title: hive query to get json keys
body: <p>I have json as below in hive, each json has different keys, I am thinking to get all keys and use get_json_object to get values. So, Is there hive query get json keys out of it? </p>
  
  <pre><code>{
     "ts":"2016-07-27T13:06:18.089-05:00",
     "logVer":1,
     "msg":"123",
     "appData":{
        "appName":"test",
        "action":"SEARCH",
        "members":[
           {
              "id":"999043206",
              "dob":"02/23/1984"
           }
        ],
        "statusCode":200,
        "resultCode":0
     }
  }
  </code></pre>
  
  <p>Thanks</p>