Hi  - We are planning on using Cassandra for an IMAP based implementation. There are some questions that we are stuck with –


1)      Each user will have a pre-defined mailbox size (say 10 MB). We need to maintain a field to check if the mail-box size exceeds the predefined size. Will using the counter family be appropriate ?

2)      Also, we need to have retention for only 10 days. After 10 days, the previous days data will be removed. We plan to have TTL defined per message. But if we do that, how does the counter in question 1 get updated with the space cleaned due to deletion ?

3)      Do we NOT have TTL and manage the deletions within the application itself ?