while there is an explicit delineation between the internal `kv` package[1] and ...

while there is an explicit delineation between the internal `kv` package[1] and the overarching `sql` one[2], your specific concern regarding a query optimizer is not strictly an isolated component at this moment in time. query optimizations, last I checked, was not an explicit pre-processing stage but rather done so when constructing the AST representation of the query with each node being an `iterator` as described in the Volcano Evaluation System paper[3]. there was some work underway to move towards an intermediate representation[4] to go through the standard query optimizations, no context into how far along this effort is.