Data Item Grouping
All itm_names are organized into groups for selection and presentation. Each group is given a name called grp_name. Grp_names are unique within the application and do not overlap with itm_name.
A group can include other groups or a group can include items. Items in a group must be compatible so that they can form a single table. For example, time series items must use the same calendar if using the same keyset. Items can belong to more than one group. Each group belongs to an entity class that describes the types of entities associated with items in the group. Company level and security level data are examples of entity classes.
Groups can be selected by grp_name, but designated groups can also be selected by a two-letter mnemonic code.