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Re: count record from two tables with duplicate check

From: Isa <isapmon_at_terra.es>
Date: 14 Sep 2005 01:51:30 -0700
Message-ID: <1126687890.574991.250620@g49g2000cwa.googlegroups.com> 





Hi:


in your select the "distinct" is not necessary, because when you do an
union, the  selected records appear only once.
You can prove without distinct:


Select count(  AAA) from


  (Select emp_num AAA from A


   union all


   Select emp_num AAA from B)



It's can run a little fastest, but I donīt know if it's will be much
better.


Try it,



Regards,


Isa
Received on Wed Sep 14 2005 - 03:51:30 CDT












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