This depend only on reduction scale.If your particullar queries have many
duplicates e.g 90% or more, than separate distinct can be better from resource
POV. But if it is opposite, then eliminate particular distinct operations can
have huge performance boost.Regards,Karol Bieniaszewski
Hi,
Not important, just got curious: Consider a query like this:
select c1 from t1
union select c1 from t2;
This will eliminate all duplicates, since I didn't specify "union all".
But would this be more or less efficient than (or the same as) this:
select distinct c1 from t1
union
The error was:
Gbak error: I/O error for file “c:\fbThe system cannot find file specified.”
Gbak error: Error while trying to open file.
Gbak error: The system cannot find the file specified.
Thanks!
Kevin
> On Jan 1, 2020, at 2:03 PM, Norman Dunbar nor...@dunbar-it.co.uk
>
