tree ea8d7ea43b46c6afeab26b21b0fe6bdc05327582
parent ce062ba29edc39563a2ee87a4a1205056426a21c
author Yingyi Bu <yingyi@couchbase.com> 1496426811 -0700
committer Yingyi Bu <buyingyi@gmail.com> 1496541826 -0700

Remove default node group.

In this way, CREATE DATASET statement can adjust to dynamic
cluster topology.

When we create a dataset:
- if the node group name is not given, we create a new node group
  using all currently available nodes;
- if the node group name is give, we use the given node group for
  the dataset.

When we drop a dataset:
- if no other dataset depends on the node group of the dataset to
  be dropped, we also drop the node group.

Change-Id: If68dc6a7c1270ab1f5049c9334e3318425fd8287
Reviewed-on: https://asterix-gerrit.ics.uci.edu/1799
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
BAD: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Michael Blow <mblow@apache.org>