Question

I am facing issue deleting set of records from a table named links_data because of huge set of data to be deleted and the Oracle DB ran out of temp space.

For the same with little knowledge of mine on Stored Procedure I wrote the below code.
But the Stored Procedure looks to be running slow as well.

The scenario is that I need to delete the rows from links_data table where the nm_folder column in links_data table has foreign key relation with link_folders table. nm_folder in link_folders table is the primary key and I intend to delete 10000 records at a time and commit and then again delete 10000 records and commit.

Kindly anyone please help me optimize this query. Thanks & Regards,

Declare

Type ty_link_floder is table of number;

tble_id_folder ty_link_floder;

    Cursor c_data is
    select id_folder from link_folders where nm_folder='User Hotlist';

    Begin
    OPEN c_data;

      LOOP
        FETCH c_data
        BULK COLLECT INTO tble_id_folder LIMIT 10000;
        EXIT WHEN tble_id_folder.count = 0;
                    FORALL i IN tble_id_folder.first .. tble_id_folder.last
        DELETE FROM links_data
        WHERE id_folder = tble_id_folder(i);
        COMMIT;

        -- Process contents of collection here.

        DBMS_OUTPUT.put_line(tble_id_folder.count || ' rows deleted from links_data table so far');
        tble_id_folder.delete;
      END LOOP;
      CLOSE c_data;
    Exception
     When others Then
      Commit;
      Raise;
    End;

Answer 1

I’d try it first in one SQL statement:

DELETE FROM links_data d
 WHERE id_folder IN (
       SELECT id_folder FROM links_folder WHERE nm_folder='User Hotlist');

If you run out of temp space and the DBAs cannot set up additional temp space, the best way is to recreate the table without the rows that should be deleted:

CREATE TABLE links_data_tmp AS
SELECT * FROM links_data d
 WHERE id_folder NOT IN (
       SELECT id_folder FROM links_folder WHERE nm_folder='User Hotlist');

After that, you need to rebuild all indexes and constraints on links_data_tmp that have been defined on links_data. Then you can swap the temporary table with the real one:

RENAME links_data TO links_data_old;
RENAME links_data_tmp TO links_data;

Don’t forget to reapply all the privileges, too.