Unistore is used inside TiDB as a replacement for TiKV when running TiDB in a standalone mode (for development and testing purpose), therefore, copr requests will be pushed to unistore in this case.
The current implementation of the copr execution framework on unistore is not ideal, it is neither vectorized nor well-structed.
In this topic, I want to call for help on refactoring it with the execution framework of TiDB. Note the copr framework in unistore already reused the expression calculation framework of TiDB, it won’t be too difficult to adapt the the existing execution framework.
For more information, please refer to https://github.com/pingcap/tidb/issues/26878
And you can reply directly on that issue if you have any questions (I tend to check github more often).