PostgreSQL TODO List

====================

Current maintainer:Bruce Momjian (bruce@momjian.us)

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/2006-08/msg00038.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

* 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

http://archives.postgresql.org/pgsql-patches/2005-06/msg00027.php

o -Add long file support for binary pg_dump output

* Wire Protocol Changes