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Update FAQ.

This commit is contained in:
Bruce Momjian
2001-05-30 23:00:41 +00:00
parent e07d894990
commit 227a584655
2 changed files with 7 additions and 7 deletions

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Frequently Asked Questions (FAQ) for PostgreSQL Frequently Asked Questions (FAQ) for PostgreSQL
Last updated: Wed May 30 18:57:52 EDT 2001 Last updated: Wed May 30 19:00:33 EDT 2001
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us) Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
@ -709,9 +709,9 @@ Maximum number of indexes on a table? unlimited
column statistics on its own, so VACUUM ANALYZE must be run to collect column statistics on its own, so VACUUM ANALYZE must be run to collect
them periodically. them periodically.
Indexes are usually not used for ORDER BY or joins: a sequential scan Indexes are usually not used for ORDER BY or joins. A sequential scan
followed by an explicit sort is faster than an indexscan of all tuples followed by an explicit sort is faster than an indexscan of all tuples
of a large table, because it takes fewer disk accesses. of a large table. This is because random disk access is very slow.
When using wild-card operators such as LIKE or ~, indices can only be When using wild-card operators such as LIKE or ~, indices can only be
used if the beginning of the search is anchored to the start of the used if the beginning of the search is anchored to the start of the

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alink="#0000FF"> alink="#0000FF">
<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1> <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
<P>Last updated: Wed May 30 18:57:52 EDT 2001</P> <P>Last updated: Wed May 30 19:00:33 EDT 2001</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>
@ -908,9 +908,9 @@ Maximum number of indexes on a table? unlimited
periodically.</P> periodically.</P>
<P>Indexes are usually not used for <SMALL>ORDER BY</SMALL> <P>Indexes are usually not used for <SMALL>ORDER BY</SMALL>
or joins: a sequential scan followed by an explicit sort is or joins. A sequential scan followed by an explicit sort is
faster than an indexscan of all tuples of a large table, because it faster than an indexscan of all tuples of a large table. This
takes fewer disk accesses.</P> is because random disk access is very slow.</P>
<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> indices can only be used if the beginning of the search <I>~,</I> indices can only be used if the beginning of the search