Incorrect unique values from field in elasticsearch

Question

I am trying to get unique values from the field in elastic search. For doing that first of all I did next:

PUT tv-programs/_mapping/text?update_all_types
{
  "properties": {
    "channelName": { 
      "type":     "text",
      "fielddata": true
    }
  }
}

After that I executed this :

GET _search
{
"size": 0,
"aggs" : {
    "channels" : {
        "terms" : { "field" : "channelName" ,
        "size": 1000
        }
    }
}}

And saw next response:

...
"buckets": [
        {
          "key": "tv",
          "doc_count": 4582
        },
        {
          "key": "baby",
          "doc_count": 2424
        },
        {
          "key": "24",
          "doc_count": 1547
        },
        {
          "key": "channel",
          "doc_count": 1192
        },..

The problem is that in original entries there are not 4 different records. Correct output should be next:

"buckets": [
        {
          "key": "baby tv",
          "doc_count": 4582
        }
        {
          "key": "channel 24",
          "doc_count": 1547
        },..

Why that's happening? How can I see the correct output?

Answer 1

I've found the solution. I just added .keyword after field name:

GET _search
{
"size": 0,
"aggs" : {
    "channels" : {
        "terms" : { "field" : "channelName.keyword" ,
        "size": 1000
        }
    }
}}