Preparing and Executing the Program › Precompiling the Program › About the Precompiler

About the Precompiler

Why You Precompile

SQL is a database sublanguage that is not known to the language compiler. The CA IDMS precompiler:

• Checks the syntax of embedded SQL statements
• Modifies the source code by:
  • Replacing SQL statements in the source program with program language calls to the DBMS
  • Executing precompiler directives
• Stores a relational command module (RCM) for the program if no errors occur in precompiling

When to Precompile

Once you have precompiled a program, you must precompile it again after any changes to either host language or embedded SQL statements. When you precompile a program that was previously precompiled, the DBMS rebuilds the RCM only if one or more SQL statements in the program have changed.

After a program has been precompiled, you can make global changes to the schema-name qualifiers of tables and views in embedded SQL statements when you create the access module. If instead you modify the SQL statements in the source program, you must precompile the program again.

Note: For more information and documentation about the schema-name mapping for tables and views, see Creating the Access Module.

How You Precompile

You precompile the program by submitting a batch job.

For precompiler JCL, see Sample JCL.

You can specify parameters in the precompiler JCL that determine how the precompiler executes.

For documentation of precompiler parameters, see Precompiler Options.

Authorization

To execute the precompiler, you must have:

• The authority to precompile the program if program registration is in effect for the dictionary
• User authority to precompile against the dictionary
• SELECT privilege on tables named in INCLUDE TABLE statements