These are as follows:1. Pessimistic Locking: This control strategy must be kept locked for as long as it remains in database memory. One major disadvantage is that it limits or prevents people from modifying the locked data entity. Pessimistic locking attempts to ensure that changes to the database are safe, however this is not always made possible as the number of users and interactions with the database increases, thus significantly slowing down the operation within the database.2. Optimistic blocking: Optimistic blocking does not try to prevent collisions from occurring, however it aims to detect when they will occur and then tries to counteract and resolve any problems that may occur, meaning that these cases can be avoided. Optimistic locking on the other hand can eliminate the problem of waiting for locks to be released, however this will increase the possibility and potential of accidents and collisions occurring while trying to update the