looking into TERMS aggs vs index false

looking into TERMS aggs vs index false

# looking into TERMS aggs vs index false 
# start clean
DELETE test

# define an index with two fields, with index
# set to true & false
PUT test
{
  "mappings": {
    "_doc": {
      "properties": {
        "index_true": {
          "type": "keyword",
          "index": "true"
        },
        "index_false": {
          "type": "keyword",
          "index": "false"
        }
      }
    }
  }
}

# index example documents
PUT test/_doc/1
{
  "index_true": "indexed1",
  "index_false": "ignored1"
}

PUT test/_doc/2
{
  "index_true": "indexed2",
  "index_false": "ignored2"
}

# search for indexed content, this works
GET test/_search
{
  "query": {
    "regexp": {
      "index_true": "index.*"
    }
  }
}

# search for indexed content, this fails with
# HTTP/1.1 400 Bad Request
GET test/_search
{
  "query": {
    "regexp": {
      "index_false": "ignore.*"
    }
  }
}

# aggs vs indexed keyword field, expected result:
# "my_indexed_field_terms":{
#   "doc_count_error_upper_bound":0,
#   "sum_other_doc_count":0,
#   "buckets":[
#     {"key":"indexed1","doc_count":1},
#     {"key":"indexed2","doc_count":1}
#   ]
# }
GET test/_search
{
  "size": 0,
  "aggs": {
    "my_indexed_field_terms": {
      "terms": {
        "field": "index_true",
        "size": 10
      }
    }
  }
}

# aggs vs indexed keyword field, expected result:
# "my_indexed_field_terms":{
#   "doc_count_error_upper_bound":0,
#   "sum_other_doc_count":0,
#   "buckets":[
#     {"key":"ignored1","doc_count":1},
#     {"key":"ignored2","doc_count":1}
#   ]
# }
GET test/_search
{
  "size": 0,
  "aggs": {
    "my_NOT_indexed_field_terms": {
      "terms": {
        "field": "index_false",
        "size": 10
      }
    }
  }
}