druid/docs/content/SelectQuery.md

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Select Queries

Select queries return raw Druid rows and support pagination.

 {
   "queryType": "select",
   "dataSource": "wikipedia",
   "dimensions":[],
   "metrics":[],
   "granularity": "all",
   "intervals": [
     "2013-01-01/2013-01-02"
   ],
   "pagingSpec":{"pagingIdentifiers": {}, "threshold":5}
 }

There are several main parts to a select query:

property	description	required?
queryType	This String should always be "select"; this is the first thing Druid looks at to figure out how to interpret the query	yes
dataSource	A String defining the data source to query, very similar to a table in a relational database	yes
intervals	A JSON Object representing ISO-8601 Intervals. This defines the time ranges to run the query over.	yes
dimensions	The list of dimensions to select. If left empty, all dimensions are returned.	no
metrics	The list of metrics to select. If left empty, all metrics are returned.	no
pagingSpec	A JSON object indicating offsets into different scanned segments. Select query results will return a pagingSpec that can be reused for pagination.	yes
context	An additional JSON Object which can be used to specify certain flags.	no

The format of the result is:

 [{
  "timestamp" : "2013-01-01T00:00:00.000Z",
  "result" : {
    "pagingIdentifiers" : {
      "wikipedia_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9" : 4
    },
    "events" : [ {
      "segmentId" : "wikipedia_editstream_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9",
      "offset" : 0,
      "event" : {
        "timestamp" : "2013-01-01T00:00:00.000Z",
        "robot" : "1",
        "namespace" : "article",
        "anonymous" : "0",
        "unpatrolled" : "0",
        "page" : "11._korpus_(NOVJ)",
        "language" : "sl",
        "newpage" : "0",
        "user" : "EmausBot",
        "count" : 1.0,
        "added" : 39.0,
        "delta" : 39.0,
        "variation" : 39.0,
        "deleted" : 0.0
      }
    }, {
      "segmentId" : "wikipedia_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9",
      "offset" : 1,
      "event" : {
        "timestamp" : "2013-01-01T00:00:00.000Z",
        "robot" : "0",
        "namespace" : "article",
        "anonymous" : "0",
        "unpatrolled" : "0",
        "page" : "112_U.S._580",
        "language" : "en",
        "newpage" : "1",
        "user" : "MZMcBride",
        "count" : 1.0,
        "added" : 70.0,
        "delta" : 70.0,
        "variation" : 70.0,
        "deleted" : 0.0
      }
    }, {
      "segmentId" : "wikipedia_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9",
      "offset" : 2,
      "event" : {
        "timestamp" : "2013-01-01T00:00:00.000Z",
        "robot" : "0",
        "namespace" : "article",
        "anonymous" : "0",
        "unpatrolled" : "0",
        "page" : "113_U.S._243",
        "language" : "en",
        "newpage" : "1",
        "user" : "MZMcBride",
        "count" : 1.0,
        "added" : 77.0,
        "delta" : 77.0,
        "variation" : 77.0,
        "deleted" : 0.0
      }
    }, {
      "segmentId" : "wikipedia_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9",
      "offset" : 3,
      "event" : {
        "timestamp" : "2013-01-01T00:00:00.000Z",
        "robot" : "0",
        "namespace" : "article",
        "anonymous" : "0",
        "unpatrolled" : "0",
        "page" : "113_U.S._73",
        "language" : "en",
        "newpage" : "1",
        "user" : "MZMcBride",
        "count" : 1.0,
        "added" : 70.0,
        "delta" : 70.0,
        "variation" : 70.0,
        "deleted" : 0.0
      }
    }, {
      "segmentId" : "wikipedia_2012-12-29T00:00:00.000Z_2013-01-10T08:00:00.000Z_2013-01-10T08:13:47.830Z_v9",
      "offset" : 4,
      "event" : {
        "timestamp" : "2013-01-01T00:00:00.000Z",
        "robot" : "0",
        "namespace" : "article",
        "anonymous" : "0",
        "unpatrolled" : "0",
        "page" : "113_U.S._756",
        "language" : "en",
        "newpage" : "1",
        "user" : "MZMcBride",
        "count" : 1.0,
        "added" : 68.0,
        "delta" : 68.0,
        "variation" : 68.0,
        "deleted" : 0.0
      }
    } ]
  }
} ]

The result returns a global pagingSpec that can be reused for the next select query. The offset will need to be increased by 1 on the client side.