Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations Chriss Miller on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
Joining dimension to dimension
- Thread starter aampham
- Start date
In case of a snowflake schema you will have dimensions joined to dimension. There is nothing inherently wrong with this, but Cognos modelling requires you to reduce the snowflake to a single model query subject. In other words , a fact is only joined to x dimensional objects (without further branching) This results in true starschemas.
Cardinality of a join depends on the nature of the database, there is no such thing as best practice.
The need for defining outer joins can have serious effects on performance though..
Ties Blom
Cardinality of a join depends on the nature of the database, there is no such thing as best practice.
The need for defining outer joins can have serious effects on performance though..
Ties Blom
- Status
Similar threads
