From 71f8127bc677014223d47504c344d73655ad5c8e Mon Sep 17 00:00:00 2001 From: Bruce Momjian <bruce@momjian.us> Date: Sat, 5 May 2007 03:14:40 +0000 Subject: [PATCH] Done: > * -Allow ORDER BY ... LIMIT # to select high/low value without sort or < < Right now, if no index exists, ORDER BY ... LIMIT # requires we sort < all values to return the high/low value. Instead The idea is to do a < sequential scan to find the high/low value, thus avoiding the sort. < MIN/MAX already does this, but not for LIMIT > 1. < --- doc/TODO | 10 ++-------- doc/src/FAQ/TODO.html | 9 ++------- 2 files changed, 4 insertions(+), 15 deletions(-) diff --git a/doc/TODO b/doc/TODO index d231db43f1f..047d4f9c557 100644 --- a/doc/TODO +++ b/doc/TODO @@ -2,7 +2,7 @@ PostgreSQL TODO List ==================== Current maintainer: Bruce Momjian (bruce@momjian.us) -Last updated: Sun Apr 29 03:17:05 EDT 2007 +Last updated: Fri May 4 23:14:29 EDT 2007 The most recent version of this document can be viewed at http://www.postgresql.org/docs/faqs.TODO.html. @@ -1361,14 +1361,8 @@ Optimizer / Executor ==================== * Improve selectivity functions for geometric operators -* Allow ORDER BY ... LIMIT # to select high/low value without sort or +* -Allow ORDER BY ... LIMIT # to select high/low value without sort or index using a sequential scan for highest/lowest values - - Right now, if no index exists, ORDER BY ... LIMIT # requires we sort - all values to return the high/low value. Instead The idea is to do a - sequential scan to find the high/low value, thus avoiding the sort. - MIN/MAX already does this, but not for LIMIT > 1. - * Precompile SQL functions to avoid overhead * Create utility to compute accurate random_page_cost value * Improve ability to display optimizer analysis using OPTIMIZER_DEBUG diff --git a/doc/src/FAQ/TODO.html b/doc/src/FAQ/TODO.html index 73cd36afed8..80c7692eb91 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: Sun Apr 29 03:17:05 EDT 2007 +Last updated: Fri May 4 23:14:29 EDT 2007 </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>. @@ -1210,13 +1210,8 @@ first. There is also a developer's wiki at<br/> <ul> <li>Improve selectivity functions for geometric operators - </li><li>Allow ORDER BY ... LIMIT # to select high/low value without sort or + </li><li>-<em>Allow ORDER BY ... LIMIT # to select high/low value without sort or</em> index using a sequential scan for highest/lowest values -<p> Right now, if no index exists, ORDER BY ... LIMIT # requires we sort - all values to return the high/low value. Instead The idea is to do a - sequential scan to find the high/low value, thus avoiding the sort. - MIN/MAX already does this, but not for LIMIT > 1. -</p> </li><li>Precompile SQL functions to avoid overhead </li><li>Create utility to compute accurate random_page_cost value </li><li>Improve ability to display optimizer analysis using OPTIMIZER_DEBUG -- GitLab