Are buckets persistent?

[Jose_Ramierez (Jose)]

David,

Can you help me reconcile this thread, with what we discussed here:

Are contents of a bucket held in the same shard?

We are evaluating using buckets to keep data by user account in a single bucket (e.g. the bucket becomes the "accountid" container, holding all documents for that account) The question has arisen: If we have a 20 or 100 shard index, will a given bucket always be kept within a single shard? If not, how many shards will it span?

On that thread, it sounded like I could define a bucket up front (for a given account), and then documents added to that bucket would be held together on a single shard.

Please help me understand all the way.

Thanks!