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qry options


qry options

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Tara-1044200
Tara-1044200
UDP Broadcaster
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Group: General Forum Members
Points: 1459 Visits: 3074
I want to do this.

select count(*) from
(
select col1,col2,......col18 from REVemployee.tbemp
group by col1,col2,......col18 HAVING COUNT(*)>1
)a


is there a better way of doing the same for better proformance?
Eugene Elutin
Eugene Elutin
SSCarpal Tunnel
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Group: General Forum Members
Points: 4960 Visits: 5478
Tara-1044200 (6/11/2013)
I want to do this.

select count(*) from
(
select col1,col2,......col18 from REVemployee.tbemp
group by col1,col2,......col18 HAVING COUNT(*)>1
)a


is there a better way of doing the same for better proformance?


Looks fine to me. But you also can try this:


select count(*) from
(
select null a from REVemployee.tbemp
group by col1,col2,......col18 HAVING COUNT(*)>1
)a



You might have slightly better performance.

You can also find duplicates using windowed function, but this very likely to be much slower.

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