This chapter includes the following sections:
User exits extend and customize the functionality of the Extract and Replicat processing by calling COBOL, TAL or C routines from the Extract or Replicat parameter files. At different points during processing you can invoke custom COBOL, TAL or C routines to perform specialized functions.
Reference Guide for HP NonStop (Guardian) supplies:
Function parameters for accepting and processing different events and information from Extract or Replicat.
Calling environment functions, in TAL, C and COBOL, for retrieving context information from Extract or Replicat.
Two example user exits are supplied with the installation code: DEMOXCOB
(written in COBOL) and DEMOXC
(written in C). You can use these exits as a sample to help plan your own user exit routines. Two blank user exit templates are also included: USEREXC
for C
and USEREXT
for TAL
. You can use these to start coding your routines. There is no sample for TAL
and no template for COBOL
.
Note:
User exits may be used for many kinds of routines; however, you should avoid controlling transaction commits with custom user exit logic. This could interfere with Oracle GoldenGate checkpoint processing, which facilitates troubleshooting and protects you in case of system failure.