Hi,

I have 2 tables on Production CASE and CASE_AUDIT. Table CASE has 13 Million unique Case_IDs.
The ralationship between Case and Case_Audit is based on Case_ID. Case_Audit has 46 Million records and Case_ID in Case_Audit table has a reference from Case table.

I have added a new field say (NCOL VARCHAR(90)) in Case_Audit table and I will make it NOT NULL after updating that field.

Now i want to update that field by a Space eg. ' '. If i fire a normal Update "Update Case_Audit set NCOL=' ';" , It takes around 48 hrs. During the testing of any Solution, I don't want my ROWID to be changed because some of our Reports are based on ROWID. I have followed some approaches, Which r following.

1.	------------------------Bulk Update---------------------------
	drop Sequence CASE_SEQ;
	drop table TEMP_TABLE;
	create sequence CASE_SEQ Minvalue 1 Maxvalue 999999999999999999999999999 Start With 1 			Increment By 1 Cache 100;
	create table TEMP_TABLE NOLOGGING PARALLEL 4 as select Case_SEQ.Nextval Seq_No,CASE_ID from 		CASE;
	
	Declare
		TYPE RC_CASE_TYPE IS TABLE OF CASE.CASE_ID%TYPE;
		v_CASE RC_CASE_TYPE;
		CURSOR c IS SELECT CASE_ID FROM TEMP_TABLE WHERE SEQ_NO >= 1 and SEQ_NO <= 1000000;

	BEGIN
    	OPEN c;
    
    		FETCH c BULK COLLECT INTO v_CASE;

		FORALL i IN 1 .. v_CASE.count() 
		update CASE_AUDIT set NCOL=' ' where CASE_ID=v_CASE(i);

		COMMIT;

	CLOSE c;
END;
/

2.	-----------------------Parallel Update---------------------------
	alter table CASE_AUDIT parallel 4;
	alter session enable parallel dml ; 
	alter session enable parallel query ;

	update /*+ parallel(a,4) */ CASE_AUDIT set NCOL = ' ';

	alter session disable parallel dml ; 
	alter session disable parallel query ; 
	alter table CASE_AUDIT noparallel ;
	/

The Performance of Bulk Update is very bad But Parallel Update has produced some good results. But i want some excellent solution from u. Thanks a Ton!