TS/MP Pathsend and Server Programming Manual (G06.24+, H06.03+)

Designing Your Application

NonStop TS/MP Pathsend and Server Programming Manual–132500

2-10

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

NonStop 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:

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 NonStop SQL/MP

relational database management system 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 NonStop SQL/MP (Structured Query Language/MP) product is both a database

management system (DBMS) for production environments and a relational database

management system (RDBMS) for decision-making in an information-center

environment. The NonStop 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 NonStop SQL/MP databases, refer to the 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.

Key-sequenced 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.

Relative 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.

Entry-sequenced 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.

Unstructured Each record in the file has a unique record number that can be used

as the primary key. Alternate keys are not supported.