Overview
Explanation
A Cube acts as an OLAP database to the subscribers who need to
query data from an OLAP data store. A Cube is the main object of a SSAS
solution where the majority of fine tuning, calculations, aggregation
design, storage design, defining relationship and a lot of other
configurations are developed. We will create a cube using our dimension
and fact tables.
Explanation
Right-click the Cube folder and select “New Cube”, and it will
invoke the Cube Wizard. In the first screen you need to select one of the
methods of creating a Cube. We already have our dimensions ready, and schema is
already designed to contain dimension and fact tables. So we will select the
option of “Use existing tables”.
In the next screen, we
need to select the tables which will be used to create measure groups. We
already have a DSV which has fact tables in the schema. So we will use this as
shown in the below screenshot.
In the next screen, we
need to select the tables which will be used to create measure groups. We
already have a DSV which has fact tables in the schema. So we will use this as
shown in the below screenshot.
In this screen you need to
select any existing dimensions. We have created three dimensions and we will
include all of these dimensions as shown below.
In the next screen, we can
select if we want to create any additional new dimensions from the tables
available in the DSV. We do not want to create any more dimensions, so unselect
any selected tables as shown below and move to the next screen.
Finally you need to name
your cube, which is the last step of the wizard before your cube is created.
Name it something appropriate like “Sales Cube” as shown below.
Now your cube should have been created and
if your cube editor is open you should find different tabs to configure and
design various features and aspects of the cube. If you look carefully in the
below screenshot, you will find FactInternetSales and FactResellerSales measure
groups. Also you will find Sales Territory and Product dimension, but Date
dimension is missing. Both fact tables have multiple fields referencing the Date
Key from the Date dimension.
BIDS
intelligently creates three dimensions from the Date dimension and names them
to the name of the field which is referenced from the Date dimension. So you
will find three compounds of Date dimension – Ship Date, Due Date and Order
Date dimensions. These are known as role-playing dimensions.
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