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Thread: query takes a long time

query takes a long time

From
Garry Saddington
Date:

Can someone suggest how I could speed up the execution of this query?

select count(distinct attendance.studentid)

from attendance

where attendance.studentid not in (select studentid from attendance where auth not in('C','E','F','G','H','I','M','N','O','R','S','T','U'))

It returns the correct results but very slowly.

regards

garry

Re: query takes a long time

From
"marcin mank"
Date:

select count(distinct attendance.studentid)

from attendance

where attendance.studentid not in (select studentid from attendance where auth not in('C','E','F','G','H','I','M','N','O','R','S','T','U'))


I am tired a lot now, but isn`t it the same as:

select count(distinct attendance.studentid)

from attendance

where auth in('C','E','F','G','H','I','M','N','O','R','S','T','U')
?