TS/MP Pathsend and Server Programming Manual (H06.05+, J06.03+)

relationships between each of the files in the database and then normalize your database files.
To normalize files is to ensure, at a minimum, that:
• There are no repeating fields.
• Data is dependent on the entire key (a unique element) of a field.
• Data is dependent on nothing but the key.
Physical Design
You undertake the physical design of your database by selecting the appropriate file types and
record keys for each of the files in the database. Whether you are using the SQL/MP software or
the Enscribe software as your database management system (DBMS), these file types can be
classified as key-sequenced, relative, entry-sequenced, or unstructured:
Each record in the file has a primary key and up to 255 alternate keys. The primary key
is a field or combination of fields within the record.
Key-sequenced
Each record in the file has a unique record number, which is the primary key, and can
have up to 255 alternate keys. The record number is a unique value that corresponds to
the physical location of the record within the file.
Relative
Each record in the file has a unique record number and can have up to 255 alternate
keys. The record number corresponds to the order in which a record is stored in the file.
The primary key is the relative byte address of the record.
Entry-sequenced
Each record in the file has a unique record number that can be used as the primary key.
Alternate keys are not supported.
Unstructured
Although the file type you choose depends on your application requirements, generally you should
choose key-sequenced files for a database that will be accessed and maintained by a Pathway
application. Key-sequenced files provide more flexibility than the other file types.
Database Managers
Databases supporting Pathway applications can run under either the SQL/MP relational database
management system (RDBMS) or the Enscribe database record manager. Both of these products
support the creation and use of large databases capable of operating in local or distributed systems.
The SQL/MP product is both a DBMS for production environments and an RDBMS for
decision-making in an information-center environment. The SQL/MP product allows you to think
about and represent files in the database as a collection of similarly structured lists. For more
information about designing SQL/MP databases, refer to the HP NonStop SQL/MP Reference
Manual.
The Enscribe database record manager provides a record-at-a-time interface between Pathway
servers and your database. For more information about designing Enscribe databases, refer to the
Enscribe Programmer’s Guide.
Remote Duplicate Database Facility (RDF)
If disaster recovery of your database is important, the Remote Duplicate Database Facility (RDF)
is available to maintain a copy of the database on a remote system. The RDF product monitors
database updates audited by the TMF subsystem and applies those updates to the remote copy of
the database. For more information about the RDF product, refer to the Remote Duplicate Database
Facility (RDF) System Management Manual.
Designing the Database 35