ODBC Server Reference Manual

Architecture Overview

HP NonStop ODBC Server Reference Manual—429151-002

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Background

The following gives background information on the topics of client/server operations,

gateways, and NonStop ODBC Server terminology.

Client/Server Applications

An application program on a NonStop server can use the services of NonStop SQL/MP

by means of an embedded SQL interface. In this type of interface, the NonStop

SQL/MP statements are written in the source program intermixed with the regular

statements of the programming language (COBOL or C, for example). A compiler

translates these embedded statements into calls to the NonStop SQL/MP run-time

routines in the system library. The run-time routines use the SQL file system to access

NonStop SQL/MP tables and other objects.

Embedded SQL is the application program interface (API) for NonStop SQL/MP on

NonStop servers. The API supports the valid syntax of SQL statements and the valid

sequences in which they can be executed. The NonStop SQL programmer also has

knowledge of other issues such as the Guardian ID of the application process, the

default subvolume, security, TS/MP transactions, and the format of the NonStop

SQL/MP catalog tables.

Most DBMS vendors have a different kind of implementation of their SQL product. The

application is typically on a PC or workstation and it makes explicit calls to C functions

in a library. The library connects to a database server program, usually running on

another machine, and sends it the SQL to be processed. In the case of the

Microsoft/Sybase product, the client library is called DBLIB, and the server is called

SQL Server.

Figure 2-2. Application Program Interface for NonStop SQL/MP on a NonStop

Server

Application

Program

NonStop

SQL/MP

Embedded SQL API

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