POSC Meta Model Specifications Version 2.3 |
Logical Data Model |
A column_group defines a group of columns that together provide some logical meaning or a physical constraint. For example, if you have two columns that represent a quantity of length, one holding the numeric length value and the other holding the unit of measure that qualifies the numeric value, then these form a logical pair that is expressed with a column_group. Another example of column_group is to define those columns which are used in the construction of an index.
- column_def (M: column_def(column_group))
- One of the columns that makes up this column_group,
- head_col_grp (M: column_group)
- The "head" of this column_group, i.e. the column that is the first one of this group.
- prod_versn (M: prod_versn)
- The production version of the projection run that resulted in this column_group.
- ref_column_grp_kd (M: ref_column_grp)
- The kind of column_group, for example an index, or a projection of a complex attribute.
- column_group_nm (O: string(40))
- The name of this column_group.
Entity projects as table COLUMN_GROUP.
Referenced in Diagrams:
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