First, thanks Michael!
It's nice to see expected results but I still have some
new questions - please help!
1. CREATE TABLE test (x integer, y integer)
2. INSERT INTO test VALUES (1, 1);
INSERT INTO test VALUES (1, 2);
INSERT INTO test VALUES (3, 2);
3. run two session T1 and T2
4. in session T2 run
UPDATE test SET x = 1, y = 2 WHERE x <> 1 OR y <> 2;
5. in session T1 run
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
UPDATE test SET y = 3 WHERE x = 1;
--
-- 1st record will be changed by T2, qual for new record
-- version will be OK, but T1 should be aborted (???)
--
6. in session T2 run
COMMIT;
7. in session T1 run
ROLLBACK; -- just to be sure -:)
8. now in session T2 run
UPDATE test SET x = 2;
9. in session T1 run
SET TRANSACTION ISOLATION LEVEL READ COMMITTED;
UPDATE test SET y = 4 WHERE x = 1 or x = 2;
11. in session T2 run
COMMIT;
12. in session T1 run
SELECT * FROM test; -- results?
^^^^^^^^^^^^^^^^^^
I would like to be sure that T1 will update table...
TIA,
Vadim
