The difficulty with this is getting multiple dump processes to
811 produce a single dump output file. It also would require
812 several sessions to share the same snapshot.
813 <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg00205.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg00205.php</a>
815 </li><li>Allow pg_restore to utilize multiple CPUs and I/O channels by
816 restoring multiple objects simultaneously
817 <p> This might require a pg_restore flag to indicate how many
818 simultaneous operations should be performed. Only pg_dump's
819 -Fc format has the necessary dependency information.
820 <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg00963.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg00963.php</a>
822 </li><li>To better utilize resources, allow pg_restore to check foreign
823 keys simultaneously, where possible
824 </li><li>Allow pg_restore to create all indexes of a table
825 concurrently, via a single heap scan
826 <p> This requires a pg_dump -Fc file because that format contains
827 the required dependency information.
828 <a href="http://archives.postgresql.org/pgsql-general/2007-05/msg01274.php">http://archives.postgresql.org/pgsql-general/2007-05/msg01274.php</a>
830 </li><li>Allow pg_restore to load different parts of the COPY data
836 <p> Document differences between ecpg and the SQL standard and
837 information about the Informix-compatibility module.
839 </li><li>Solve cardinality > 1 for input descriptors / variables?
840 </li><li>Add a semantic check level, e.g. check if a table really exists
841 </li><li>fix handling of DB attributes that are arrays
842 </li><li>Use backend PREPARE/EXECUTE facility for ecpg where possible
843 </li><li>Implement SQLDA
844 </li><li>Fix nested C comments
845 </li><li>%sqlwarn[<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?6">6</a>] should be 'W' if the PRECISION or SCALE value specified
846 </li><li>Make SET CONNECTION thread-aware, non-standard?
847 </li><li>Allow multidimensional arrays
848 </li><li>Add internationalized message strings
849 </li><li>Implement COPY FROM STDIN
853 <li>Add PQescapeIdentifierConn()
854 </li><li>Prevent PQfnumber() from lowercasing unquoted the column name
855 <p> PQfnumber() should never have been doing lowercasing, but
856 historically it has so we need a way to prevent it
858 </li><li>Allow statement results to be automatically batched to the client
859 <p> Currently all statement results are transferred to the libpq
860 client before libpq makes the results available to the
861 application. This feature would allow the application to make
862 use of the first result rows while the rest are transferred, or
863 held on the server waiting for them to be requested by libpq.
864 One complexity is that a statement like SELECT 1/col could error
865 out mid-way through the result set.
867 </li><li>Consider disallowing multiple queries in PQexec() as an
868 additional barrier to SQL injection attacks
869 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg00184.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg00184.php</a>
871 </li><li>Add PQexecf() that allows complex parameter substitution
872 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg01803.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg01803.php</a>
874 </li><li>Add SQLSTATE severity to PGconn return status
875 <p> <a href="http://archives.postgresql.org/pgsql-interfaces/2007-11/msg00015.php">http://archives.postgresql.org/pgsql-interfaces/2007-11/msg00015.php</a>
879 <h1><a name="section_11">Triggers</a></h1>
882 <li>Add deferred trigger queue file
883 <p> Right now all deferred trigger information is stored in backend
884 memory. This could exhaust memory for very large trigger queues.
885 This item involves dumping large queues into files.
887 </li><li>Allow triggers to be disabled in only the current session.
888 <p> This is currently possible by starting a multi-statement transaction,
889 modifying the system tables, performing the desired SQL, restoring the
890 system tables, and committing the transaction. ALTER TABLE ...
891 TRIGGER requires a table lock so it is not ideal for this usage.
893 </li><li>With disabled triggers, allow pg_dump to use ALTER TABLE ADD FOREIGN KEY
894 <p> If the dump is known to be valid, allow foreign keys to be added
895 without revalidating the data.
897 </li><li>Allow statement-level triggers to access modified rows
898 </li><li>Support triggers on columns
899 <p> <a href="http://archives.postgresql.org/pgsql-patches/2005-07/msg00107.php">http://archives.postgresql.org/pgsql-patches/2005-07/msg00107.php</a>
901 </li><li>Allow AFTER triggers on system tables
902 <p> System tables are modified in many places in the backend without going
903 through the executor and therefore not causing triggers to fire. To
904 complete this item, the functions that modify system tables will have
907 </li><li>Tighten trigger permission checks
908 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00564.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00564.php</a>
910 </li><li>Allow BEFORE INSERT triggers on views
911 <p> <a href="http://archives.postgresql.org/pgsql-general/2007-02/msg01466.php">http://archives.postgresql.org/pgsql-general/2007-02/msg01466.php</a>
913 </li><li>Add ability to trigger on TRUNCATE
914 <p> <a href="http://archives.postgresql.org/pgsql-sql/2008-01/msg00050.php">http://archives.postgresql.org/pgsql-sql/2008-01/msg00050.php</a>
917 <h1><a name="section_12">Indexes</a></h1>
920 <li>Add UNIQUE capability to non-btree indexes
921 </li><li>Prevent index uniqueness checks when UPDATE does not modify the column
922 <p> Uniqueness (index) checks are done when updating a column even if the
923 column is not modified by the UPDATE.
925 </li><li>Allow the creation of on-disk bitmap indexes which can be quickly
926 combined with other bitmap indexes
927 <p> Such indexes could be more compact if there are only a few distinct values.
928 Such indexes can also be compressed. Keeping such indexes updated can be
931 <p> <a href="http://archives.postgresql.org/pgsql-patches/2005-07/msg00512.php">http://archives.postgresql.org/pgsql-patches/2005-07/msg00512.php</a>
932 <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg01107.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg01107.php</a>
934 </li><li>Allow accurate statistics to be collected on indexes with more than
935 one column or expression indexes, perhaps using per-index statistics
936 <p> <a href="http://archives.postgresql.org/pgsql-performance/2006-10/msg00222.php">http://archives.postgresql.org/pgsql-performance/2006-10/msg00222.php</a>
937 <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg01131.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg01131.php</a>
939 </li><li>Consider compressing indexes by storing key values duplicated in
940 several rows as a single index entry
941 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00341.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00341.php</a>
942 <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg01264.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg01264.php</a>
943 <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg00465.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg00465.php</a>
944 <a href="http://archives.postgresql.org/pgsql-patches/2007-03/msg00163.php">http://archives.postgresql.org/pgsql-patches/2007-03/msg00163.php</a>
946 </li><li>Add REINDEX CONCURRENTLY, like CREATE INDEX CONCURRENTLY
947 <p> This is difficult because you must upgrade to an exclusive table lock
948 to replace the existing index file. CREATE INDEX CONCURRENTLY does not
949 have this complication. This would allow index compaction without
952 </li><li>Allow multiple indexes to be created concurrently, ideally via a
953 single heap scan, and have pg_restore use it
956 <li>Allow inherited tables to inherit indexes, UNIQUE constraints,
957 and primary/foreign keys
958 </li><li>Honor UNIQUE INDEX on base column in INSERTs/UPDATEs
959 on inherited table, e.g. INSERT INTO inherit_table
960 (unique_index_col) VALUES (dup) should fail
961 <p> The main difficulty with this item is the problem of
962 creating an index that can span multiple tables.
964 </li><li>Allow SELECT ... FOR UPDATE on inherited tables
965 </li><li>Require all CHECK constraints to be inherited
966 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2007-04/msg00026.php">http://archives.postgresql.org/pgsql-bugs/2007-04/msg00026.php</a>
971 <li>Add more GIST index support for geometric data types
972 </li><li>Allow GIST indexes to create certain complex index types, like
973 digital trees (see Aoki)
977 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-09/msg00051.php">http://archives.postgresql.org/pgsql-hackers/2007-09/msg00051.php</a>
980 <li>Pack hash index buckets onto disk pages more efficiently
981 <p> Currently only one hash bucket can be stored on a page. Ideally
982 several hash buckets could be stored on a single page and greater
983 granularity used for the hash algorithm.
985 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2004-06/msg00168.php">http://archives.postgresql.org/pgsql-hackers/2004-06/msg00168.php</a>
987 </li><li>Consider sorting hash buckets so entries can be found using a
988 binary search, rather than a linear scan
989 </li><li>In hash indexes, consider storing the hash value with or instead
991 </li><li>Add WAL logging for crash recovery
992 </li><li>Allow multi-column hash indexes
993 </li><li>During index creation, pre-sort the tuples to improve build speed
994 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg01199.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg01199.php</a>
997 <h1><a name="section_13">Fsync</a></h1>
1000 <li>Determine optimal fdatasync/fsync, O_SYNC/O_DSYNC options
1001 <p> Ideally this requires a separate test program that can be run
1002 at initdb time or optionally later. Consider O_SYNC when
1005 </li><li>Add program to test if fsync has a delay compared to non-fsync
1007 <h1><a name="section_14">Cache Usage</a></h1>
1010 <li>Speed up COUNT(*)
1011 <p> We could use a fixed row count and a +/- count to follow MVCC
1012 visibility rules, or a single cached value could be used and
1013 invalidated if anyone modifies the table. Another idea is to
1014 get a count directly from a unique index, but for this to be
1015 faster than a sequential scan it must avoid access to the heap
1016 to obtain tuple visibility information.
1018 </li><li>Provide a way to calculate an "estimated COUNT(*)"
1019 <p> Perhaps by using the optimizer's cardinality estimates or random
1022 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-11/msg00943.php">http://archives.postgresql.org/pgsql-hackers/2005-11/msg00943.php</a>
1024 </li><li>Allow data to be pulled directly from indexes
1025 <p> Currently indexes do not have enough tuple visibility information
1026 to allow data to be pulled from the index without also accessing
1027 the heap. One way to allow this is to set a bit on index tuples
1028 to indicate if a tuple is currently visible to all transactions
1029 when the first valid heap lookup happens. This bit would have to
1030 be cleared when a heap tuple is expired.
1032 <p> Another idea is to maintain a bitmap of heap pages where all rows
1033 are visible to all backends, and allow index lookups to reference
1034 that bitmap to avoid heap lookups, perhaps the same bitmap we might
1035 add someday to determine which heap pages need vacuuming. Frequently
1036 accessed bitmaps would have to be stored in shared memory. One 8k
1037 page of bitmaps could track 512MB of heap pages.
1039 <p> A third idea would be for a heap scan to check if all rows are visible
1040 and if so set a per-table flag which can be checked by index scans.
1041 Any change to the table would have to clear the flag. To detect
1042 changes during the heap scan a counter could be set at the start and
1043 checked at the end --- if it is the same, the table has not been
1044 modified --- any table change would increment the counter.
1046 </li><li>Consider automatic caching of statements at various levels:
1048 <li>Parsed query tree
1049 </li><li>Query execute plan
1050 </li><li>Query results
1052 </li><li>Consider increasing internal areas when shared buffers is increased
1053 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2005-10/msg01419.php">http://archives.postgresql.org/pgsql-hackers/2005-10/msg01419.php</a>
1055 </li><li>Consider decreasing the amount of memory used by PrivateRefCount
1056 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-11/msg00797.php">http://archives.postgresql.org/pgsql-hackers/2006-11/msg00797.php</a>
1057 <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg00752.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg00752.php</a>
1059 </li><li>Consider allowing higher priority queries to have referenced buffer
1060 cache pages stay in memory longer
1061 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg00562.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg00562.php</a>
1064 <h1><a name="section_15">Vacuum</a></h1>
1067 <li>Improve speed with indexes
1068 <p> For large table adjustments during VACUUM FULL, it is faster to cluster
1069 or reindex rather than update the index. Also, index updates can bloat
1072 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg00024.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg00024.php</a>
1073 <a href="http://archives.postgresql.org/pgsql-performance/2007-05/msg00296.php">http://archives.postgresql.org/pgsql-performance/2007-05/msg00296.php</a>
1075 </li><li>Auto-fill the free space map by scanning the buffer cache or by
1076 checking pages written by the background writer
1077 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-02/msg01125.php">http://archives.postgresql.org/pgsql-hackers/2006-02/msg01125.php</a>
1078 <a href="http://archives.postgresql.org/pgsql-hackers/2006-03/msg00011.php">http://archives.postgresql.org/pgsql-hackers/2006-03/msg00011.php</a>
1080 </li><li>Create a bitmap of pages that need vacuuming
1081 <p> Instead of sequentially scanning the entire table, have the background
1082 writer or some other process record pages that have expired rows, then
1083 VACUUM can look at just those pages rather than the entire table. In
1084 the event of a system crash, the bitmap would probably be invalidated.
1085 One complexity is that index entries still have to be vacuumed, and
1086 doing this without an index scan (by using the heap values to find the
1087 index entry) might be slow and unreliable, especially for user-defined
1090 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg01188.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg01188.php</a>
1091 <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg00121.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg00121.php</a>
1093 </li><li>Allow FSM to return free space toward the beginning of the heap file,
1094 in hopes that empty pages at the end can be truncated by VACUUM
1095 </li><li>Allow FSM page return free space based on table clustering, to assist
1096 in maintaining clustering?
1097 </li><li>Improve dead row detection during multi-statement transactions usage
1098 <p> <a href="http://archives.postgresql.org/pgsql-patches/2007-03/msg00358.php">http://archives.postgresql.org/pgsql-patches/2007-03/msg00358.php</a>
1100 </li><li>Auto-vacuum
1102 <li>%Issue log message to suggest VACUUM FULL if a table is nearly
1104 </li><li>Improve control of auto-vacuum
1105 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00876.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00876.php</a>
1107 </li><li>Prevent long-lived temporary tables from causing frozen-xid
1108 advancement starvation
1109 <p> The problem is that autovacuum cannot vacuum them to set frozen xids;
1110 only the session that created them can do that.
1111 <a href="http://archives.postgresql.org/pgsql-general/2007-06/msg01645.php">http://archives.postgresql.org/pgsql-general/2007-06/msg01645.php</a>
1113 </li><li>Store per-table autovacuum settings in pg_class.reloptions.
1114 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg01440.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg01440.php</a>
1115 <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00724.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00724.php</a>
1117 </li><li>Prevent autovacuum from running if an old transaction is still
1118 running from the last vacuum
1119 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg00899.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg00899.php</a>
1123 <h1><a name="section_16">Locking</a></h1>
1126 <li>Fix priority ordering of read and write light-weight locks (Neil)
1127 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2004-11/msg00893.php">http://archives.postgresql.org/pgsql-hackers/2004-11/msg00893.php</a>
1128 <a href="http://archives.postgresql.org/pgsql-hackers/2004-11/msg00905.php">http://archives.postgresql.org/pgsql-hackers/2004-11/msg00905.php</a>
1130 </li><li>Fix problem when multiple subtransactions of the same outer transaction
1131 hold different types of locks, and one subtransaction aborts
1132 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-11/msg01011.php">http://archives.postgresql.org/pgsql-hackers/2006-11/msg01011.php</a>
1133 <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg00001.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg00001.php</a>
1134 <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg00435.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg00435.php</a>
1136 </li><li>Allow UPDATEs on only non-referential integrity columns not to conflict
1137 with referential integrity locks
1138 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg00073.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg00073.php</a>
1140 </li><li>Add idle_in_transaction_timeout GUC so locks are not held for long
1142 </li><li>Improve deadlock detection when a page cleaning lock conflicts
1143 with a shared buffer that is pinned
1144 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2008-01/msg00138.php">http://archives.postgresql.org/pgsql-bugs/2008-01/msg00138.php</a>
1145 <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00873.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00873.php</a>
1146 <a href="http://archives.postgresql.org/pgsql-committers/2008-01/msg00365.php">http://archives.postgresql.org/pgsql-committers/2008-01/msg00365.php</a>
1149 <h1><a name="section_17">Startup Time Improvements</a></h1>
1152 <li>Experiment with multi-threaded backend for backend creation [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?thread">thread</a>]
1153 <p> This would prevent the overhead associated with process creation. Most
1154 operating systems have trivial process creation time compared to
1155 database startup overhead, but a few operating systems (Win32,
1156 Solaris) might benefit from threading. Also explore the idea of
1157 a single session using multiple threads to execute a statement faster.
1160 <h1><a name="section_18">Write-Ahead Log</a></h1>
1163 <li>Eliminate need to write full pages to WAL before page modification [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?wal">wal</a>]
1164 <p> Currently, to protect against partial disk page writes, we write
1165 full page images to WAL before they are modified so we can correct any
1166 partial page writes during recovery. These pages can also be
1167 eliminated from point-in-time archive files.
1170 <li>When off, write CRC to WAL and check file system blocks
1172 <p> If CRC check fails during recovery, remember the page in case
1173 a later CRC for that page properly matches.
1175 </li><li>Write full pages during file system write and not when
1176 the page is modified in the buffer cache
1177 <p> This allows most full page writes to happen in the background
1178 writer. It might cause problems for applying WAL on recovery
1179 into a partially-written page, but later the full page will be
1183 </li><li>Allow WAL traffic to be streamed to another server for stand-by
1185 </li><li>Reduce WAL traffic so only modified values are written rather than
1187 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-03/msg01589.php">http://archives.postgresql.org/pgsql-hackers/2007-03/msg01589.php</a>
1189 </li><li>Allow WAL information to recover corrupted pg_controldata
1190 <p> <a href="http://archives.postgresql.org/pgsql-patches/2006-06/msg00025.php">http://archives.postgresql.org/pgsql-patches/2006-06/msg00025.php</a>
1192 </li><li>Find a way to reduce rotational delay when repeatedly writing
1194 <p> Currently fsync of WAL requires the disk platter to perform a full
1195 rotation to fsync again. One idea is to write the WAL to different
1196 offsets that might reduce the rotational delay.
1198 </li><li>Allow WAL logging to be turned off for a table, but the table
1199 might be dropped or truncated during crash recovery [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?walcontrol">walcontrol</a>]
1200 <p> Allow tables to bypass WAL writes and just fsync() dirty pages on
1201 commit. This should be implemented using ALTER TABLE, e.g. ALTER
1202 TABLE PERSISTENCE [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo? DROP | TRUNCATE | DEFAULT "> DROP | TRUNCATE | DEFAULT </a>]. Tables using
1203 non-default logging should not use referential integrity with
1204 default-logging tables. A table without dirty buffers during a
1205 crash could perhaps avoid the drop/truncate.
1207 </li><li>Allow WAL logging to be turned off for a table, but the table would
1208 avoid being truncated/dropped [<a href="http://momjian.postgresql.org/cgi-bin/pgtodo?walcontrol">walcontrol</a>]
1209 <p> To do this, only a single writer can modify the table, and writes
1210 must happen only on new pages so the new pages can be removed during
1211 crash recovery. Readers can continue accessing the table. Such
1212 tables probably cannot have indexes. One complexity is the handling
1213 of indexes on TOAST tables.
1215 </li><li>Speed WAL recovery by allowing more than one page to be prefetched
1216 <p> This involves having a separate process that can be told which pages
1217 the recovery process will need in the near future.
1218 <a href="http://archives.postgresql.org/pgsql-hackers/2008-02/msg01279.php">http://archives.postgresql.org/pgsql-hackers/2008-02/msg01279.php</a>
1221 <h1><a name="section_19">Optimizer / Executor</a></h1>
1224 <li>Improve selectivity functions for geometric operators
1225 </li><li>Precompile SQL functions to avoid overhead
1226 </li><li>Create utility to compute accurate random_page_cost value
1227 </li><li>Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
1228 </li><li>Have EXPLAIN ANALYZE issue NOTICE messages when the estimated and
1229 actual row counts differ by a specified percentage
1230 </li><li>Consider using hash buckets to do DISTINCT, rather than sorting
1231 <p> This would be beneficial when there are few distinct values. This is
1232 already used by GROUP BY.
1234 </li><li>Log statements where the optimizer row estimates were dramatically
1235 different from the number of rows actually found?
1236 </li><li>Consider compressed annealing to search for query plans
1237 <p> This might replace GEQO, <a href="http://sixdemonbag.org/Djinni">http://sixdemonbag.org/Djinni</a>.
1239 </li><li>Improve merge join performance by allowing mark/restore of
1241 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-01/msg00096.php">http://archives.postgresql.org/pgsql-hackers/2007-01/msg00096.php</a>
1244 <h1><a name="section_20">Miscellaneous Performance</a></h1>
1247 <li>Do async I/O for faster random read-ahead of data
1248 <p> Async I/O allows multiple I/O requests to be sent to the disk with
1249 results coming back asynchronously.
1251 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-10/msg00820.php">http://archives.postgresql.org/pgsql-hackers/2006-10/msg00820.php</a>
1252 <a href="http://archives.postgresql.org/pgsql-hackers/2007-12/msg00027.php">http://archives.postgresql.org/pgsql-hackers/2007-12/msg00027.php</a>
1254 </li><li>Use mmap() rather than SYSV shared memory or to write WAL files?
1255 <p> This would remove the requirement for SYSV SHM but would introduce
1256 portability issues. Anonymous mmap (or mmap to /dev/zero) is required
1257 to prevent I/O overhead.
1259 </li><li>Consider mmap()'ing files into a backend?
1260 <p> Doing I/O to large tables would consume a lot of address space or
1261 require frequent mapping/unmapping. Extending the file also causes
1262 mapping problems that might require mapping only individual pages,
1263 leading to thousands of mappings. Another problem is that there is no
1264 way to <u>prevent</u> I/O to disk from the dirty shared buffers so changes
1265 could hit disk before WAL is written.
1267 </li><li>Add a script to ask system configuration questions and tune postgresql.conf
1268 </li><li>Consider ways of storing rows more compactly on disk
1270 <li>Reduce the row header size?
1271 </li><li>Consider reducing on-disk varlena length from four bytes to
1272 two because a heap row cannot be more than 64k in length
1274 </li><li>Consider increasing NUM_CLOG_BUFFERS
1275 </li><li>Consider having the background writer update the transaction status
1276 hint bits before writing out the page
1277 <p> Implementing this requires the background writer to have access to system
1278 catalogs and the transaction status log.
1280 </li><li>Allow user configuration of TOAST thresholds
1281 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-02/msg00213.php">http://archives.postgresql.org/pgsql-hackers/2007-02/msg00213.php</a>
1283 </li><li>Allow configuration of backend priorities via the operating system
1284 <p> Though backend priorities make priority inversion during lock
1285 waits possible, research shows that this is not a huge problem.
1287 <p> <a href="http://archives.postgresql.org/pgsql-general/2007-02/msg00493.php">http://archives.postgresql.org/pgsql-general/2007-02/msg00493.php</a>
1289 </li><li>Experiment with multi-threaded backend better resource utilization
1290 <p> This would allow a single query to make use of multiple CPU's or
1291 multiple I/O channels simultaneously. One idea is to create a
1292 background reader that can pre-fetch sequential and index scan
1293 pages needed by other backends. This could be expanded to allow
1294 concurrent reads from multiple devices in a partitioned table.
1296 </li><li>Consider increasing the minimum allowed number of shared buffers
1297 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2008-02/msg00157.php">http://archives.postgresql.org/pgsql-bugs/2008-02/msg00157.php</a>
1300 <h1><a name="section_21">Source Code</a></h1>
1303 <li>Add use of 'const' for variables in source tree
1304 </li><li>Move some things from contrib into main tree
1305 </li><li>%Remove warnings created by -Wcast-align
1306 </li><li>Move platform-specific ps status display info from ps_status.c to ports
1307 </li><li>Add optional CRC checksum to heap and index pages
1308 </li><li>Improve documentation to build only interfaces (Marc)
1309 </li><li>Remove or relicense modules that are not under the BSD license, if possible
1310 </li><li>Acquire lock on a relation before building a relcache entry for it
1311 </li><li>Allow cross-compiling by generating the zic database on the target system
1312 </li><li>Improve NLS maintenance of libpgport messages linked onto applications
1313 </li><li>Clean up casting in contrib/isn
1314 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-11/msg00245.php">http://archives.postgresql.org/pgsql-hackers/2006-11/msg00245.php</a>
1316 </li><li>Use UTF8 encoding for NLS messages so all server encodings can
1318 </li><li>Update Bonjour to work with newer cross-platform SDK
1319 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-09/msg02238.php">http://archives.postgresql.org/pgsql-hackers/2006-09/msg02238.php</a>
1320 <a href="http://archives.postgresql.org/pgsql-patches/2006-10/msg00048.php">http://archives.postgresql.org/pgsql-patches/2006-10/msg00048.php</a>
1322 </li><li>Consider detoasting keys before sorting
1323 </li><li>Consider GnuTLS if OpenSSL license becomes a problem
1324 <p> <a href="http://archives.postgresql.org/pgsql-patches/2006-05/msg00040.php">http://archives.postgresql.org/pgsql-patches/2006-05/msg00040.php</a>
1325 <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg01213.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg01213.php</a>
1327 </li><li>Consider changing documentation format from SGML to XML
1328 <p> <a href="http://archives.postgresql.org/pgsql-docs/2006-12/msg00152.php">http://archives.postgresql.org/pgsql-docs/2006-12/msg00152.php</a>
1330 </li><li>Consider making NAMEDATALEN more configurable in future releases
1331 </li><li>Update our code to handle 64-bit timezone files to match the zic
1332 source code, which now uses them
1333 </li><li>Have configure choose integer datetimes by default
1334 <p> <a href="http://archives.postgresql.org/pgsql-patches/2007-05/msg00046.php">http://archives.postgresql.org/pgsql-patches/2007-05/msg00046.php</a>
1336 </li><li>Support scoped IPv6 addresses
1337 <p> <a href="http://archives.postgresql.org/pgsql-bugs/2007-05/msg00111.php">http://archives.postgresql.org/pgsql-bugs/2007-05/msg00111.php</a>
1339 </li><li>Consider allowing 64-bit integers and floats to be passed by value on
1341 <p> Also change 32-bit floats (float4) to be passed by value at the same
1346 <li>Remove configure.in check for link failure when cause is found
1347 </li><li>Remove readdir() errno patch when runtime/mingwex/dirent.c rev
1349 </li><li>Remove psql newline patch when we find out why mingw outputs an
1351 </li><li>Allow psql to use readline once non-US code pages work with
1353 </li><li>Fix problem with shared memory on the Win32 Terminal Server
1354 </li><li>Improve signal handling
1355 <p> <a href="http://archives.postgresql.org/pgsql-patches/2005-06/msg00027.php">http://archives.postgresql.org/pgsql-patches/2005-06/msg00027.php</a>
1358 </li><li>Wire Protocol Changes
1360 <li>Allow dynamic character set handling
1361 </li><li>Add decoded type, length, precision
1362 </li><li>Use compression?
1363 </li><li>Update clients to use data types, typmod, schema.table.column names
1364 of result sets using new statement protocol
1367 <h1><a name="section_22">Exotic Features</a></h1>
1370 <li>Add pre-parsing phase that converts non-ISO syntax to supported
1372 <p> This could allow SQL written for other databases to run without
1375 </li><li>Allow plug-in modules to emulate features from other databases
1376 </li><li>Add features of Oracle-style packages (Pavel)
1377 <p> A package would be a schema with session-local variables,
1378 public/private functions, and initialization functions. It
1379 is also possible to implement these capabilities
1380 in any schema and not use a separate "packages"
1383 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-08/msg00384.php">http://archives.postgresql.org/pgsql-hackers/2006-08/msg00384.php</a>
1385 </li><li>Consider allowing control of upper/lower case folding of unquoted
1387 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2004-04/msg00818.php">http://archives.postgresql.org/pgsql-hackers/2004-04/msg00818.php</a>
1388 <a href="http://archives.postgresql.org/pgsql-hackers/2006-10/msg01527.php">http://archives.postgresql.org/pgsql-hackers/2006-10/msg01527.php</a>
1390 </li><li>Add autonomous transactions
1391 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00893.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00893.php</a>
1394 <h1><a name="section_23">Features We Do <u>Not</u> Want</a></h1>
1397 <li>All backends running as threads in a single process (not wanted)
1398 <p> This eliminates the process protection we get from the current setup.
1399 Thread creation is usually the same overhead as process creation on
1400 modern systems, so it seems unwise to use a pure threaded model.
1402 </li><li>Optimizer hints (not wanted)
1403 <p> Optimizer hints are used to work around problems in the optimizer. We
1404 would rather have the problems reported and fixed.
1406 <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-08/msg00506.php">http://archives.postgresql.org/pgsql-hackers/2006-08/msg00506.php</a>
1407 <a href="http://archives.postgresql.org/pgsql-hackers/2006-10/msg00517.php">http://archives.postgresql.org/pgsql-hackers/2006-10/msg00517.php</a>
1408 <a href="http://archives.postgresql.org/pgsql-hackers/2006-10/msg00663.php">http://archives.postgresql.org/pgsql-hackers/2006-10/msg00663.php</a>
1410 <p> Because we support postfix operators, it isn't possible to make AS
1411 optional and continue to use bison.
1412 <a href="http://archives.postgresql.org/pgsql-hackers/2003-04/msg00436.php">http://archives.postgresql.org/pgsql-hackers/2003-04/msg00436.php</a>
1414 <p> <a href="http://archives.postgresql.org/pgsql-sql/2006-08/msg00164.php">http://archives.postgresql.org/pgsql-sql/2006-08/msg00164.php</a>
1416 </li><li>Embedded server (not wanted)
1417 <p> While PostgreSQL clients runs fine in limited-resource environments, the
1418 server requires multiple processes and a stable pool of resources to
1419 run reliabily and efficiently. Stripping down the PostgreSQL server
1420 to run in the same process address space as the client application
1421 would add too much complexity and failure cases.</p>