From: Bruce Momjian Date: Mon, 23 Jun 2008 20:20:54 +0000 (+0000) Subject: Add TODO: X-Git-Tag: REL8_4_BETA1~1259 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=01930cea035d4fd9e490a2d1159b26fbd2f43ef3;p=thirdparty%2Fpostgresql.git Add TODO: * Consider whether duplicate keys should be sorted by block/offset http://archives.postgresql.org/pgsql-hackers/2008-03/msg00558.php Create new "Sorting" TODO section. --- diff --git a/doc/TODO b/doc/TODO index faaafd5c658..1611c21c2b8 100644 --- a/doc/TODO +++ b/doc/TODO @@ -1,7 +1,7 @@ PostgreSQL TODO List ==================== Current maintainer: Bruce Momjian (bruce@momjian.us) -Last updated: Wed Jun 18 21:15:40 EDT 2008 +Last updated: Mon Jun 23 16:20:35 EDT 2008 The most recent version of this document can be viewed at http://www.postgresql.org/docs/faqs.TODO.html. @@ -1388,6 +1388,25 @@ Indexes o Allow multi-column hash indexes o -During index creation, pre-sort the tuples to improve build speed +Sorting +======= +* Consider using hash buckets to do DISTINCT, rather than sorting + + This would be beneficial when there are few distinct values. This is + already used by GROUP BY. + +* Consider whether duplicate keys should be sorted by block/offset + + http://archives.postgresql.org/pgsql-hackers/2008-03/msg00558.php + +* -Avoid tuple some tuple copying in sort routines +* Consider being smarter about memory and external files used during + sorts + + http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php + http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php + +* Consider detoasting keys before sorting Fsync @@ -1711,11 +1730,6 @@ Optimizer / Executor http://archives.postgresql.org/pgsql-hackers/2007-11/msg00771.php -* Consider using hash buckets to do DISTINCT, rather than sorting - - This would be beneficial when there are few distinct values. This is - already used by GROUP BY. - * Log statements where the optimizer row estimates were dramatically different from the number of rows actually found? * Consider compressed annealing to search for query plans @@ -1865,7 +1879,6 @@ Miscellaneous Performance http://archives.postgresql.org/pgsql-hackers/2008-01/msg01119.php -* -Avoid tuple some tuple copying in sort routines * SMP scalability improvements http://archives.postgresql.org/pgsql-hackers/2007-07/msg00439.php @@ -1876,12 +1889,6 @@ Miscellaneous Performance http://archives.postgresql.org/pgsql-hackers/2007-09/msg00895.php -* Consider being smarter about memory and external files used during - sorts - - http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php - http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php - * Allow one transaction to see tuples using the snapshot of another transaction @@ -1917,7 +1924,6 @@ Source Code http://archives.postgresql.org/pgsql-hackers/2006-09/msg02238.php http://archives.postgresql.org/pgsql-patches/2006-10/msg00048.php -* Consider detoasting keys before sorting * Consider GnuTLS if OpenSSL license becomes a problem http://archives.postgresql.org/pgsql-patches/2006-05/msg00040.php diff --git a/doc/src/FAQ/TODO.html b/doc/src/FAQ/TODO.html index 825bb888505..844dc553ddd 100644 --- a/doc/src/FAQ/TODO.html +++ b/doc/src/FAQ/TODO.html @@ -8,7 +8,7 @@

PostgreSQL TODO List

Current maintainer: Bruce Momjian (bruce@momjian.us)
-Last updated: Wed Jun 18 21:15:40 EDT 2008 +Last updated: Mon Jun 23 16:20:35 EDT 2008

The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html. @@ -1203,7 +1203,24 @@ first. There is also a developer's wiki at

Allow multi-column hash indexes

-During index creation, pre-sort the tuples to improve build speed

Fsync

Sorting

Consider using hash buckets to do DISTINCT, rather than sorting +
This would be beneficial when there are few distinct values. This is + already used by GROUP BY. +
+
Consider whether duplicate keys should be sorted by block/offset +
http://archives.postgresql.org/pgsql-hackers/2008-03/msg00558.php +
+
-Avoid tuple some tuple copying in sort routines +
Consider being smarter about memory and external files used during + sorts +
http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php + http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php +
+
Consider detoasting keys before sorting +

Fsync

Determine optimal fdatasync/fsync, O_SYNC/O_DSYNC options @@ -1216,7 +1233,7 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-hackers/2007-06/msg00541.php

Cache Usage

Speed up COUNT(*) @@ -1277,7 +1294,7 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-hackers/2007-11/msg00562.php

Vacuum

Improve speed with indexes @@ -1345,7 +1362,7 @@ first. There is also a developer's wiki at

Locking

Fix priority ordering of read and write light-weight locks (Neil) @@ -1375,7 +1392,7 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-hackers/2008-01/msg00873.php

Startup Time Improvements

Experiment with multi-threaded backend for backend creation @@ -1386,7 +1403,7 @@ first. There is also a developer's wiki at
a single session using multiple threads to execute a statement faster.

Write-Ahead Log

Eliminate need to write full pages to WAL before page modification @@ -1469,7 +1486,7 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-hackers/2007-11/msg00035.php

Optimizer / Executor

Improve selectivity functions for geometric operators @@ -1480,10 +1497,6 @@ first. There is also a developer's wiki at
actual row counts differ by a specified percentage
Improve how ANALYZE computes in-doubt tuples
http://archives.postgresql.org/pgsql-hackers/2007-11/msg00771.php -
-
Consider using hash buckets to do DISTINCT, rather than sorting -
This would be beneficial when there are few distinct values. This is - already used by GROUP BY.
Log statements where the optimizer row estimates were dramatically different from the number of rows actually found? @@ -1498,7 +1511,7 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-hackers/2007-05/msg00450.php

Background Writer

Consider having the background writer update the transaction status @@ -1522,7 +1535,7 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-patches/2007-06/msg00340.php

Miscellaneous Performance

Do async I/O for faster random read-ahead of data @@ -1608,7 +1621,6 @@ first. There is also a developer's wiki at
Sort large UPDATE/DELETEs so it is done in heap order
http://archives.postgresql.org/pgsql-hackers/2008-01/msg01119.php
-
-Avoid tuple some tuple copying in sort routines
SMP scalability improvements
http://archives.postgresql.org/pgsql-hackers/2007-07/msg00439.php http://archives.postgresql.org/pgsql-hackers/2007-09/msg00206.php @@ -1616,11 +1628,6 @@ first. There is also a developer's wiki at
Research reducing deTOASTing in more places
http://archives.postgresql.org/pgsql-hackers/2007-09/msg00895.php -
-
Consider being smarter about memory and external files used during - sorts -
http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php - http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php
Allow one transaction to see tuples using the snapshot of another transaction @@ -1628,7 +1635,7 @@ first. There is also a developer's wiki at
http://archives.postgresql.org/pgsql-hackers/2008-01/msg00400.php

Source Code

Add use of 'const' for variables in source tree @@ -1653,7 +1660,6 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-hackers/2006-09/msg02238.php http://archives.postgresql.org/pgsql-patches/2006-10/msg00048.php
-
Consider detoasting keys before sorting
Consider GnuTLS if OpenSSL license becomes a problem
http://archives.postgresql.org/pgsql-patches/2006-05/msg00040.php http://archives.postgresql.org/pgsql-hackers/2006-12/msg01213.php @@ -1749,7 +1755,7 @@ first. There is also a developer's wiki at
of result sets using new statement protocol

Exotic Features

Add pre-parsing phase that converts non-ISO syntax to supported @@ -1777,7 +1783,7 @@ first. There is also a developer's wiki at

http://archives.postgresql.org/pgsql-hackers/2008-01/msg00893.php

Features We Do Not Want

All backends running as threads in a single process (not wanted)