Move large data between tables in oracle with bulk insert - sql

Question

I want to move 1 million rows of data to another table. Im using query:
insert into Table1
select * from Table2;
in my PL/SQL function. But this way is too slow.
How can I do this with Bulk Insert method?
Source and destination table has same structure.
Tables have hash partition and 1 index.

Answer 1

Forget about bulk insert. Because the insert into select is the best bulk you can load.
The fastest would be to disable the indexes (mark them unusable) and do this in a SINGLE
insert:
insert /*+ append */ into TARGET
select COLS
from SOURCE;
commit;
and rebuild the indexes using UNRECOVERABLE (and maybe even parallel).
PS: If the table is partitioned (Both source and target, you can even use parallel inserts)
FOLLOW UP:
Check the performance of the below select
SELECT /*+ PARALLEL(A 4)
USE_HASH(A) ORDERED */
YOUR_COLS
FROM
YOUR_TABLE A
WHERE
ALL_CONDITIONS;
If faster then
INSERT /*+ APPEND */
INTO
TARGET
SELECT /*+ PARALLEL(A 4)
USE_HASH(A) ORDERED */
YOUR_COLS
FROM
YOUR_TABLE A
WHERE
ALL_CONDITIONS;

Answer 2

USING Bulk Collect
Converting to collections and bulk processing can increase the volume and complexity of your code. If you need a serious boost in performance, however, that increase is well-justified.
Collections, an evolution of PL/SQL tables that allows us to manipulate many variables at once, as a unit. Collections, coupled with two new features introduced with Oracle 8i, BULK_COLLECT and FORALL, can dramatically increase the performance of data manipulation code within PL/SQL.
CREATE OR REPLACE PROCEDURE test_proc (p_array_size IN PLS_INTEGER DEFAULT 100)
IS
TYPE ARRAY IS TABLE OF all_objects%ROWTYPE;
l_data ARRAY;
CURSOR c IS SELECT * FROM all_objects;
BEGIN
OPEN c;
LOOP
FETCH c BULK COLLECT INTO l_data LIMIT p_array_size;
FORALL i IN 1..l_data.COUNT
INSERT INTO t1 VALUES l_data(i);
EXIT WHEN c%NOTFOUND;
END LOOP;
CLOSE c;
END test_proc;

Answer 3

this procedure created by rohit sahani......
using bulk collect i create this procedure
in this procedure i also did update and insert in table and
in this procedure i did collect data in bulk and then update in salary with the use of forall statement .
CREATE OR REPLACE PROCEDURE sam_proc_1(l_salary NUMBER)
IS
l_address VARCHAR(100) := 'karnatka';
a_address VARCHAR(100) := 'bihar';
c_limit PLS_INTEGER := 100;
TYPE employee_ids_t IS TABLE OF emp.emp_id%TYPE;
l_employee_ids employee_ids_t;
CURSOR employees_cur IS SELECT emp_id FROM emp;
-- CURSOR CUR1 IS SELECT EMP_ID, FNAME, ADDRESS FROM EMP;
BEGIN
OPEN employees_cur;
LOOP
FETCH employees_cur BULK COLLECT INTO l_employee_ids LIMIT c_limit;
EXIT WHEN l_employee_ids.COUNT = 0;
-----here start updating
FORALL indx IN 1 .. l_employee_ids.COUNT SAVE EXCEPTIONS
UPDATE emp a
SET a.salary = a.salary + l_salary
WHERE a.emp_id = l_employee_ids(indx);
commit;
END LOOP;
-----------
BEGIN
UPDATE emp v
SET v.address = l_address
WHERE v.address = a_address;
COMMIT;
EXCEPTION WHEN
OTHERS THEN
RAISE_APPLICATION_ERROR(-20001,'An error encountered while updating in address - '
||SQLCODE||' -ERROR- '||SQLERRM);
END;
---------
BEGIN
FOR I IN ( SELECT EMP_ID, FNAME, ADDRESS FROM EMP)
LOOP
INSERT INTO students
( stu_id, stu_name, stu_address)
VALUES
(i.emp_id, i.fname, i.address);
END LOOP;
COMMIT;
EXCEPTION WHEN
OTHERS THEN
RAISE_APPLICATION_ERROR(-20001,'An error encountered while inserting - '
||SQLCODE||' -ERROR- '||SQLERRM);
END;
------------
EXCEPTION
WHEN OTHERS
THEN
IF SQLCODE = -24381
THEN
FOR indx IN 1 .. SQL%BULK_EXCEPTIONS.COUNT
LOOP
-- Caputring errors occured during update
DBMS_OUTPUT.put_line( SQL%BULK_EXCEPTIONS (indx).ERROR_INDEX
||','||
SQL%BULK_EXCEPTIONS (indx).ERROR_CODE);
--<You can inset the error records to a table here>
END LOOP;
ELSE
RAISE;
END IF;
END sam_proc_1;
-----END PROCEDURE;c