Question

I have Oracle procedure which does the same work as following:

create or replace
PROCEDURE My_TEST_PROCEDURE
(
   cur out sys_refcursor
)
AS
BEGIN
  open cur for
   SELECT * FROM MYTABLE1
   WHERE MYTABLE1.SOMEROWNAME NOT IN 
        (SELECT SOMEROWNAME FROM MYTABLE2);
END My_TEST_PROCEDURE;

But there are a lot of data in this two tables, approximately 300000 rows in each. So it takes a plenty of time to finish. What can I do to decrease that amount of time. I have tried declaring a sys_refcursor and reading data into this cursor as following:

create or replace
PROCEDURE My_TEST_PROCEDURE
(
   cur out sys_refcursor
)
IS
DECLARE EXISTING_ITEMS SYS_REFCURSOR;
BEGIN
  OPEN EXISTING_ITEMS FOR
    SELECT SOMEROWNAME FROM MYTABLE2;
  open cur for
   SELECT * FROM MYTABLE1
   WHERE MYTABLE1.SOMEROWNAME NOT IN 
        EXISTING_ITEMS;
END My_TEST_PROCEDURE;

But this time ORA-00932 error occurs. What can I do?

Thanks in advance.

Answer 1

Use a query with join like below:

SELECT MYTABLE1.* 
FROM   MYTABLE1 
       left join MYTABLE2 
              ON MYTABLE1.SOMEROWNAME = MYTABLE2.SOMEROWNAME 
WHERE  MYTABLE2.SOMEROWNAME IS NULL