Yes and I believe it's explained in the manual better than I can explain it
here.
Roughly speaking, if the field contains:
foobar
then
LIKE 'foo%' says match anything starting with foo. Since it's STARTING with
foo then the index can be used. Just like the Index of a book would be
useless if you wanted to find references in a book for all words ending in
bar.
LIKE '%foo%' won't use and index either for the same reason.
LIKE '%bar' is right out.
HTH,
Cal
http://www.calevans.com
-----Original Message-----
From: --==[bMan]==-- [mailto:[EMAIL PROTECTED]]
Sent: Monday, March 26, 2001 7:40 PM
To: MySQL List
Subject: Is this a normal behaviour?
O.K. I use MySQL version 3.23 (RedHat 7.0 release) and have a question
about
this query:
1.) [...] LIKE '%pattern'
2.) [...] LIKE 'pattern%'
The first query does not use an index while the second does. Is there any
explenation for this?
Thanks.
--
Bolek,
URL: http://www.bolek.com
URL: http://slash.bolek.com
e-mail: [EMAIL PROTECTED]
ICQ: 4086197, Address: 402905326
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