A little investigation into the pessimistic lock and optimistic lock of MySQL

There is a lock mechanism in MySQL, generally used in multi-user concurrent operation, pessimistic lock can prevent the loss of updates and non-repeatable read such concurrency problems, but it can affect concurrency performance.

So want to know everyone in the project program will not use the pessimistic lock of MySQL, welcome to express their views!

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There is a lock mechanism in MySQL, generally used in multi-user concurrent operation, pessimistic lock can prevent the loss of updates and non-repeatable read such concurrency problems, but it can affect concurrency performance.

So want to know everyone in the project program will not use the pessimistic lock of MySQL, welcome to express their views!

Isn't there a clear difference between the two? Of course it's the one that needs it.

Pessimistic locks should not prevent the loss of updates.
Two users Zhang San, John Doe, both of them can update the same database record. Assumption recorded as (sex,age) = (' Male ', 25)

Even with pessimistic locks, John Doe updates to age will be lost?

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