Architectural Principles Arcs
From PPDM Wiki
There are two kinds of arcs – exclusive and non-exclusive.
1. Exclusive arcs - a child table contains FK constraints to a set of parent tables; only one of the parent relationships may be populated for each row in the table.
2. Non-exclusive arcs - a child table contains FK constraints to a set of parent tables; one or more of the parent relationships may be populated for each row in the table.
Guidelines
1. PPDM tables may only contain non-exclusive non-mandatory arcs unless the arc is managed as a super-sub type implementation, as are PDEN and SEIS SET.
2. PPDM tables may use arcs that manage explicit super/sub type implementations in the data model provided that a TYPE column is added to manage the arc.
- The primary key of each table in the super/sub type implementation will include a %_TYPE column that is defined as varchar2(30).
- A check constraint is to be added to the TYPE columns as follows:
- In the super type, the values of the TYPE column name equal the table name of any of the subtypes.
- In each of the sub type tables, the value of the TYPE column name may only be equal to the name of the table in which it is found.
Go to
- Architectural Principles Primary Key Constraints
- Architectural Principles Foreign Key Constraints
- Architectural Principles Check Constraints
- Architectural Principles Indexes
- Architectural Principles Arcs
- Architectural Principles Recursive Relationships
- Architectural Principles Naming Conventions
