Can I create a customized schema subset?

Since the full GJXDM and NIEM schemas include components that are optional and over-inclusive, users have the ability to retrieve only those components from the data dictionaries that they need. Many users will not want every element to be able to occur repeatedly. Furthermore, it is unlikely that a user will need to use the entire contents of the full schemas. This is the basic idea behind schema subsets—to provide smaller schemas that define only those components from the dictionary that the user wants to include.

The full GJXDM or NIEM schemas can be used, but it is not necessary to do so. Smaller schema subsets can be more manageable than the full schemas and will usually permit more rapid validation of document instances. The overriding rule for using GJXDM or NIEM schema subsets is as follows: Document instances that validate to the schema subset will validate to the full GJXDM or NIEM.

The Schema Subset Generation Tool (SSGT) produces compliant schema subsets. It is available at the following locations:

NIEM SSGT: http://niem.gtri.gatech.edu/niemtools/ssgt/SSGT-Search.iepd