Mongo version very slow

[marjancek]

Testing the CloudStore with Mongo as its storage is much slower than the relational version, suggesting there might be some problems with the data implementation.
At least read-only operations should be faster than with the relational database.

[Ivansek]

@marjancek The Mongo support in CloudStore is in alpha which means that it's only for testing purposes and not ready for production use.