Consistency Check of the Source Model

BACKGROUND PURPOSE:
‎Data Modeling, Data Integration (ETL/DI), Business Intelligence (BI) and other design tools supported by MIMB may not always save models which are valid. Indeed, some of these models may still be under development (not yet completed), or the model validation may be a separate step (design tool menu entry, separate tool, or part of the model publication). Therefore, MIMB import bridges may be dealing with semantically incorrect or incomplete models which the MIR repository can save, but they may break the export bridges. Having a centralized model validation (or consistency check) between the import and export phases allows to continuously improve the consistency check algorithms and avoids having each export bridge retest for the same model validity issues.

INPUT PARAMETERS:
‎The user has the choice of 3 levels of consistency check:

• "No Consistency Check": If the user purposely decides to turn off all consistency check (e.g. when the tool is not available to fix the source model), then the imported model may break the export bridge, or produce an invalid model that may break the target tool. MITI assumes no responsibility when consistency check is turned off.
• "Basic Consistency Check": This level corresponds all minimal consistency checks required to export, including (but not limited to) the detection of disconnected relationships, foreign keys not connected to any primary or alternate key, etc.
  ‎Note 1: the source model may pass the model validation provided by the original tool, but still may fail the basic consistency check which may include more substantial testing required by the target tools.
  ‎Note 2: the basic consistency check may be more rigorous than needed by the export bridge or target technology/tool that will be used. In such case, some of the warnings or errors can be ignored.
  ‎Note 3: the basic consistency may not be complete enough to catch all the model validation tests of the target tools. Therefore, the user should still run any model validation or consistency check available in the target technology/tool.
• "Detailed Consistency Check": This level includes a more verbose version of the above basic consistency checks, plus more advanced semantic checks specific to the technology of the source model: RDBMS (e.g. attributes of a PK cannot have a null value), ETL/DI metamodels, or ROLAP/MOLAP BI metamodels (e.g. a hierarchy must have a root). This level is sometimes used as a substitute to the lack of model validation capabilities in the original tool, but is not required to use the MIMB export bridges.

OUTPUT RESULTS:
‎Consistency checks will report (in the log) "WARNINGS" on the source model, or "ERRORS" that are fatal and will prevent the export to any tool. The solution is to fix the original model, and then import it again.