Commit 0b584830 authored by Bruce Momjian's avatar Bruce Momjian

Update FAQ.

parent 6918df16
Frequently Asked Questions (FAQ) for PostgreSQL Frequently Asked Questions (FAQ) for PostgreSQL
Last updated: Sun Jun 23 17:16:13 EDT 2002 Last updated: Mon Jun 24 21:45:50 EDT 2002
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us) Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
...@@ -743,13 +743,14 @@ ...@@ -743,13 +743,14 @@
using an index with ORDER BY and LIMIT: using an index with ORDER BY and LIMIT:
SELECT col SELECT col
FROM tab FROM tab
ORDER BY col ORDER BY col [ DESC ]
LIMIT 1 LIMIT 1
When using wild-card operators such as LIKE or ~, indexes can only be When using wild-card operators such as LIKE or ~, indexes can only be
used if the beginning of the search is anchored to the start of the used if the default C local is used during initdb and the beginning of
string. Therefore, to use indexes, LIKE patterns must not start with the search is anchored to the start of the string. Therefore, to use
%, and ~(regular expression) patterns must start with ^. indexes, LIKE patterns must not start with %, and ~(regular
expression) patterns must start with ^.
4.9) How do I see how the query optimizer is evaluating my query? 4.9) How do I see how the query optimizer is evaluating my query?
......
...@@ -14,7 +14,7 @@ ...@@ -14,7 +14,7 @@
alink="#0000ff"> alink="#0000ff">
<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
<P>Last updated: Sun Jun 23 17:16:13 EDT 2002</P> <P>Last updated: Mon Jun 24 21:45:50 EDT 2002</P>
<P>Current maintainer: Bruce Momjian (<A href= <P>Current maintainer: Bruce Momjian (<A href=
"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR> "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
...@@ -946,12 +946,13 @@ ...@@ -946,12 +946,13 @@
<PRE> <PRE>
SELECT col SELECT col
FROM tab FROM tab
ORDER BY col ORDER BY col [ DESC ]
LIMIT 1 LIMIT 1
</PRE> </PRE>
<P>When using wild-card operators such as <SMALL>LIKE</SMALL> or <P>When using wild-card operators such as <SMALL>LIKE</SMALL> or
<I>~</I>, indexes can only be used if the beginning of the search <I>~</I>, indexes can only be used if the default C local is used
during initdb and the beginning of the search
is anchored to the start of the string. Therefore, to use indexes, is anchored to the start of the string. Therefore, to use indexes,
<SMALL>LIKE</SMALL> patterns must not start with <I>%</I>, and <SMALL>LIKE</SMALL> patterns must not start with <I>%</I>, and
<I>~</I>(regular expression) patterns must start with <I>^</I>.</P> <I>~</I>(regular expression) patterns must start with <I>^</I>.</P>
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