Architectural Principles Recursive Relationships
Recursive relationships, which allow entries in a PPDM tables to refer to other entries in the same table, occur in two forms:
1. Recursive relationships (Pig’s ears) - these relationships are stored in the parent table. For example, the WELL table contains a recursive reference to PARENT_WELL
2. Breakout tables - these relationships are stored in a separate table, with two relationships / constraints to the same parent table. These relationships may be either 1:1 or 1:m - the implementation is the same.
Each of these constructs creates challenges with the insert process, as it may be necessary to first create the parent row of data, and then update the necessary child rows.
This problem is evident between the tables R_SOURCE and R_PPDM_ROW_QUALITY. Special care must be taken to ensure that these tables are loaded correctly.
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- 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
