It's hard to say whether one would generally be a bigger gain than another without experimenting. We chose to focus on just execution because it was a relativel

It's hard to say whether one would generally be a bigger gain than another without experimenting. We chose to focus on just execution because it was a relatively smaller project (with less side-effects) that still promised a large performance improvement. In the future, we might consider keeping data in columnar format on learner replicas to offer even better performance for users that would like to run OLAP-style queries on slightly stale data, but this would be a larger project.