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What
Is Multidimensional Analysis?
Multidimensional analysis is uses
dimensions and measures to analyse data. To do this
using Business Intelligence tools such as Cognos 8 you
usually need to first model your data dimensionally.
Dimensions are hierarchies and
have one or more levels. What dimensions you define
depends on your data and your business model. A Location
dimension might look like this, for example:
The user can look at the data
at any level – for example Team level will show
totals of all the members of that team, at Area level
you will see the total for all teams within that area.
Measures are usually quantities
such as quantity sold, total revenue and so on. Once
a measure is selected in the analysis the measure is
aggregated to the level you are analysing at. So if
you are analysing at Area level
and you have selected the total
revenue as your measure, you would see the total revenue,
aggregated to Area level.
Often the data you require will
be organised into a data warehouse consisting of dimensional
and fact tables and produced by a skilled data warehouse
team.
The data is then modelled as metadata
and published to make it available for analysis. In
Cognos 8 this is achieved using Framework Manager. Hierarchies
for each dimension are stored in the model so do not
need to be defined by the user.
OLAP Data Sources – sometimes
the data source itself is dimensional, for example a
SAP B/W cube or a Cognos Powercube. These data sources
can be input directly into the Framework model and do
not require further modelling.
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