diff --git a/doc/FAQ b/doc/FAQ index b09bf2abc3725825c58b001124038b213988f8e8..b44997cd16ac24a2aa222c57bf193ccffd37ab88 100644 --- a/doc/FAQ +++ b/doc/FAQ @@ -1,7 +1,7 @@ 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) @@ -569,14 +569,8 @@ sequential scan followed by an explicit sort is 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; - + only a small portion of the table 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. diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html index 3c10b91607a7c1e218ea85869a0058b4615764e5..7359ba271dcea48fcf0028501e2cc076e96aa008 100644 --- a/doc/src/FAQ/FAQ.html +++ b/doc/src/FAQ/FAQ.html @@ -10,7 +10,7 @@ alink="#0000ff">
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?
- 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.