diff --git a/doc/TODO b/doc/TODO index faaafd5c658c4c1448e603c883294182ff32696c..1611c21c2b8eeb8f9904cb15f13809b45dce216f 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 825bb8885058da1284f919c2fb3e9c96ccb4b889..844dc553dddeb8c913e65979c274d505571e81c1 100644 --- a/doc/src/FAQ/TODO.html +++ b/doc/src/FAQ/TODO.html @@ -8,7 +8,7 @@ <body bgcolor="#FFFFFF" text="#000000" link="#FF0000" vlink="#A00000" alink="#0000FF"> <h1><a name="section_1">PostgreSQL TODO List</a></h1> <p>Current maintainer: Bruce Momjian (<a href="mailto:bruce@momjian.us">bruce@momjian.us</a>)<br/> -Last updated: Wed Jun 18 21:15:40 EDT 2008 +Last updated: Mon Jun 23 16:20:35 EDT 2008 </p> <p>The most recent version of this document can be viewed at<br/> <a href="http://www.postgresql.org/docs/faqs.TODO.html">http://www.postgresql.org/docs/faqs.TODO.html</a>. @@ -1203,7 +1203,24 @@ first. There is also a developer's wiki at<br/> </li><li>Allow multi-column hash indexes </li><li>-<em>During index creation, pre-sort the tuples to improve build speed</em> </li></ul> -<h1><a name="section_13">Fsync</a></h1> +<h1><a name="section_13">Sorting</a></h1> +<ul> + <li>Consider using hash buckets to do DISTINCT, rather than sorting +<p> This would be beneficial when there are few distinct values. This is + already used by GROUP BY. +</p> + </li><li>Consider whether duplicate keys should be sorted by block/offset +<p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-03/msg00558.php">http://archives.postgresql.org/pgsql-hackers/2008-03/msg00558.php</a> +</p> + </li><li>-<em>Avoid tuple some tuple copying in sort routines</em> + </li><li>Consider being smarter about memory and external files used during + sorts +<p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php</a> + <a href="http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php">http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php</a> +</p> + </li><li>Consider detoasting keys before sorting +</li></ul> +<h1><a name="section_14">Fsync</a></h1> <ul> <li>Determine optimal fdatasync/fsync, O_SYNC/O_DSYNC options @@ -1216,7 +1233,7 @@ first. There is also a developer's wiki at<br/> <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-06/msg00541.php">http://archives.postgresql.org/pgsql-hackers/2007-06/msg00541.php</a> </p> </li></ul> -<h1><a name="section_14">Cache Usage</a></h1> +<h1><a name="section_15">Cache Usage</a></h1> <ul> <li>Speed up COUNT(*) @@ -1277,7 +1294,7 @@ first. There is also a developer's wiki at<br/> <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg00562.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg00562.php</a> </p> </li></ul> -<h1><a name="section_15">Vacuum</a></h1> +<h1><a name="section_16">Vacuum</a></h1> <ul> <li>Improve speed with indexes @@ -1345,7 +1362,7 @@ first. There is also a developer's wiki at<br/> </p> </li></ul> </li></ul> -<h1><a name="section_16">Locking</a></h1> +<h1><a name="section_17">Locking</a></h1> <ul> <li>Fix priority ordering of read and write light-weight locks (Neil) @@ -1375,7 +1392,7 @@ first. There is also a developer's wiki at<br/> <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00873.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00873.php</a> </p> </li></ul> -<h1><a name="section_17">Startup Time Improvements</a></h1> +<h1><a name="section_18">Startup Time Improvements</a></h1> <ul> <li>Experiment with multi-threaded backend for backend creation @@ -1386,7 +1403,7 @@ first. There is also a developer's wiki at<br/> a single session using multiple threads to execute a statement faster. </p> </li></ul> -<h1><a name="section_18">Write-Ahead Log</a></h1> +<h1><a name="section_19">Write-Ahead Log</a></h1> <ul> <li>Eliminate need to write full pages to WAL before page modification @@ -1469,7 +1486,7 @@ first. There is also a developer's wiki at<br/> <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg00035.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg00035.php</a> </p> </li></ul> -<h1><a name="section_19">Optimizer / Executor</a></h1> +<h1><a name="section_20">Optimizer / Executor</a></h1> <ul> <li>Improve selectivity functions for geometric operators @@ -1480,10 +1497,6 @@ first. There is also a developer's wiki at<br/> actual row counts differ by a specified percentage </li><li>Improve how ANALYZE computes in-doubt tuples <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg00771.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg00771.php</a> -</p> - </li><li>Consider using hash buckets to do DISTINCT, rather than sorting -<p> This would be beneficial when there are few distinct values. This is - already used by GROUP BY. </p> </li><li>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<br/> <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-05/msg00450.php">http://archives.postgresql.org/pgsql-hackers/2007-05/msg00450.php</a> </p> </li></ul> -<h1><a name="section_20">Background Writer</a></h1> +<h1><a name="section_21">Background Writer</a></h1> <ul> <li>Consider having the background writer update the transaction status @@ -1522,7 +1535,7 @@ first. There is also a developer's wiki at<br/> <p> <a href="http://archives.postgresql.org/pgsql-patches/2007-06/msg00340.php">http://archives.postgresql.org/pgsql-patches/2007-06/msg00340.php</a> </p> </li></ul> -<h1><a name="section_21">Miscellaneous Performance</a></h1> +<h1><a name="section_22">Miscellaneous Performance</a></h1> <ul> <li>Do async I/O for faster random read-ahead of data @@ -1608,7 +1621,6 @@ first. There is also a developer's wiki at<br/> </li><li>Sort large UPDATE/DELETEs so it is done in heap order <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg01119.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg01119.php</a> </p> - </li><li>-<em>Avoid tuple some tuple copying in sort routines</em> </li><li>SMP scalability improvements <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-07/msg00439.php">http://archives.postgresql.org/pgsql-hackers/2007-07/msg00439.php</a> <a href="http://archives.postgresql.org/pgsql-hackers/2007-09/msg00206.php">http://archives.postgresql.org/pgsql-hackers/2007-09/msg00206.php</a> @@ -1616,11 +1628,6 @@ first. There is also a developer's wiki at<br/> </p> </li><li>Research reducing deTOASTing in more places <p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-09/msg00895.php">http://archives.postgresql.org/pgsql-hackers/2007-09/msg00895.php</a> -</p> - </li><li>Consider being smarter about memory and external files used during - sorts -<p> <a href="http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php">http://archives.postgresql.org/pgsql-hackers/2007-11/msg01101.php</a> - <a href="http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php">http://archives.postgresql.org/pgsql-hackers/2007-12/msg00045.php</a> </p> </li><li>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<br/> <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00400.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00400.php</a> </p> </li></ul> -<h1><a name="section_22">Source Code</a></h1> +<h1><a name="section_23">Source Code</a></h1> <ul> <li>Add use of 'const' for variables in source tree @@ -1653,7 +1660,6 @@ first. There is also a developer's wiki at<br/> <p> <a href="http://archives.postgresql.org/pgsql-hackers/2006-09/msg02238.php">http://archives.postgresql.org/pgsql-hackers/2006-09/msg02238.php</a> <a href="http://archives.postgresql.org/pgsql-patches/2006-10/msg00048.php">http://archives.postgresql.org/pgsql-patches/2006-10/msg00048.php</a> </p> - </li><li>Consider detoasting keys before sorting </li><li>Consider GnuTLS if OpenSSL license becomes a problem <p> <a href="http://archives.postgresql.org/pgsql-patches/2006-05/msg00040.php">http://archives.postgresql.org/pgsql-patches/2006-05/msg00040.php</a> <a href="http://archives.postgresql.org/pgsql-hackers/2006-12/msg01213.php">http://archives.postgresql.org/pgsql-hackers/2006-12/msg01213.php</a> @@ -1749,7 +1755,7 @@ first. There is also a developer's wiki at<br/> of result sets using new statement protocol </li></ul> </li></ul> -<h1><a name="section_23">Exotic Features</a></h1> +<h1><a name="section_24">Exotic Features</a></h1> <ul> <li>Add pre-parsing phase that converts non-ISO syntax to supported @@ -1777,7 +1783,7 @@ first. There is also a developer's wiki at<br/> <p> <a href="http://archives.postgresql.org/pgsql-hackers/2008-01/msg00893.php">http://archives.postgresql.org/pgsql-hackers/2008-01/msg00893.php</a> </p> </li></ul> -<h1><a name="section_24">Features We Do <u>Not</u> Want</a></h1> +<h1><a name="section_25">Features We Do <u>Not</u> Want</a></h1> <ul> <li>All backends running as threads in a single process (not wanted)