The Case Data Model presents the data in one or more virtual tables, depending on the CDSC that is being used to read the underlying data:

This is a single flat table that contains a column for each variable that can be presented in a flattened form. Here is an example of a VDATA table:

Hierarchical data can be represented in VDATA only if it has been defined as expanded. This means that data in unbounded loops cannot be included in VDATA. An unbounded loop is a loop for which the maximum number of iterations is unknown. For more information, see Loops, grids, and levels.

This is a set of hierarchical tables, the top-level table being called HDATA. Each lower-level table represents the data in a loop or grid. For more information, see Understanding hierarchical data.

Some DSCs present the data in both VDATA and HDATA tables. However, hierarchical data that cannot be flattened will not be present in the VDATA tables.

It is also possible to query hierarchical (HDATA) tables when using a CDSC that supports only a VDATA view, and to query a VDATA table when using a CDSC that supports only an HDATA view. In this situation, the UNICOM Intelligence OLE DB Provider (and other UNICOM Intelligence components, such as the Weight Component) will automatically invoke the Table Services DSC to provide the missing tables.