PostgreSQL TODO List
====================
-Last updated: Mon Nov 26 18:31:05 EST 2007
+Last updated: Fri Dec 7 12:52:05 EST 2007
The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html.
* Configuration files
- o -Allow commenting of variables in postgresql.conf to restore them
- to defaults
o Allow pg_hba.conf to specify host names along with IP addresses
Host name lookup could occur when the postmaster reads the
requires a tool that will call that function and connect to each
database to find the objects in each database for that tablespace.
- o -Add a GUC variable to control the tablespace for temporary objects
- and sort files
o Allow WAL replay of CREATE TABLESPACE to work when the directory
structure on the recovery computer is different from the original
http://archives.postgresql.org/pgsql-hackers/2006-12/msg00497.php
-Monitoring
-==========
-
-* -Allow server log information to be output as CSV format
-* -Add ability to monitor the use of temporary sort files
Data Types
* Fix data types where equality comparison isn't intuitive, e.g. box
* Allow user-defined types to specify a type modifier at table creation
time
-* -Allow user-defined types to accept 'typmod' parameters
-
- http://archives.postgresql.org/pgsql-hackers/2005-08/msg01142.php
- http://archives.postgresql.org/pgsql-hackers/2005-09/msg00012.php
- http://archives.postgresql.org/pgsql-hackers/2006-08/msg00149.php
-
* Add support for public SYNONYMs
http://archives.postgresql.org/pgsql-hackers/2006-03/msg00519.php
http://archives.postgresql.org/pgsql-hackers/2006-05/msg00072.php
http://archives.postgresql.org/pgsql-hackers/2006-09/msg01681.php
-* -Add Globally/Universally Unique Identifier (GUID/UUID)
-
- http://archives.postgresql.org/pgsql-patches/2006-09/msg00209.php
- http://archives.postgresql.org/pgsql-general/2007-01/msg00853.php
-
* Add support for SQL-standard GENERATED/IDENTITY columns
http://archives.postgresql.org/pgsql-hackers/2006-07/msg00543.php
http://archives.postgresql.org/pgsql-hackers/2007-05/msg00344.php
http://archives.postgresql.org/pgsql-patches/2007-05/msg00076.php
-* -Support a data type with specific enumerated values (ENUM)
* Improve XML support
http://developer.postgresql.org/index.php/XML_Support
http://archives.postgresql.org/pgsql-patches/2007-05/msg00114.php
- o -Add support for arrays of complex types
o Allow single-byte header storage for array elements
* MONEY data type
- o -Make 64-bit version of the MONEY data type
* Add locale-aware MONEY type, and support multiple currencies
http://archives.postgresql.org/pgsql-general/2005-08/msg01432.php
o to_char(INTERVAL '43 hours 20 minutes', 'WK:DD:HR:MI') => 0:1:19:20
o to_char(INTERVAL '3 years 5 months','MM') => 41
-* -Add ISO day of week format 'ID' to to_char() where Monday = 1
-* -Add a field 'isoyear' to extract(), based on the ISO week
* Implement inlining of set-returning functions defined in SQL
* Allow SQL-language functions to return results from RETURNING queries
* Add NOVICE output level for helpful messages like automatic sequence/index
creation
-* -Add RESET SESSION command to reset all session state
* Add GUC to issue notice about statements that use unjoined tables
* Allow EXPLAIN to identify tables that were skipped because of
constraint_exclusion
* CLUSTER
- o -Make CLUSTER preserve recently-dead tuples per MVCC requirements
o Automatically maintain clustering on a table
This might require some background daemon to maintain clustering
o %Add VERBOSE option to report tables as they are processed,
like VACUUM VERBOSE
- o -Add more logical syntax CLUSTER table USING index;
- support current syntax for backward compatibility
* COPY
* CURSOR
- o -Allow UPDATE/DELETE WHERE CURRENT OF cursor
o Prevent DROP TABLE from dropping a row referenced by its own open
cursor?
http://archives.postgresql.org/pgsql-patches/2006-06/msg00031.php
o Add single-step debugging of functions
- o -Add support for MOVE cursors
o Add support for SCROLL cursors
o Add support for WITH HOLD cursors
o Allow RETURN to return row or record functions
http://archives.postgresql.org/pgsql-patches/2006-02/msg00288.php
- o -Allow PL/PythonU to return boolean rather than 1/0
o Allow data to be passed in native language formats, rather
than only text
http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php
http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php
- o -Allow psql \pset boolean variables to set to fixed values, rather
- than toggle
o Consistently display privilege information for all objects in psql
o Add auto-expanded mode so expanded output is used if the row
length is wider than the screen width.
o Stop dumping CASCADE on DROP TYPE commands in clean mode
o Allow pg_dump --clean to drop roles that own objects or have
privileges
- o -Add -f to pg_dumpall
o Change pg_dump so that a comment on the dumped database is
applied to the loaded database, even if the database has a
different name. This will require new backend syntax, perhaps
-Dependency Checking
-===================
-
-* -Flush cached query plans when the dependent objects change or
- when new ANALYZE statistics are available
-* -Track dependencies in function bodies and recompile/invalidate
-* -Invalidate prepared queries, like INSERT, when the table definition
- is altered
-
Indexes
=======
http://archives.postgresql.org/pgsql-patches/2005-07/msg00512.php
http://archives.postgresql.org/pgsql-hackers/2006-12/msg01107.php
-* -Allow use of indexes to search for NULLs
* Allow accurate statistics to be collected on indexes with more than
one column or expression indexes, perhaps using per-index statistics
http://archives.postgresql.org/pgsql-performance/2006-10/msg00222.php
http://archives.postgresql.org/pgsql-hackers/2007-03/msg01131.php
-* -Allow the creation of indexes with mixed ascending/descending
- specifiers
* Consider compressing indexes by storing key values duplicated in
several rows as a single index entry
* %Add an option to sync() before fsync()'ing checkpoint files
* Add program to test if fsync has a delay compared to non-fsync
-* -Reduce checkpoint performance degredation by forcing data to disk
- more evenly
Cache Usage
o Query execute plan
o Query results
-* -Allow sequential scans to take advantage of other concurrent
- sequential scans, also called "Synchronised Scanning"
* Consider increasing internal areas when shared buffers is increased
http://archives.postgresql.org/pgsql-hackers/2005-10/msg01419.php
in hopes that empty pages at the end can be truncated by VACUUM
* Allow FSM page return free space based on table clustering, to assist
in maintaining clustering?
-* -Consider shrinking expired tuples to just their headers
-* -Allow heap reuse of UPDATEd rows if no indexed columns are changed,
- and old and new versions are on the same heap page
* Improve dead row detection during multi-statement transactions usage
http://archives.postgresql.org/pgsql-patches/2007-03/msg00358.php
-* -Reduce XID consumption of read-only queries
* Prevent long-lived temporary tables from causing frozen-xid advancement
starvation
o %Issue log message to suggest VACUUM FULL if a table is nearly
empty?
o Consider logging activity either to the logs or a system view
- o -Turn on by default
- o -Allow multiple vacuums so large tables do not starve small
- tables
o Improve control of auto-vacuum
http://archives.postgresql.org/pgsql-hackers/2006-12/msg00876.php
http://archives.postgresql.org/pgsql-hackers/2007-03/msg01589.php
-* -Allow the pg_xlog directory location to be specified during initdb
- with a symlink back to the /data location
* Allow WAL information to recover corrupted pg_controldata
http://archives.postgresql.org/pgsql-patches/2006-06/msg00025.php
rotation to fsync again. One idea is to write the WAL to different
offsets that might reduce the rotational delay.
-* -Allow buffered WAL writes and fsync
* Allow WAL logging to be turned off for a table, but the table
might be dropped or truncated during crash recovery [walcontrol]
====================
* Improve selectivity functions for geometric operators
-* -Allow ORDER BY ... LIMIT # to select high/low value without sort or
- index using a sequential scan for highest/lowest values
* Precompile SQL functions to avoid overhead
* Create utility to compute accurate random_page_cost value
* Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
could hit disk before WAL is written.
* Add a script to ask system configuration questions and tune postgresql.conf
-* -Merge xmin/xmax/cmin/cmax back into three header fields
* Consider ways of storing rows more compactly on disk
- o -Support a smaller header for short variable-length fields
o Reduce the row header size?
o Consider reducing on-disk varlena length from four bytes to
two because a heap row cannot be more than 64k in length
http://archives.postgresql.org/pgsql-docs/2006-12/msg00152.php
-* -Move NAMEDATALEN from postgres_ext.h to pg_config_manual.h
* Consider making NAMEDATALEN more configurable in future releases
* Update our code to handle 64-bit timezone files to match the zic
source code, which now uses them
http://archives.postgresql.org/pgsql-patches/2007-05/msg00046.php
-* -Fix problem with excessive logging during SSL disconnection
-
- http://archives.postgresql.org/pgsql-bugs/2006-12/msg00122.php
- http://archives.postgresql.org/pgsql-bugs/2007-05/msg00065.php
-
* Support scoped IPv6 addresses
http://archives.postgresql.org/pgsql-bugs/2007-05/msg00111.php
http://archives.postgresql.org/pgsql-patches/2005-06/msg00027.php
- o -Add long file support for binary pg_dump output
* Wire Protocol Changes
-Last updated: Mon Nov 26 18:31:05 EST 2007
+Last updated: Fri Dec 7 12:52:05 EST 2007
The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html.
Configuration files
-
-Allow commenting of variables in postgresql.conf to restore them
- to defaults
-
Allow pg_hba.conf to specify host names along with IP addresses
+
Allow pg_hba.conf to specify host names along with IP addresses
Host name lookup could occur when the postmaster reads the
pg_hba.conf file, or when the backend starts. Another
solution would be to reverse lookup the connection IP and
requires a tool that will call that function and connect to each
database to find the objects in each database for that tablespace.
-
-Add a GUC variable to control the tablespace for temporary objects
- and sort files
Allow WAL replay of CREATE TABLESPACE to work when the directory
structure on the recovery computer is different from the original
Allow per-tablespace quotas
-
-
-Allow server log information to be output as CSV format
-
-Add ability to monitor the use of temporary sort files
-
Change NUMERIC to enforce the maximum precision
Fix data types where equality comparison isn't intuitive, e.g. box
Allow user-defined types to specify a type modifier at table creation
time
-
-Allow user-defined types to accept 'typmod' parameters
-
http://archives.postgresql.org/pgsql-hackers/2005-08/msg01142.php
-
http://archives.postgresql.org/pgsql-hackers/2005-09/msg00012.php-
http://archives.postgresql.org/pgsql-hackers/2006-08/msg00149.php-
Add support for public SYNONYMs
http://archives.postgresql.org/pgsql-hackers/2006-03/msg00519.php
Fix CREATE CAST on DOMAINs
http://archives.postgresql.org/pgsql-hackers/2006-05/msg00072.php
http://archives.postgresql.org/pgsql-hackers/2006-09/msg01681.php
-
-
-Add Globally/Universally Unique Identifier (GUID/UUID)
-
http://archives.postgresql.org/pgsql-patches/2006-09/msg00209.php
-
http://archives.postgresql.org/pgsql-general/2007-01/msg00853.php
Add support for SQL-standard GENERATED/IDENTITY columns
http://archives.postgresql.org/pgsql-hackers/2006-07/msg00543.php
http://archives.postgresql.org/pgsql-hackers/2007-05/msg00344.php
http://archives.postgresql.org/pgsql-patches/2007-05/msg00076.php
-
-Support a data type with specific enumerated values (ENUM)
Improve XML support
http://developer.postgresql.org/index.php/XML_Support
Add support for arrays of domains
http://archives.postgresql.org/pgsql-patches/2007-05/msg00114.php
-
-Add support for arrays of complex types
Allow single-byte header storage for array elements
Binary Data
MONEY data type
-
-Make 64-bit version of the MONEY data type
-
Add locale-aware MONEY type, and support multiple currencies
+
Add locale-aware MONEY type, and support multiple currencies
http://archives.postgresql.org/pgsql-general/2005-08/msg01432.php
http://archives.postgresql.org/pgsql-hackers/2007-03/msg01181.php
-
MONEY dumps in a locale-specific format making it difficult to
+
MONEY dumps in a locale-specific format making it difficult to
restore to a system with a different locale
-
Allow MONEY to be cast to/from other numeric data types
-
+
Allow MONEY to be cast to/from other numeric data types
Allow INET subnet tests using non-constants to be indexed
to_char(INTERVAL '43 hours 20 minutes', 'WK:DD:HR:MI') => 0:1:19:20
to_char(INTERVAL '3 years 5 months','MM') => 41
-
-Add ISO day of week format 'ID' to to_char() where Monday = 1
-
-Add a field 'isoyear' to extract(), based on the ISO week
Implement inlining of set-returning functions defined in SQL
Allow SQL-language functions to return results from RETURNING queries
http://archives.postgresql.org/pgsql-hackers/2006-10/msg00665.php
http://archives.postgresql.org/pgsql-patches/2007-08/msg00012.php
-
6">Multi-Language Support
+
5">Multi-Language Support
Add NCHAR (as distinguished from ordinary varchar),
http://archives.postgresql.org/pgsql-hackers/2007-03/msg00767.php
Automatically create rules on views so they are updateable, per SQL99
http://archives.postgresql.org/pgsql-hackers/2007-09/msg00577.php
Add CORRESPONDING BY to UNION/INTERSECT/EXCEPT
Add NOVICE output level for helpful messages like automatic sequence/index
creation
-
-Add RESET SESSION command to reset all session state
Add GUC to issue notice about statements that use unjoined tables
Allow EXPLAIN to identify tables that were skipped because of
constraint_exclusion
CLUSTER
-
-Make CLUSTER preserve recently-dead tuples per MVCC requirements
-
Automatically maintain clustering on a table
+
Automatically maintain clustering on a table
This might require some background daemon to maintain clustering
during periods of low usage. It might also require tables to be only
partially filled for easier reorganization. Another idea would
%Add VERBOSE option to report tables as they are processed,
like VACUUM VERBOSE
-
-Add more logical syntax CLUSTER table USING index;
- support current syntax for backward compatibility
COPY
CURSOR
-
-Allow UPDATE/DELETE WHERE CURRENT OF cursor
-
Prevent DROP TABLE from dropping a row referenced by its own open
+
Prevent DROP TABLE from dropping a row referenced by its own open
cursor?
INSERT
http://archives.postgresql.org/pgsql-patches/2006-06/msg00031.php
Add single-step debugging of functions
-
-Add support for MOVE cursors
Add support for SCROLL cursors
Add support for WITH HOLD cursors
Allow RETURN to return row or record functions
Add PL/PythonU tracebacks
http://archives.postgresql.org/pgsql-patches/2006-02/msg00288.php
-
-Allow PL/PythonU to return boolean rather than 1/0
Allow data to be passed in native language formats, rather
than only text
http://archives.postgresql.org/pgsql-hackers/2007-05/msg00289.php
Have pg_ctl look at PGHOST in case it is a socket directory?
http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php
http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php
-
-Allow psql \pset boolean variables to set to fixed values, rather
- than toggle
Consistently display privilege information for all objects in psql
Add auto-expanded mode so expanded output is used if the row
length is wider than the screen width.
Stop dumping CASCADE on DROP TYPE commands in clean mode
Allow pg_dump --clean to drop roles that own objects or have
privileges
-
-Add -f to pg_dumpall
Change pg_dump so that a comment on the dumped database is
applied to the loaded database, even if the database has a
different name. This will require new backend syntax, perhaps
Add deferred trigger queue file
http://archives.postgresql.org/pgsql-general/2007-02/msg01466.php
-
-
-Flush cached query plans when the dependent objects change or
- when new ANALYZE statistics are available
-
-Track dependencies in function bodies and recompile/invalidate
-
-Invalidate prepared queries, like INSERT, when the table definition
- is altered
-
Add UNIQUE capability to non-btree indexes
http://archives.postgresql.org/pgsql-patches/2005-07/msg00512.php
http://archives.postgresql.org/pgsql-hackers/2006-12/msg01107.php
-
-Allow use of indexes to search for NULLs
Allow accurate statistics to be collected on indexes with more than
one column or expression indexes, perhaps using per-index statistics
http://archives.postgresql.org/pgsql-performance/2006-10/msg00222.php
http://archives.postgresql.org/pgsql-hackers/2007-03/msg01131.php
-
-Allow the creation of indexes with mixed ascending/descending
- specifiers
Consider compressing indexes by storing key values duplicated in
several rows as a single index entry
This is difficult because it requires datatype-specific knowledge.
Improve commit_delay handling to reduce fsync()
%Add an option to sync() before fsync()'ing checkpoint files
Add program to test if fsync has a delay compared to non-fsync
-
-Reduce checkpoint performance degredation by forcing data to disk
- more evenly
Allow free-behind capability for large sequential scans to avoid
Query execute plan
Query results
-
-Allow sequential scans to take advantage of other concurrent
- sequential scans, also called "Synchronised Scanning"
Consider increasing internal areas when shared buffers is increased
http://archives.postgresql.org/pgsql-hackers/2005-10/msg01419.php
http://archives.postgresql.org/pgsql-hackers/2007-01/msg00752.php
Improve speed with indexes
in hopes that empty pages at the end can be truncated by VACUUM
Allow FSM page return free space based on table clustering, to assist
in maintaining clustering?
-
-Consider shrinking expired tuples to just their headers
-
-Allow heap reuse of UPDATEd rows if no indexed columns are changed,
- and old and new versions are on the same heap page
Improve dead row detection during multi-statement transactions usage
http://archives.postgresql.org/pgsql-patches/2007-03/msg00358.php
-
-Reduce XID consumption of read-only queries
Prevent long-lived temporary tables from causing frozen-xid advancement
starvation
%Issue log message to suggest VACUUM FULL if a table is nearly
empty?
Consider logging activity either to the logs or a system view
-
-Turn on by default
-
-Allow multiple vacuums so large tables do not starve small
- tables
Improve control of auto-vacuum
http://archives.postgresql.org/pgsql-hackers/2006-12/msg00876.php
Fix priority ordering of read and write light-weight locks (Neil)
Add idle_in_transaction_timeout GUC so locks are not held for long
periods of time
-
7">Startup Time Improvements
+
5">Startup Time Improvements
Experiment with multi-threaded backend for backend creation [thread]
existing backends is one of the difficulties with a backend approach.
Eliminate need to write full pages to WAL before page modification [wal]
entire rows
http://archives.postgresql.org/pgsql-hackers/2007-03/msg01589.php
-
-Allow the pg_xlog directory location to be specified during initdb
- with a symlink back to the /data location
Allow WAL information to recover corrupted pg_controldata
http://archives.postgresql.org/pgsql-patches/2006-06/msg00025.php
rotation to fsync again. One idea is to write the WAL to different
offsets that might reduce the rotational delay.
-
-Allow buffered WAL writes and fsync
Allow WAL logging to be turned off for a table, but the table
might be dropped or truncated during crash recovery [
walcontrol] Allow tables to bypass WAL writes and just fsync() dirty pages on
of indexes on TOAST tables.
Improve selectivity functions for geometric operators
-
-Allow ORDER BY ... LIMIT # to select high/low value without sort or
- index using a sequential scan for highest/lowest values
Precompile SQL functions to avoid overhead
Create utility to compute accurate random_page_cost value
Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
http://archives.postgresql.org/pgsql-hackers/2007-01/msg00096.php
-
20">Miscellaneous Performance
+
18">Miscellaneous Performance
Do async I/O for faster random read-ahead of data
could hit disk before WAL is written.
Add a script to ask system configuration questions and tune postgresql.conf
-
-Merge xmin/xmax/cmin/cmax back into three header fields
Consider ways of storing rows more compactly on disk
-
-Support a smaller header for short variable-length fields
-
Reduce the row header size?
+
Reduce the row header size?
Consider reducing on-disk varlena length from four bytes to
two because a heap row cannot be more than 64k in length
http://archives.postgresql.org/pgsql-hackers/2007-01/msg00752.php
Add use of 'const' for variables in source tree
Consider changing documentation format from SGML to XML
http://archives.postgresql.org/pgsql-docs/2006-12/msg00152.php
-
-Move NAMEDATALEN from postgres_ext.h to pg_config_manual.h
Consider making NAMEDATALEN more configurable in future releases
Update our code to handle 64-bit timezone files to match the zic
source code, which now uses them
Have configure choose integer datetimes by default
http://archives.postgresql.org/pgsql-patches/2007-05/msg00046.php
-
-
-Fix problem with excessive logging during SSL disconnection
-
http://archives.postgresql.org/pgsql-bugs/2006-12/msg00122.php
-
http://archives.postgresql.org/pgsql-bugs/2007-05/msg00065.php
Support scoped IPv6 addresses
http://archives.postgresql.org/pgsql-bugs/2007-05/msg00111.php
Improve signal handling
http://archives.postgresql.org/pgsql-patches/2005-06/msg00027.php
-
-Add long file support for binary pg_dump output
Wire Protocol Changes
of result sets using new statement protocol
Add pre-parsing phase that converts non-ISO syntax to supported
http://archives.postgresql.org/pgsql-hackers/2006-10/msg01527.php
-
3">Features We Do Not Want
+
1">Features We Do Not Want
All backends running as threads in a single process (not wanted)
projects / postgresql.git / commitdiff