From 0915d370f549e68ec56cf819d0023bb2c237603d Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Fri, 24 Feb 2006 14:59:54 +0000
Subject: [PATCH] Remove mention of MIN/MAX() not using indexes.
---
doc/FAQ | 12 +++---------
doc/src/FAQ/FAQ.html | 14 +++-----------
2 files changed, 6 insertions(+), 20 deletions(-)
diff --git a/doc/FAQ b/doc/FAQ
index b09bf2abc37..b44997cd16a 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 3c10b91607a..7359ba271dc 100644
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -10,7 +10,7 @@
alink="#0000ff">
<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
- <P>Last updated: Sun Feb 12 12:15:49 EST 2006</P>
+ <P>Last updated: Fri Feb 24 09:59:35 EST 2006</P>
<P>Current maintainer: Bruce Momjian (<A href=
"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)
@@ -742,16 +742,8 @@ table?</TD><TD>unlimited</TD></TR>
usually faster than an index scan of a large table.</P>
However, <SMALL>LIMIT</SMALL> combined with <SMALL>ORDER BY</SMALL>
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:
-<PRE>
- SELECT col
- FROM tab
- ORDER BY col [ DESC ]
- LIMIT 1;
-</PRE>
-
+ is returned.</P>
+
<P>If you believe the optimizer is incorrect in choosing a
sequential scan, use <CODE>SET enable_seqscan TO 'off'</CODE> and
run query again to see if an index scan is indeed faster.</P>
--
GitLab