I have a saas web application running on gae with multiple namespaces. We also have a staging environment on a different application_id.
Sometimes it would be very useful (for debugging) to be able to replicate production data in the staging environment, for a single namespace.
Appengine already provides an option to backup/restore the whole database (including all namespaces). That doesn't work for us. We have a lot of namespaces, so that would be too slow/expensive.
There's also a Bulk Loader that is able to dump data of a single namespace to a file. There's also a related question about it here on SO: How can I export data from Google App Engine High Replication datastore? I was think maybe there's an easy way to load one such dump file into an existing namespace? I don't know... HELP! :-)