The
lock behavior depends among other things on the type of lock. Tables and rows are locked in a transaction with a defined lock mode (Requesting and Releasing a Lock).The database system differentiates between the following locks:
The following table provides an overview of the possible parallel shared locks (S locks) and exclusive locks (E locks).
A lock collision exists in the cases which are marked with "No"; i.e., after having requested a lock within a transaction, the user must wait for the lock to be released until one of the above situations or one of the situations that are marked with "Yes" in the matrix occurs.