My Datacom Server application is getting -4 SQL return code
(-4 - OVERFLOW TYPE<x> ACTION<ASSIGNMENT/CONVERSION>).
How can I provide information to Support to help diagnose the problem?  

z/OS
WINDOWS 
LINUX

For the SQL -4, turn on the following traces:
   TRACEERR - Calls to MUF
   TRACEEXPR - Expression and data type

CA Datacom Core - 15.1 section “Statistics and Diagnostics Area (PXX) Report” on “COMM ALTER (Modify Error Table)”
https://docops.ca.com/ca-datacom/15-1/en/reference/dbutlty-reference/utility-function-summary/comm-communicate-with-muf/comm-alter-modify-error-table
 
Scroll down in the section to “,TRACE=“  for the SQL trace class-name list of available traces for SQL situations.

Turn on traces.
Example DBUTLTY statements. Supply the Jobname to limit the tracing CA Datacom Server mainframe jobname
  COMM OPTION=ALTER,TRACE=TRACEERR,JOBNAME=jobname
  COMM OPTION=ALTER,TRACE=TRACEEXPR,JOBNAME=jobname

Recreate the -4 situation.

Turn off the traces:
   COMM OPTION=ALTER,TRACE=NONE

Provide Support with the trace outputs (PXXSQLnn SYSOUT) (or DBUTLTY REPORT AREA=PXX,DUMPS=TRACE report if not using SYSOUT).
 

 

For the details for SQL return codes, refer to CA Datacom Messages “SQL Return Codes Quick Reference”
https://docops.ca.com/ca-datacom-messages/en/ca-datacom-db-messages/sql-codes/sql-return-codes-quick-reference

Refer to KB000018269 “How do I use the Multi-User Facility Startup Option called SYSOUT?”
https://comm.support.ca.com/kb/how-do-i-use-the-multiuser-facility-startup-option-called-sysout/kb000018269