This is a living document that is developed incrementally
and iteratively in parallel with other work products.
Different parts of this document are due at different
times (i.e., during different phases).
Some parts of this document are mandatory and some parts
are optional.
Anything that holds data used for or within the
application that needs to be persisted should be documented
including flat files, registry entries, and others.
During the Construction Phase, this document will
typically require iteration as new information and/or
software and hardware changes occur.
The data dictionary and the architecture documents will
typically be iterated in parallel because database
requirements affect the architecture and the architecture
impacts operational and quality capabilities of the
database.
The data dictionary should reference the relevant
documentation of any COTS database or package including a
database for the detailed documentation on the installed DB
structures. Furthermore, the data dictionary should document,
in a detailed manner, any changes made to those structures to
support the operational or quality requirements of the
application.
Where changes are made to data structures of a COTS
database, it is mandatory that these changes be documented in
the data dictionary.
The maintenance, backup, and disaster recovery sections
of the data dictionary are not completely necessary in IT
environments where the client has a formal database
management competency and will take on full responsibility
for the management of the database using management tools
already in place. In such a case, it should be generally
documented that the client has these tools already in their
environment and will utilize them in the operational
management of the database according to their own
guidelines.
A separate data dictionary is not required for each
persistent data store. However, DDDs may be desirable in some
very large implementations where the ongoing maintenance of
the database will be handled by more than one functional IT
group.
