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Update FAQ.

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Bruce Momjian 2002-06-25 01:45:58 +00:00
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doc/FAQ
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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)
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using an index with ORDER BY and LIMIT:
SELECT col
FROM tab
ORDER BY col
ORDER BY col [ DESC ]
LIMIT 1
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
string. Therefore, to use indexes, LIKE patterns must not start with
%, and ~(regular expression) patterns must start with ^.
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, 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?

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doc/src/FAQ/FAQ.html
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alink="#0000ff">
<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=
"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
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<PRE>
SELECT col
FROM tab
ORDER BY col
ORDER BY col [ DESC ]
LIMIT 1
</PRE>
<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,
<SMALL>LIKE</SMALL> patterns must not start with <I>%</I>, and
<I>~</I>(regular expression) patterns must start with <I>^</I>.</P>