I wanted to know, how we could disable the write lock, in case the application shards the writes per thread ? I guess that would imply to have one btree per thread, isn't it ?

We could as well use as many DB as threads (at the cost of also sharding the reads) ?

In that case, how can I disable the write lock ?

Would commenting LOCK_MUTEX_W() & UNLOCK_MUTEX_W() make the trick ?