Quick Question on Check-pointing and Partition Files

[John Wilson]

Hi,

Ignite documentation states that during check-pointing dirty pages will be
written to partition files. I have two question based on this:


   1. What exactly is a partition file? What determines the number of
   partitions for a Cache?
   2. Are partition files immutable? or do dirty pages that are being
   written during checkpoint overwrite previously existing pages in the
   partition files?

Thanks,
John