# In-Memory Pessimistic Lock

![`smart`](InMemoryPessimisticLocking_aa_003_20220515.png)

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When in-memory pessimistic lock is enabled, the lock information is only stored in memory, not written to disk, and does not need to be written to multiple replicas through Raft, only existing on the Region Leader node. The lock information is written to memory, and the delay is much smaller than writing multiple replicas through Raft.