Rebuilding Cubes

Once the fact and dimension tables of the data warehouse schema are designed, you can use this information to build the multidimensional cubes. The Rebuild Cubes Wizard transforms fact tables or views into cubes, and dimension tables or views into dimensions. You can then design the cubes taking into account the different analysis axes of the dimensions. These cubes will serve to generate the text files used to create and populate the OLAP engine.

The Rebuild Cubes feature works only if there are tables in the physical diagram with a multidimensional type (Fact or Dimension). You can assign types either manually (see Table Properties) or via the Multidimensional Objects Retrieval Wizard (see Retrieving Multidimensional Objects).

The Rebuild Cubes Wizard creates multidimensional objects in a new or existing multidimensional diagram as follows:

Physical object	After rebuild cubes, creates
Fact table	A fact with the name of the fact table. A cube with the name of the fact table.
Column in a Fact table (except foreign keys)	A measure with the name of the column.
Dimensions tables attached to the fact table	A dimension, named through the concatenation of the dimension tables along the path to the child table, from the furthest to the closest. A hierarchy that becomes the default hierarchy, and which contains attributes corresponding to the primary key columns of the tables converted into a dimension
Column in a Dimension table (except foreign keys)	An attribute, named through the concatenation of the dimension table name and column name if column names are ambiguous. Otherwise the name is identical to the name of the column.
Reference between a fact and a dimension table	A cube dimension association

Select Tools > Multidimension > Rebuild Cubes to open the Cube Rebuild Wizard:
Specify a rebuild mode. You can choose between the following options:
- Delete and Rebuild – all cubes are deleted and rebuilt, including those to which you have made modifications.
- Preserve – only those cubes that have not been modified are deleted and rebuilt. Any cubes that you have modified are preserved.
[optional] Click the Selection tab to specify which tables or views will be used to rebuild cubes. Only those tables and views that have a multidimensional type are available for rebuilding.
Click OK to rebuild cubes.

A message in the Output window informs you that the rebuild is successful. The cube and dimension are created and displayed in a multidimensional diagram.