Architectural Principles NULL Data
Data values that are unknown at load time should present as few problems to users of the data model as possible. Consideration must be given to the international composition of the membership, and the variability of data availability and business processes this implies.
Guidelines
1. All components of the Primary Key are mandatory. During design, care must be taken to ensure that the values of all components can be determined at load time.
2. All other columns in a table must be optional. User sites should enforce optionality through use of procedures or triggers.
3. The meaning of a NULL value should be considered during design, and requirements accommodated in the structure.
4. The PPDM Meta model may be used to fully describe the history of columns that are NULL, using the table PPDM_AUDIT_HISTORY. This table can be used to capture information about how information was searched and quality controlled.
Go to
- Architectural Principles NULL Data
- Architectural Principles Dates
- Architectural Principles Versioning
- Architectural Principles Vertical Tables
- Architectural Principles Sequence Control
- Architectural Principles Economics and Financial
- Architectural Principles Column Precision
- Architectural Principles Column Field Type
- Architectural Principles Standardized Columns
- Architectural Principles SQL View Definitions
- Architectural Principles Other SQL Definitions
