Re: pg_upgrade does not upgrade pg_stat_statements properly

To a certain extent it is beyond pg_upgrade's purview to care about extension explicitly - it considers them "data" on the database side and copies over the schema and, within reason, punts on the filesystem by saying "ensure that the existing versions of your extensions in the old cluster can correctly run in the new cluster" (which basically just takes a simple file copy/install and the assumption you are upgrading to a server version that is supported by the extension in question - also a reasonable requirement).  In short, I don't have a suggestion on how to improve that and don't really consider it a terrible flaw in pg_upgrade.

I'll readily admit that I lack sufficient knowledge here to make such suggestions as I don't hold any optionions that things are "quite terrible" and haven't been presented with concrete problems to consider alternatives for.

David J.