I don't know what you're trying to say. PostgreSQL makes no distinction between primary and secondary indexes. MySQL, which only knows clustered indexes (see "U

I don't know what you're trying to say. PostgreSQL makes no distinction between primary and secondary indexes. MySQL, which only knows clustered indexes (see "Unreasonable Defaults" [1]) has to make such a distinction, so that when you use a secondary index it also has to go through the primary index in addition to the secondary index. Also [1] https://use-the-index-luke.com/blog/2014-01/unreasonable-defaults-primary-key-clustering-key https://use-the-index-luke.com/blog/2014-01/unreasonable-def...