Database Reference
In-Depth Information
Figure 21-8.
Pessimistic locking behavior: Step 1
When the first session commits the transaction, the exclusive (X) lock would be released. At this point, the row would
have a Color value updated by the first session so that the second session updates two rows rather than one, as shown in
Figure
21-9
. In the end, both rows in the table will be either in Black or White depending on which session acquires the lock first.
Figure 21-9.
Pessimistic locking behavior: Step 2
