I'm working on a new TDM column map exit routine written in C++/C for an installation of distributed Optim TDM, based on a codebase that was written for us several years ago by an IBM consultant.  I have only a rough passing knowledge of C++ so I am kind of hacking my way through this code.  Managed .NET C# is much more my forte.

The exit routine will process an XML document stored as a clob within a SQL Server varchar(MAX) column, using ODPP to mask specific nodes within the XML doc. I actually have the exit working as intended, with one problem.

My DLL crashes when trying to process rows where the clob size is > 400,000 bytes. I have a hard-coded limit so that my exit immediately bypasses rows where this clob size is too large; this limit-check was carried over from the older codebase I mentioned earlier. When I remove the limit check or increase the limit above 400,000 my DLL crashes; when I keep the limit at 400,000 it runs successfully but I reject/bypass about half the rows in the source table. It is a requirement for this particular application that I keep and process all source rows.

We are running distributed TDM v11.3 on a Windows server. My exit code is using the various standard ODPP libraries, header files, etc. from our Optim installation. The farthest I can trace the problem to is struct s_PST_CMExitParm function pPSTGetLOBSegment, defined in PSTCMXIT.H. I'm passing in 400000 as the 3rd input parameter for the 'Length of the LOB data segment to be returned'.

Other than the pPSTGetLOBSegment input parameter for LOB length, I'm not seeing anything that I can change to increase the allowable size of the clob; no switch, config setting, etc.

Any guidance, tips, suggestions, etc would be much appreciated.  Thanks.


Snippet of s_PST_CMExitParm from PSTCMXIT.H:
  /* The following function may be used to get substrings from a LOB
     source column. */
  short(*pPSTGetLOBSegment)(short,    /* Col Handle for the Source
                                          LOB Col */
      long,     /* Zero based offset of the
                   1st byte of the LOB data
                   to be returned. */
      long,     /* Length of the LOB data
                   segment to be returned */
      void *,   /* Pointer to the output buffer
                   area. It is assumed this
                   buffer area is at least as
                   long as the requested segment
                   length. */
      long *,   /* Pointer to a return value
                   that will indicate how
                   long the full LOB data is */
      long *,   /* Pointer to a return value
                   that will indicate how
                   many bytes were actually
                   returned. This may be shorter
                   than the requested length
                   if the requested substring
                   exceeds the end LOB data or if
                   a Multi-byte char of NCHAR
                   character would not be fully
                   returned. */
      short *); /* Pointer to a short Indicator
                   variable. After the call, this
                   field will contain -1 if the
                   column is NULL. Otherwise,
                   this field will be zero.
                   This parameter may be NULL */

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Rob Searson
Application Developer
Progressive Insurance
Mayfield Village OH
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