Introduction to Data Management

3 Accessing Databases
With NonStop SQL
15873 Tandem Computers Incorporated 3-1
On a Tandem computer system, an online transaction processing (OLTP) application
is a set of programs that perform OLTP tasks on behalf of the user. An application
normally runs in a PATHWAY operating environment, established either through
PATHMAKER or through PATHWAY itself. The application consists of requester
processes that handle I/O at the terminal or workstation, and server processes that
operate on the database. These processes communicate with each other. They also
interact with other processes supplied by PATHWAY to support the application.
More about the PATHWAY operating environment appears in Sections 5 and 6.
At the core of most applications is the relational database that holds the data they use.
To help you define, maintain, and access information in your database, Tandem offers
the NonStop SQL distributed relational database management system.
NonStop SQL provides many powerful advantages over other database management
systems. You should use it in creating any new databases on your system and in
writing all new applications that access those databases. You should also use it when
creating new data structures in present databases.
Tandem still offers its first generation database management products, based on the
ENSCRIBE record manager, Data Definition Language (DDL), ENABLE program
generator, and ENFORM query language and report generator. However, for
obtaining maximum productivity, ease of use, and functional consistency, the
recommended database management system is NonStop SQL. Programs can mix SQL
statements and ENSCRIBE calls within the same transaction. Thus, you can use
NonStop SQL even in existing programs originally developed for ENSCRIBE record
access.
Features NonStop SQL offers many powerful and convenient features to business
professionals, database managers, and application programmers. These features are
accessible through both a conversational, interactive interface and a programmatic
interface. They are described in the next few pages.
Flexible Data Access NonStop SQL manages relational databases, where data appears in the familiar form
of tables with rows and columns. This format, explained in Section 1, is illustrated
again in Figure 3-1.