DBCHME - Teradata Tools and Utilities

Teradata® Call-Level Interface Version 2 Reference for Mainframe-Attached Systems

Teradata Tools and Utilities
Release Number
June 2021
English (United States)
Last Update
Product Category
Teradata Tools and Utilities


Called by the application to establish a master event in place of individual session events.


This routine is called with the following parameters, stylistically presented (the actual syntax varies according to the programming language being used):


In high-level languages, the details of the parameter list are handled by the compiler. For Assembler, the parameter list consists of contiguous 4 byte entries, each containing the 31 bit address of a parameter. The last address has the first bit set to one to indicate the end of the list.

The parameters for this routine are:

Argument Content
ReturnCode A 4 byte unsigned integer field into which the return code will be placed by CLIv2.
ContextArea A 4 byte unsigned integer field for internal use by CLIv2.
MasterECB When defining a master event (DBCHMEP function code 1), the area allocated by the application for use as the master ECB.

When deleting a master event (DBCHMEP function code 2), this parameter must be present but is not used by DBCHME.

FunctionCode The DBCHMEP area.

Usage Notes

  • Set Wait-for-response to N.
  • DBCHME may only be used when no sessions exist; that is, either before any session has been connected or after all sessions have been disconnected.
  • After the call, the return code variable contains a return code.
  • After the call, CLIv2 changes ContextArea for its own purposes.

For more information on ECBs, see IBM documentation.

Master Event Parameters (MEP)

The following table defines the DBCHMEP area. The field is set by the application.

The field names in all languages are the same, except that the C field names are case-sensitive.

Field Name Offset Length Description
MEPFUNC (mepFunc) 00 4 Unsigned numeric function to be performed.

Valid function codes and their descriptions are listed in the table following this table.


In the MEPFUNC field, the following are valid function codes:

Function Code Name Mnemonic for All Languages, Including C Description
1 Define MEPFDEF Define a master event.
2 Delete MEPFDEL Delete a master event.