they are not equivalent, the first is an outer join, the second an inner
join

>From: "sean_brad" <sean_brad@...>
>Reply-To: ib-support@yahoogroups.com
>To: ib-support@yahoogroups.com
>Subject: [ib-support] Speed of Joins
>Date: Thu, 02 May 2002 12:16:14 -0000
>
>Hi
>
>I use a join select statement of the following form:
>
>SELECT A,B,C
>FROM Table1 LEFT OUTER JOIN Table2
>ON Table2.D = Table1.D and
> Table2.E = Table1.E
>Where F like 'text%'
>
>But have found it to be very slow.
>
>(The fields used in the join and in the Where clause are indexed)
>
>I've tried replacing it with:
>
>SELECT A,B,C
>FROM Table1, Table2
>Where Table2.D = Table1.D and
> Table2.E = Table1.E and
> F like 'text%'
>
>and the result set is returned much quicker.
>
>Can any one explain why the first method is so much slower. And, if
>there is a good reason for using it, is there a way of speeding it up?
>
>Thanks for any help,
>
>Sean
>
>
>

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