title: How to get all vector ids from Milvus2.0?
body: <p>I used to use Milvus1.0. And I can get all IDs from Milvus1.0 by using get_collection_stats and list_id_in_segment APIs.</p>
  <p>These days I am trying Milvus2.0. And I also want to get all IDs from Milvus2.0. But I don't find any ways to do it.</p>