Make a small investigation into the pessimistic locks and optimistic locks of MySQL

There is a lock mechanism in Mysql. It is generally used in multi-user concurrent operations. pessimistic locks can prevent the loss of updates and non-repeated read concurrency problems, but they will affect the concurrency performance. So I 'd like to know if Mysql's pessimistic lock will be used in the project program. Thank you for your reference...

There is a lock mechanism in Mysql. It is generally used in multi-user concurrent operations. pessimistic locks can prevent the loss of updates and non-repeated read concurrency problems, but they will affect the concurrency performance.

So I 'd like to know if Mysql's pessimistic lock will be used in the project program. Thank you for your comments!

Reply content:

There is a lock mechanism in Mysql. It is generally used in multi-user concurrent operations. pessimistic locks can prevent the loss of updates and non-repeated read concurrency problems, but they will affect the concurrency performance.

So I 'd like to know if Mysql's pessimistic lock will be used in the project program. Thank you for your comments!

Are there two obvious differences? Of course, that is what we need.

Pessimistic locks should not prevent loss of updates.
Two users, Zhang San and Li Si, can update the same database record. Assume that the record is (sex, age) = ('male', 25)

Even if the pessimistic lock is used, will the update of age by Li Si be lost?