Architectural Principles Meta Tables and Meta Data
There is a growing requirement to capture general information about the structure of the data model and the implementation of global issues such as UOM and coordinates. The proposed guidelines and the implementation of these guidelines provide a start that is expected to evolve in future releases of PPDM.
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Objectives
To define a set of Meta tables to hold information about the structure of the PPDM data model that includes major components such as tables, columns, constraints, domains, and units of measure.
Usage
Data Model Documentation
Capture full names of table or columns (entity or attributes). Table and column names may be abbreviated to meet naming conventions or DBMS requirements. This provides a place for the complete name. Provide domains and identify to which domain a column belongs Provide common UOM, data type, data widths, value constraints.
Identify columns that are grouped
Groups of columns, such as those sharing common data domain information (depths), those used by an application or those affected by a business process can be defined to help manage the model and its usage.
Document user extensions
Provide a central repository for local extensions and/or subsets. This facilitates local managing of migration issues, as well as installation of PPDM-compliant systems.
Data management functions
The data management work group has provided a substantial set of extensions to the PPDM meta model that support improved data management practices. Refer to the work group documentation for details.
