Four merge operators
Wednesday, April 27, 2011
11:46 AM
Four merge operators
clouds <= [[1, "Cirrus"], [2, "Cumulus"]]
Instantly merge the key/value pairs into the clouds array. In other words, invoke strong consistency! 
clouds <~ [[1, "Cirrus"], [2, "Cumulus"]]
Eventually merge the key/value pairs into the clouds array. Might not be done immediately.
clouds <+ small_clouds
Deferred merge: merge the key/value pairs after the RHS has strong consistency!
clouds <- small_clouds
Deferred delete: remove the keys listed
Because we aim for logical monotonicity, 
one can only add instances to tables. 
there is no "delete key". 
to delete something, you have to make a new table. 