To prevent concurrent access of records, a transaction requires a prior to data access. key grain timestamp lock

Lock

Explanation:

Locks is a mechanism to avoid the access of records from interacting with one another either in the form of user objects for example tables and/or rows or system objects not cannot be seen by the user such as data shared in memory.

The system (Oracle) obtains all the required locks when executing the transaction request so as to avoid any hassle faced by the user and so that they don't require to be bothered by it. This way the system provides both highest degree of data monitoring with lowest restriction.

Moreover, a fail safe data integrity is provided by the system in case of any failure. This lock can also be done manually by the user.

88 because 4 plus 4 equals 8. 40 plus 40 equals 80. 80 plus 8 equals 88

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