First, I pull some records:

SELECT *;
  FROM MyTable;
  WHERE SomeValue = 1;
  INTO CURSOR MyCursor

Next, update or delete from original table:

  UPDATE MyTable;
    SET SomeField = SomeValue;
    WHERE Id IN;
     (SELECT Id FROM MyCursor)

  ** OR

  DELETE FROM MyTable;
    WHERE Id IN;
     (SELECT Id FROM MyCursor)

These 2 SQL's are very slow. How can I do thses using joins?

Thanks