When planning your data
storage and design, it is helpful to approximate the size of aggregations.
A basis for estimating aggregation size is the number of distinct
values in a dimension level, otherwise known as cardinality. The other
factor that determines aggregations size is density. Density is a
measure of how many members of each dimension in an aggregation occur
in combination with the members of the other dimensions (For example,
there might not be sales of a specific product on a specific date).
The total cube size, as well as the resources that are available for
the cube build process, determine the build time that is needed. It
is also important to note that build time should not exceed the cube
update interval.
Aggregation size and
available hardware influence your choices for aggregation partitioning.
You can separate aggregations into multiple files. A reduced file
size might accelerate OLAP server access time, particularly if multiple
processors are available for multi-threaded processing. You can use
either pre-aggregated summary tables, the cube's own efficient aggregation
storage, or a combination of both. Using indexes on either storage
type might increase query performance, while also increasing storage
space and build time.