Decision Stream : Oracle ORA-01502 error while trying to build a job

[thanask]

[PROGRESS - 12:34:21] JobStream 'TestDisbaleIndex' RunId 2
[PROGRESS - 12:34:21] JobStream TestDisbaleIndex '2-Ext_Linse_Sesy'; starting
[PROGRESS - 12:34:22] SQL Node 4 'Del_Linse'; executing (pid 612)
[PROGRESS - 12:34:22] pid 612 SQL Node 4 'Del_Linse'; reported the following:

delete from costos_wtn
where fecha_sistema >= '2006-07-09 00:00:00'
and fecha_sistema <= '2006-07-09 23:59:59'
and ID_Fuente = 'L1'

DS-DBMS-E400: UDA driver reported the following on connection 'CAS':

DMS-E-GENERAL, A general exception has occurred during operation 'execute immedi
ate'.
ORA-01502: index '.' or partition of such index is in unusable state



[PROGRESS - 12:34:22] SQL Node 4 'Del_Linse'; failed
[VARIABLE - 12:34:22] Variable: RESULT = FALSE
[PROGRESS - 12:34:22] Done - 0 00:00:01 elapsed
[PROGRESS - 12:34:22] JobStream 'TestDisbaleIndex' Failed
jobstream -- failed (10-Aug-2006 12:34:22)

I am getting the above error when trying to run a job from decision stream in which I alter the index to unusable and tried to build a node which inserts record into a table. I even changed the Cogdmor.ini file to include the ALTER_SESSION_PARAMETERS=SKIP_UNUSABLE_INDEX=TRUE and ran the job and I still get the same error.

Do I need to start the services after doing the change? If so how to start decision stream alone? I don't want to affect the other Cognos Services running. Also is there a way to achieve the same thing without altering the cogdmor.ini file? Expecting your reply at the earliest.

Thanks and Regards
Kumar