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From:Brandon Shuey Date:May 7 1999 7:48pm
Subject:Fundamental Index Question
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My question is how does mysql use indexing in the following example:

cDate=Date_Format(Date_Time,'%Y-%m-%d') just for purposes of this example

	indxLogin		int not null,
	dDate 		Date_Time not null,
	cDate			Date not null,
	LoginTried		char(20),
	PasswdTried		char(20),
	PRIMARY KEY 	(indxLogin),
	INDEX dateIndx 	(cDate,LoginTried)
SELECT dDate,LoginTried,Count(*) FROM tblLogins WHERE dDate >='1999-05-01 00:00:00' and
dDate < '1999-05-02 00:00:00' GROUP BY

Will mysql use the dateIndx?  Shouldn't dateIndx be sorted by dDate, LoginTried and
provide extremely quick results by quickly
finding the matching cDate and performing the group count on only those records?  Am I
thinking of the index in the wrong way?

Brandon Shuey
WebCentric Inc.
(316) 612-8030

Fundamental Index Question(Brandon Shuey)7 May
  • Re: Fundamental Index QuestionChristian Mack10 May