DBIx::Class onle allows joins for prefetches.
But sometimes you can't use JOIN for prefetch.
E.g. for prefetching many related objects to resultset with paging.

Also you can use this module to create cross-database prefetches.

This module provides other logic for prefetching data to resultsets.

WWW: https://metacpan.org/release/DBIx-Class-CustomPrefetch