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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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