Re: Help: SQL .*Not IN* alternatives
In article <39dp75$d17@emory.mathcs.emory.edu>, DONALD_BOOTHBY@IMA.ISD.STATE.IN.US says:
>
> I have a user with two flat files who is trying to find data in one
> table that is not in the other.
>...
> He used the following SQL:
> SELECT DISTINCT "idms"."ssn", "idms"."lastname", "idms"."firstname",
> "idms"."mi", "idms"."ssaciid", "idms"."college", "idms"."initials"
> FROM "idms", "ncs"
!!!!!!!
> WHERE ( "idms"."ssn" NOT IN (SELECT DISTINCT "ncs"."ssn" from
> "ncs"))
> ORDER BY "idms"."college" ASC>
> but since these files are large, it was still chugging along 4 hours
>....
You dont need the table "ncs" in the first FROM-list !
There are no columns of this table in your SELECT-list or any
DIRECT condition. The SUBQUERY is NOT a direct condition.
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