Optimistic lock pessimistic lock applicable scenario

From the attitude towards the lock, if the lock , Lock can be divided into optimistic lock and pessimistic lock , It can also be seen from the name that these two kinds of locks are treated in two ways Thinking mode of data concurrency . It should be noted that , Optimism and pessimism are not locks , It's locked design idea .
From the design ideas of these two kinds of locks , Let's summarize the applicable scenarios of optimistic lock and pessimistic lock ：
        1. Optimism lock fit There are many reading operations Scene , Relatively speaking, there are fewer operations to write . Its advantage lies in Program realization , There is no deadlock problem , But the applicable scenario will also be relatively optimistic , Because it can't stop database operations other than programs .
        2. Pessimistic locking fit There are many writing operations Scene , Because the write operation has Exclusivity . Adopt pessimistic lock mode , You can prevent other transactions from operating on the data at the database level , prevent read - Write and Write - Write The conflict of .