Say I have an Entity A and an Entity B, A is a parent of B, that is, many B's can be part of a single A's entity group.
Now, say I put to the HRD a bunch of B's (across many entity groups - i.e. they across many A parents). If I now query for all B's within a single entity group (i.e. the same A parent), am I guaranteed strong consistency? The subtlety here is that although I'm querying over a single entity group the orignal PUT was over multiple entity groups.
Yes - queries over a single entity group (provided you specified an ancestor filter - simply having all the results coincidentally in the same group is not sufficient) are always strongly consistent.