ORACLE DATABASE REPLICATION -- ANY APPROACH @ THANKS FOR YOUR HELP

Question

HI ALL,
I am new to Oracle as a developer.Please help me if you find sometime regarding the following requirement .
we are replicating the database (TARGET Database 9.2) with the source database(10G) .
My Idea was to create dblinks for Source DB in Target and use some cursors to populate the data required for destination tables
(Here i have to update the destination table when the records are updated in source DB and insert the records in Destination DB when no record is found in destination).
For this requirement , i am planning to use ORACLE MERGE CONCEPTS.As my destination database is 9.2 and merge with 9.2 is not powerful as per my requirement .
EG :
1)I do not need WHEN MATCHED CLAUSE SOMETIMES )
2)ALSO I NEED MERGE IN TO MULTIPLE DESTINATION TABLES
I came across the following code in one of your posting .If this really works with 10g version .I think i am in the correct path (I can write stored programs in source Database (It is 10g))
IF NOT THIS ....ANY OTHER APPROACH...
drop table external_tbl;
drop table dim1;
drop table dim2;
drop table fact_tbl;
create table external_tbl ( dim1_cd char(1), dim2_cd char(1), qty number );
insert into external_tbl values ( 'A', 'B', 1 );
insert into external_tbl values ( 'B', 'C', 2 );
insert into external_tbl values ( 'A', 'D', 3 );
create table dim1 ( dim1_cd char(1) primary key, dim1_description varchar2(20) );
insert into dim1 values ( 'A', 'At the Earth''s Core');
insert into dim1 values ( 'B', 'Barsoom');
create table dim2 ( dim2_cd char(1) primary key, dim2_description varchar2(20) );
insert into dim2 values ( 'B', 'Buck Rogers');
insert into dim2 values ( 'C', 'Carter, John');
create table fact_tbl ( dim1_cd char(1) references dim1, dim2_cd char(1) references dim2, qty
number )
MERGE ALL
USING(SELECT dim1_cd, dim2_cd, current_qty
FROM external_tbl) b
INTO fact_tbl a
ON ( b.dim1_cd = a.dim1_cd
AND b.dim2_cd = a.dim2_cd)
WHEN NOT MATCHED THEN
INSERT
(dim1_cd, dim2_cd, current_qty)
VALUES
(b.dim1_cd, b.dim2_cd, b.qty)
WHEN MATCHED THEN
UPDATE current_qty
SET qty = b.qty
INTO dim1 d1
ON (b.dim1_cd = d1.dim1_cd)
WHEN NOT MATCHED THEN -- insert a dummy record
INSERT INTO dim1 ( dim1_cd, dim1_description )
VALUES (b.dim1_cd, 'unknown' )
INTO dim2 d2
ON (b.dim1_cd = d2.dim2_cd)
WHEN NOT MATCHED THEN -- insert a dummy record
INSERT INTO dim2 ( dim2_cd, dim2_description )
VALUES (b.dim2_cd, 'unknown' )
and the results to be:
select * from dim2;
D DIM2_DESCRIPTION
B Buck Rogers
C Carter, John
D unknown -- added during the MERGE to maintain ref integrity
select * from fact_tbl;
D D QTY
A B 1
B C 2
-----THANKS FOR READING MY QUESTION

Answer 1

Hi ,
Thanks for the reply....
How can i convert 9i merge to 10g merge (update set column_name = column_name i did not get this )....
Also , My requirement is to update only the updated columns in the source table not the entire row ..I tried like this (but not sure whether it is correct or not)
Compare source to destination and update if not equal
MERGE
INTO red_cust tgt
USING (
SELECT --red_cust_id_seq .nextval  as CUST_ID ,
red_cust_nos(i) as CUST_NO,
red_cust_names(i) as CUST_NAME,
red_cust_inactive_dates(i) as INACTIVE_DATE ,
red_cust_insert_users(i) as INSERT_USER ,
red_cust_insert_dates(i) as INSERT_DATE ,
red_cust_update_users(i) as UPDATE_USER ,
red_cust_update_dates(i) as UPDATE_DATE
FROM master_table
) src
ON ( src.cust_no= tgt.cust_no )
WHEN NOT MATCHED
THEN
INSERT (tgt.CUST_ID ,
tgt.CUST_NO,
tgt.CUST_NAME,
tgt.TAX_EXEMPT_INDIC,
tgt.INACTIVE_DATE,
tgt.INSERT_USER,
tgt.INSERT_DATE
VALUES (src.cust_id
src.cust_no ,
src.CUST_NAME,
src.TAX_EXEMPT_INDIC,
src.INACTIVE_DATE,
src.INSERT_USER,
src.INSERT_DATE
WHEN MATCHED
THEN
UPDATE
set
tgt.cust_name =src.cust_name where tgt.cust_name !=src.cust_name ;
/*Is this correct approach : what i mean by this is :compare src customer_name and target customer name when they are not equal assign it to the destination source name*/
I repeated above for the other columns
tgt.TAX_EXEMPT_INDIC,
tgt.INACTIVE_DATE,
tgt.INSERT_USER,
tgt.INSERT_DATE
After i tried this , i got the computability error again ..as i am merging from 10g to 9i .........(ERROR: Optional where clause in merge is not available in DESTINATION i.e 9i)
If my approach above is correct , is there any alternative for where clause in merge in 9i
I am struck here...Please guide me through the correct path.....
I appreciate your help