SQL/MP Programming Manual for C

ManualsBrandsHP ManualsServerHP NonStop G-Series

151

152

153

154

155

156

157

158

159

160

Explicit Program Compilation

HP NonStop SQL/MP Programming Manual for C—429847-008

6-35

Developing a C Program in a PC Host Environment



secure_err

If the environment variable is set to any of the previous values, these values are used

by the compiler to set the connection mode. If the environment variable is set to any

other value, the compiler returns an error.

If both the -Wsqlconnect option is specified and the environment variable is set, the

value specified in the option overrides the value set in the environment variable.

Developing a C Program in a PC Host

Environment

You can compile SQL/MP applications on the PC by using either the HP Enterprise

Toolkit—NonStop Edition (ETK) or the command-line cross compiler (c89) directly from

the command line in Windows. You must connect to an HP NonStop operating system

host (TNS/R or TNS/E) for SQL compile time operations and to run an application. The

resulting object files can be executed on NonStop TNS/R and TNS/E native systems.

ETK is a GUI-based extension package to the Visual Studio.NET product. You can use

ETK to edit, compile, build, and deploy applications written in C and COBOL with

embedded SQL/MP. You do not have to install Visual Studio.NET or ETK to use the

command-line interface. For more information, see the online help in ETK or the file

“Using Command-Line Cross Compilers” installed with the ETK compiler package. For

command-line help, enter: c89 -Whelp.

Using CONTROL Directives

You can use CONTROL directives with either static or dynamic DML statements.

However, CONTROL directives do not affect DDL statements. The CONTROL

directives and their functions are:

CONTROL EXECUTOR

allows or prohibits parallel evaluation of a query by multiple SQL executors.

Parallel execution can decrease the elapsed time for processing a query.

CONTROL QUERY

controls query execution plans as follows:



Optimization of query response time for returning only the first few rows found

or for returning all rows found



Use of hash join algorithms in execution plans