HOW to USE 'LONG RAW' in Bulk Insertion using OCI

Hi,

    I need to do bulk insertion of LONG RAW data into a table using the OCI.
  To the OCIBindByPos API what should I specify in the field size(value_sz). As different records can have different lenght for this LONG RAW data what value should I provide.

Thanks,
Tuhin

sword OCIBindByPos ( OCIStmt *stmtp,

                     OCIBind      **bindpp,
                     OCIError     *errhp,
                     ub4          position,
                     dvoid        *valuep,
                     sb4          value_sz,
                     ub2          dty,
                     dvoid        *indp,
                     ub2          *alenp,
                     ub2          *rcodep,
                     ub4          maxarr_len,
                     ub4          *curelep, 
                     ub4          mode );