Ask HN: Are any databases implementing own memory paging (swapping)?

The question is - Are (any or all?) database systems engines implementing own memory paging (memory swaping mechanisms) beside just what Operating System is providing so they can still work even when memory available trough OS virtual memory is exhausted? Or in other words - so they could work on data sets far exceeding size of memory that virtual memory can provide? Can you provide examples of database engines that do have such functionality implemented?