Appendix C: C Masking Routines for OCI - Technical Description

This appendix provides a technical description of how C masking routines for OCI work.

Oracle OCI extension of Data Express works as a chain of processes that passes information about each targeted column, such as value, type, length, precision, scale and so on. In contrast to ODBC masking routines, C masking routines for OCI are built as separate processes, and are not included in a DLL. Thus, each masking process (masking routine) becomes a part of the main Data Express processing chain, and can use all the information it passes.

Functional Analysis
C masking routines provide additional functionality over ODBC masking routines in that each routine can:
  • Access and use all of the data related to a column
  • Modify data values on the fly
  • Pass all changed data back to Data Express for insertion into the target
Technical Analysis
The Data Express OCI extension uses predefined data structures that hold column information. It also uses functions that read and write the metadata passed to and from each part of the processing chain. We also provide these functions in a library file so that you can use them in your own written routines just as Data Express uses them.