Auto-sharding feature

[oleiade]

Best use case of Elevator would be to shard different databases over different physical disk to reduce the disk seeks footprint.

Bioql does shard its datasets over multiple disk. It gave me the idea linked to that Elevator should be able to auto-shard a given db over multiple disks automaticaly.

Could be configurable via config file.
elevator.conf example:

    [shard-1]
    disk=/var/disk1

    [shard-2]
    disk=/var/disk2

    ...