Creating a Mixed English Query Model
While creating an English Query model, you may find that not all of the questions are answered using the current database. If you have created an OLAP model using the OLAP Project Wizard, you can enable SQL to access the data in the underlying SQL database.
If you create a project without using the OLAP Project Wizard, by default, both SQL and OLAP are enabled. When both Microsoft® SQL Server™ 2000 Analysis Services and SQL are enabled, English Query first tries to answer the question using multidimensional expressions (MDX) and then, if unsuccessful, generates SQL statements for the question.
Using mixed models, you can:
- Ask questions that cannot be answered using only OLAP cubes because the data is not in an OLAP cube but in the underlying SQL database.
- Speed up the retrieval of data for questions that are not about aggregation of data, such as "What products do people buy?".
Before expanding your model by creating a mixed model, consider the following:
- Make sure that your OLAP cube is current with the underlying SQL database. If your OLAP cube and SQL database are not synchronized, you may get erroneous responses to your queries.
Each time that you ask a question, English Query creates a new query using the appropriate database. Follow-up questions provide inconsistent results if the underlying data has changed and the cube has not.
Important You cannot access the underlying database structure of an OLAP cube in an English Query model unless you are a member of the OLAP Administrators group and the Microsoft Windows NT® 4.0 or Windows® 2000 user group on the server with the Analysis Services database for which you are building the model. You must have OLAP Administrator permissions to load the tables underlying the cubes using Decision Support Objects (DSO).
To create a mixed model