Hi @aleclofabbro
Welcome to Dgraph Community. Quoting from Dgraph architecture paper
Dgraph’s smallest unit of record is a triple (subject-predicate-object), with each predicate in its entirety forming a shard. In other words, Dgraph logically groups all the triples with the same predicate and considers them one shard. Each shard is then assigned a group (1…N) which can then be served by all the Alphas serving that group.
You can forcefully move one predicate to a group using /moveTablet?tablet=name&group=2. More can be found here. However, during shard rebalance this could change. To save that you can set the rebalance interval flag in Zero to something arbitrarily high, so Zero wouldn’t do tablet moves automatically.