I remember, all the data is fetched first from the database and only then the items for the current page are filtered. So if you have in your database hundreds of thousends of records you'll have all of them in the memory in one huge array only to filter then a few of them.

This is a problem with Class::DBI, not Maypole. Class::DBI::Iterator fetches all the data and stores it as an array, as opposed to wrapping the underlying DBI statement handle.