Set the Dimension Storage Type
There are two types of dimension storage available for an Essbase block storage database: dense, and sparse. Dense dimensions have most of the data points filled, while sparse dimensions have most of the data points empty. The default storage type is sparse, but at least one dense dimension is required.
To assign or change the dimension storage type using the Essbase web interface, open the outline for editing, select a top dimension member, and edit its general properties. Change Dimension storage type from sparse to dense, or from dense to sparse.
If you are using an application workbook to design the cube, you assign the Storage Type for each dimension on the Essbase.Cube worksheet. Refer to Understand the Essbase.Cube Worksheet.
If you use REST API to change the outline, you would update the storage property of the dimension when performing an add or update action, as documented in the endpoint for Run Batch Outline Edit.