13.08.2013 11:55, Dimitry Sibiryakov wrote:
>
> Because plans are read from bottom to the top, I would prefer something like
> this:
>
> (A)
>
> Select Expression
> -> Aggregate
> -> Sort (unique)
> -> Table "RDB$RELATIONS" Access By ID
> -> Index "RDB$INDEX_0" Scan
Now imagine two aggregate functions with DISTINCT inside:
Select Expression
-> Aggregate
-> Sort (unique)
-> Sort (unique)
-> Table "RDB$RELATIONS" Access By ID
-> Index "RDB$INDEX_0" Scan
Is it understandable that sorts are independent from each other but both
dependent from the retrieval? I don't think so.
Dmitry
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