Weird union behaviour

[Guest_imported]

Hi all,
My oracle table looks like

Card 1 Card 2
------ ------
rows count: 7854

In Query Manager, in my first query
I put Card1

And then I put a union join
I put Card2

A quick check with the rows retrieved, I only got 6000+ rows only. Shouldn't it be 7854 * 2 ???

 

[ATP]

A union query also does a Distinct.

So if you have duplicate rows in a table or the same values in both tables then this will reduce the row count.

 

[PAULSGS]

ATP is quite correct, you can get the correct result from a UNION ALL, supported by Oracle, but I don't think BO will generate it, so you could manually edit the Data Provider's SQL, if this is appropriate.