How does index locking resolve the phantom problem? What is a predicate lock? Prove that the basic two-phase locking protocol guarantees conflict serializability of schedules. (Hint: Show that, if...

How does index locking resolve the phantom problem?

What is a predicate lock?

Prove that the basic two-phase locking protocol guarantees conflict serializability

of schedules. (Hint: Show that, if a serializability graph for a schedule has a cycle,

then at least one of the transactions participating in the schedule does not obey

the two-phase locking protocol.)