> Imagine if SELECT field1, field2 FROM my_table was faster than SELECT field2, field1 FROM my_table.

possibly it might not be smart enough to reorder an index on (field1, field2), or it had some weird internal constraint on tuple ordering, or it was simply different enough to go down a different query plan sometimes, or maybe there’s something around the actual physical ordering on disk?

but yeah postgres and SQLite are modern marvels that we take for granted… myISAM was not a good time, or at least people tended to violate the correctness/visibility rules it promised (iirc) or something like that. The fact that you can just open up a stable, well-tested sql instance that runs against disk, or drop Postgres into most transactional use-cases, and generally not have to worry about unduly fighting the DB itself, is underappreciated.