Hi Team,

Currently, when we show the collection stats we show the following values (among many others, of course):

• https://www.mongodb.com/docs/manual/reference/command/collStats/#mongodb-data-collStats.storageSize
• https://www.mongodb.com/docs/manual/reference/command/collStats/#mongodb-data-collStats.freeStorageSize
• https://www.mongodb.com/docs/manual/reference/command/collStats/#mongodb-data-collStats.totalIndexSize
• https://www.mongodb.com/docs/manual/reference/command/collStats/#mongodb-data-collStats.totalSize

Similarly to what we show in the database stats, it would be helpful if we added the following totals:

• totalIndexFreeStorageSize: sum of the free (re-usable) space for all indexes on the collection.
• totalFreeStorageSize: sum of the free (re-usable) space for all indexes on the collection + the collection itself.

Since we already show totals for indexes (totalIndexSize and totalSize) I assume this won't result in any meaningful extra work that might hurt performance but that's an aspect that should be considered as deployments with many indexes for a collection might be affected if meaningful additional work is needed to add the proposed totals. If that's the case, we could safeguard showing these totals under a specific option for the collection stats command.

This doesn't affect a specific version, it's something that it would be good to consider for all of them as long as back-porting is possible.

Regards
Diego