Date |Sat, 4 Aug 2001 12:53:15 +0100
>From |"Tadej Guzej" <[EMAIL PROTECTED]>
Hello!
TG> What is better:
TG> CREATE INDEX ix1(field1, field2, field3);
TG> or
TG> CREATE INDEX ix1(field1), ix2(field2), ix3(field3);
TG> I have a large table of some 30,000,000 records and am wondering
TG> which indexing gives better performance and why.
TG> How do I optimize search on this table - I'm using lots of OR statements in WHERE
clause.
TG> Thanks in advance,
Quote:
MySQL uses multiple-column indexes in such a way that queries are fast when you
specify a known quantity for the first column of the index in a WHERE clause, even if
you don't specify values for the other columns.
http://www.mysql.com/doc/M/u/Multiple-column_indexes.html
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