Dimensional modeling: Attribut from different table

[backhandx]

Hi all,

I  would like to know if it is proper in a level, to populate it with attributs from 2 tables. Actually, I want to select, in a level, a column from table A as businesskey and a column from table B as membercaption.
is this could impact the exection time of report which are based on this level?

Thanks

[MFGF]

Hi all,

I  would like to know if it is proper in a level, to populate it with attributs from 2 tables. Actually, I want to select, in a level, a column from table A as businesskey and a column from table B as membercaption.
is this could impact the exection time of report which are based on this level?

Thanks

Hi,

If you think about it, the answer has to be yes. Really the question you're asking is whether it's quicker to retrieve two items from a single table, or to retrieve two items from a pair of joined tables. As the database is having to do more work and handle a more complex query in the latter situation, it's invariably going to take more resources which probably means it will take longer to execute. The real question is whether there will be a noticeable difference as far as a user is concerned. The answer is going to depend on the volumes of rows in the tables, the complexity of the join and the capabilities of the database's query optimizer. Only you have the knowledge to investigate and answer those, though.

Cheers!

MF.

[backhandx]

Hi,

If you think about it, the answer has to be yes. Really the question you're asking is whether it's quicker to retrieve two items from a single table, or to retrieve two items from a pair of joined tables. As the database is having to do more work and handle a more complex query in the latter situation, it's invariably going to take more resources which probably means it will take longer to execute. The real question is whether there will be a noticeable difference as far as a user is concerned. The answer is going to depend on the volumes of rows in the tables, the complexity of the join and the capabilities of the database's query optimizer. Only you have the knowledge to investigate and answer those, though.

Cheers!

MF.

Actually, the table A contains idA and the table B contains information about  the idA. So, I am wondering that if I use the member caption from a column in the table B and the businessKey from the table A not the table B, cognos will generate a SQL code without a join between the table A and B. Is this correct?

[Invisi]

Are we talking Data Vault?