12 Using xNAL for persistent (database) data storage

xNAL has two main applications:

• name and address data exchange - discussed in Section 11, Using xNAL to exchange information between agencies
• persistent storage - discussed in this section.

xNAL may be used as a reference for building name and address databases.
It represents a highly normalised, hierarchical data model—that may be implemented as a referential data model. Using the xNAL data model as a basis for a relational data model has some benefits as well as drawbacks. It is very important that these are considered before investing in the design and development.

12.1 Benefits and drawbacks of using xNAL as a relational data model

Benefits of using xNAL as a basis for a relational data model include:

• knowledge reuse
• the data model is highly normalised
• the data model is aligned with xNAL
• simplified data insert from xNAL format
• simplified data extraction into xNAL format.

Drawbacks of using xNAL as a basis for a relational data model include:

• the xNAL data model may not be sufficient for some specific business requirements, because some applications may require additional, application-specific data to reside in the same database
• the xNAL data model can be too restrictive.