Union versus Aggregation

[c83user]

When I use union the report performance is very slow.What is the workaround ?Can I still get the data I need and not use a union.I have too many union queries.(I'm using Union in Report Studio)

 

[blom0344]

Can I still get the data I need and not use a union

That is impossible to answer without knowing more on what you need to report on (data;queries)
Large union can be performance killers due to the fact that sorting is required to eliminate duplicate records.
Perhaps if you can show us an example, we can suggests alternatives..

Ties Blom

 

[c83user]

I have table A and Table B which has a date field in common.A has some inventory 1 and B has inventory 2.I need to add these inventory values to show up in the crosstab with separate filters on inventory 1 and 2.What could be used instead of union.Join on date instead of union does not give correct data.

 

[blom0344]

Join 2 facts is never a valid option. You need to make sure that both facts A and B are joined to a common date dimension. (in the model) Then Cognos can perform a multifact query (stitch both facts on the server) and the result may be a better performer.

Ties Blom