mapcache_seed consumes huge amount of RAM in high zoomlevels

[jendrusk]

I'm assuming that mapcache_seed is generating a list of tiles to be (in my case) deleted, but on higher zoom levels that list is huge, so 8G RAM is not enough to delete worldwide tiles for zoom 7-14. Can't we use some kind of generator instead of generated list? Also - if we don't use bbox filtering we don't need a full list of tiles to be deleted because we're deleting full scope of zoom levels. In case of examptional sqlite settings with every zoom level in separate file that's nothing more than deleting whole file... IMO we don't need a list of tiles to be deleted (processed) if we know that we have to delete all of them in ZL.

It would be great if someone look into that and try to optimize it.