When an application executes the CALL statement, the XDB Server builds a parameter list for the stored procedure, using the parameters and values provided in the statement. The XDB Server obtains information about parameters from the catalog table SYSIBM. SYSPARMS See Defining Stored Procedures under SQL Option for more information. Parameters are defined as one of these types in SYSIBM.ROUTINES:
| IN | Input-only parameters, which provide values to the stored procedure |
| OUT | Output-only parameters, which return values from the stored procedure to the calling program |
| INOUT | Input/output parameters, which provide values to or return values from the stored procedure |
If a stored procedure fails to set one or more of the output-only parameters, the XDB Server does not detect the error in the stored procedure. Instead, the XDB Server returns the output parameters to the calling program, with the values established on entry to the stored procedure.
The XDB Server supports the DB2SQL linkage convention, as cited in detail for the CREATE PROCEDURE command.