ITP uses its own database descriptions for database access. The files containing these descriptions are called DIDs (Database Interface Definition). These database descriptions can contain multiple definitions of sets of related data (e.g. a database record) and the information required to retrieve this data. Relationships between these definitions can be defined as well.
Through these definitions ITP models know where the data resides and how to access it.
The DID is in fact an abstract view on a database which can map to database files, external data retrieval programs, XML tags or SQL queries. This mapping can be one-to-one, meaning that the abstract view closely mimics the original database, but it can also be completely different, offering a much more abstract (high-level) view of the database, which simplifies the development of Model Documents (especially when dealing with highly normalized databases).
By mapping the abstract view of the database to external programs, ITP enables the integration of self-written programs into the data retrieval (and therefore document production) logic. It furthermore allows developers to fine-tune the data retrieval process for special purposes, such as highly controlled data retrieval, mixed environment/dbms data retrieval or high-performance data retrieval.
The phase of developing and implementing this abstract view is separated from the creation and execution of models (the document development and usage phase), enabling organizations to control the data that is accessible to documents.
This abstract view can also be modular, so that the DID or parts of the DID can be reused by other collections of documents.
The program which is used to produce DIDs is called the ITP/Software Development Kit (ITP/SDK).
DIDs are created using one of the two ITP/Software Development Kits (ITP/SDK); ITP/SDK MultiPlatform or ITP/SDK AS/400.
The ITP/SDK MultiPlatform is Microsoft Windows based software for the development of ITP Database Interface Definitions. The definitions in the DID link the data fields in the Model Documents to the actual data retrieval implementations. An implementation can take the form of:
Even if several types of database access are combined and used from one ITP model, the Model Document developer will still see one coherent database view.
The ITP/SDK AS/400 is native OS/400 software for the development of ITP Database Interface Definitions (DIDs), which describe DB2/400 database files.
The ITP/SDK AS/400 has -by nature of the AS/400 system - a built-in wizard to automatically generate database definitions based on any existing database file.
The ITP/SDK AS/400 also includes wizards to generate RPG or COBOL program sources to handle the actual database access. To allow an unlimited freedom in retrieving information from the database, developers can modify these program sources.