Database Reference
In-Depth Information
The advantages of a single cube approach are as follows:
•
All of your data is in one place. If your users need to display measures
from multiple measure groups in a single query, or you need to create
calculations that span measure groups, a single cube is the only practical
option. Although it is possible to write queries and calculations that return
data from multiple cubes, all of the ways of doing this have quite serious
side-effects on performance and should be avoided. This is a very important
point and the main reason that the single cube approach should be the one
you should start with.
•
You only have one cube to manage security and calculations on; with multiple
cubes the same security and calculations might have to be duplicated.
The advantages of the multiple cube approach are as follows:
•
Query performance may be better. In previous versions of Analysis
Services, it was sometimes the case that splitting up a cube would improve
performance; with Analysis Services 2012, these scenarios are rare but still
occur, typically when there are complex MDX calculations.
•
If you have a cube with many measures, measure groups, dimensions, and
hierarchies, but have to use Standard Edition, you cannot use perspectives to
hide complexity from your users. In this case, creating multiple cubes might
be a more user-friendly approach.
•
Depending on your requirements, security might be easier to manage with
multiple cubes. It's very easy to grant or deny a role access to a cube; it's
much harder to use dimension security to control which measures and
dimensions in a multi-measure group cube a role can access.
•
If you have complex calculations, especially MDX Script assignments,
it's too easy to write a calculation that has an effect on part of the cube
you didn't want to alter. With multiple cubes, the chances of this happening
are reduced.
•
Maintenance will be easier with multiple cubes. For example, if you ever
need to do a full process on a dimension then all cubes where that dimension
is used will need a full process as well. With the single cube approach, this
means you will have to reprocess all of your measure groups; with the
multiple cube approach, you will only have to reprocess the cubes where
that dimension is used.
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