In Analysis Services 2000, there was no choice but to build the dimensions first
and then build the cube. Analysis Services 2005 allows for the creation of the cube
without first creating the dimensions. Instead, the cube building wizard can create
the dimensions are part of the process. If it sounds tempting to simply walk through
the cube building wizard and let it create the dimensions, it is. Note, however,
that no matter how well the wizard does its work, it??™s almost a certainty that the
dimensions will require some tweaks after they have been generated.
Building a new cube can be as simple as launching a wizard. Cubes only
understand DSVs, so the wizard will ask what DSV to use in creating the cube.
Upon examining the dimensions in the DSV, the wizard can try to build attributes
and hierarchies for the dimensions. There is nothing wrong with this, but by default
nearly every column in the dimension table will become an attribute, and this can
lead to many attributes that may confuse end users. Secondly, the hierarchies as
determined by the wizard are often incomplete or just plain silly, so fixes are often
required there.
The Cube Wizard, as it is called, reads the DSV and tries to determine which
tables are dimension tables and which are fact tables. Note that the wizard makes
no use of the table names, so having the words ???fact??? and ???dim??? in the title does
nothing to help the wizard. Instead, it looks at the relationships and tries to determine
which tables belong in each category.
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