Poor Performance using Generic Conectivity for ODBC

Question

Hi my friends.
I have a problem usign Generic Conectivity , I need update 500,000 records in MS SQL Server 2005, I'm using Generic Conectivity for ODBC. In my Oracle Database i have create a DB_LINK called TEST to redirect to MS SQL Server database.
Oracle Database: 10.2.0.4
MS SQL Server version: 2005
The time for update 1,000 records in MS SQL Server using DBMS_HS_PASSTHROUGH is ten minutes. This is a poor performance.
This is de PL/SQL
DECLARE
c INTEGER;
nr INTEGER;
CURSOR c_TEST
IS
SELECT "x", "y"
FROM TEST_cab
WHERE ROWNUM <= 1000
ORDER BY "y";
BEGIN
FOR cur IN c_TEST
LOOP
c := DBMS_HS_PASSTHROUGH.OPEN_CURSOR@TEST;
DBMS_HS_PASSTHROUGH.PARSE@TEST(
c,
'UPDATE sf_TEST_sql
SET observation= ?
WHERE department_id = ?
AND employee_id = ? ');
DBMS_HS_PASSTHROUGH.BIND_VARIABLE@TEST (c, 1, 'S');
DBMS_HS_PASSTHROUGH.BIND_VARIABLE@TEST (c, 2, 'N');
DBMS_HS_PASSTHROUGH.BIND_VARIABLE@TEST (c, 3, 'ELABORADO');
DBMS_HS_PASSTHROUGH.BIND_VARIABLE@TEST (c, 4, 'PENDIENTE');
DBMS_HS_PASSTHROUGH.BIND_VARIABLE@TEST (c, 5, cur."x");
DBMS_HS_PASSTHROUGH.BIND_VARIABLE@TEST (c, 6, cur."y");
nr := DBMS_HS_PASSTHROUGH.EXECUTE_NON_QUERY@TEST (c);
DBMS_HS_PASSTHROUGH.CLOSE_CURSOR@TEST (c);
COMMIT;
END LOOP;
END;
You can help, how better the performance for update 500,000 record by record in MS SQL Server. I need advantages of use Oracle Transparent Gateway for Microsoft SQL Server.
your's can suggest my another solution ?
Thanks.

Answer 1

Hi,
There are no real parameters to tune the gateways. You should turn on gateway debug tracing and check the SQL that is being sent to SQL*Server to make sure is update statements and nothing else.
If this is the case then the time taken will be down to various factors, such as network delays, processing on SQL*Server and so on.
How long does it take to update the same number of records directly on SQL*Server without the Oracle or the gateway involved or if you use another non-Oracle client to do the same updates across a network, if a network is involved ?
It may be possible to improve performance by changing the HS_RPC_FETCH_REBLOCKING parameter, so have a look at this note in My Oracle Support -
Tuning Generic Connectivity And Gateways (Doc ID 230543.1)
Regards,
Mike