Examine these entries from the general query log: All UPDATE statements reference existing rows. Which describes the outcome of the sequence of statements?
A.
Connection 24 experiences a lock wait timeout.
B.
Connection 25 experiences a lock wait timeout.
C.
A deadlock occurs immediately.
D.
All statements execute without error.
E.
A deadlock occurs after innodb_lock_wait_timeout seconds.
root@localhost[world]> update t2 set val=42 where id =3805;
ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| innodb_lock_wait_timeout | 900 |
+--------------------------+-------+
correction, 24 and 25 hit the same id, an started a transaction. B and C are correct except b is NOT correct if 24 commits before timeout. So C happens. And C happens because the updates happen BEFORE 24 commits.
I see I didn't say the answer. No commit is ever executed, so the transactions are in limbo. So E is the correct answer. Eventually a timeout will occur. Auto commit does not matter when you begin a transaction. Both connections hit the same row, and are not committed, so there are lock.
Auto-commit not been disabled hence it should be able to execute all
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