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examples/version/README.md

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+# [Optimistic Lock](https://en.wikipedia.org/wiki/Optimistic_concurrency_control)
+
+In this example, we implement an optimistic locking mechanism using the technique mentioned in 
+[Ent Blog](https://entgo.io/blog/2021/07/22/database-locking-techniques-with-ent/).
+
+The idea is to add to our schema a `version` field that holds the Unix time of when the latest update occurred.
+When an `Update` operation is executed, the hook updates the `version` field with the new value and adds a predicate
+to verify that the `version` wasn't updated by another process/transaction during the mutation.
+
+An error is returned if the versions are mismatched, and the user should reload the entity and retry the mutation.
+
+### Generate Assets
+
+```console
+go generate ./...
+```
+
+### Run Example
+
+```console
+go test
+```