This point was bugging me for too long. Collections used to be built with hydrated objects using a fetch_all. This caused very high memory consumption and low performances. It has been replaced using a PDO scrolling iterator. New collection system now hydrates objects on demand from the PDO statement. I did quick benchmarks on my small laptop with 100k records. It takes less than 2 minutes to hydrate and display everything with the old and new system but the new collection system uses 20Mbytes of RAM where the old one uses 200 ! This is a critical improvement in a web production environment. I want to do a bit more testing before going for another beta.