[jordanlewis]

We don't have any plans to remove the row-by-row execution engine. Likely, we'll have some analysis during planning that can inform whether to use the row-oriented or column-oriented engine. I think the use cases for the row-oriented engine are exactly what you mention - things like single-row computations or more OLTP queries like point scans, inserts, update etc - where the overhead of setting up the data structures required to use the column-oriented engine would dominate.