From 032858216caa0e820ddfe32ec4cd91a2de31a6b4 Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Fri, 24 Feb 2006 15:00:48 +0000 Subject: Backpatch FAQ changes to 8.1.X. --- doc/src/FAQ/FAQ.html | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) (limited to 'doc/src/FAQ') diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html index 3c10b91607a..7359ba271dc 100644 --- a/doc/src/FAQ/FAQ.html +++ b/doc/src/FAQ/FAQ.html @@ -10,7 +10,7 @@ alink="#0000ff">

Frequently Asked Questions (FAQ) for PostgreSQL

-

Last updated: Sun Feb 12 12:15:49 EST 2006

+

Last updated: Fri Feb 24 09:59:35 EST 2006

Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us) @@ -742,16 +742,8 @@ table?unlimited usually faster than an index scan of a large table.

However, LIMIT combined with ORDER BY often will use an index because only a small portion of the table - is returned. In fact, though MAX() and MIN() don't use indexes, - it is possible to retrieve such values using an index with ORDER BY - and LIMIT: -
-    SELECT col
-    FROM tab
-    ORDER BY col [ DESC ]
-    LIMIT 1;
-
- + is returned.

+

If you believe the optimizer is incorrect in choosing a sequential scan, use SET enable_seqscan TO 'off' and run query again to see if an index scan is indeed faster.

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