How to query all content from a field in Elasticssearch - elasticsearch

Question

I'm queriying data from Elasticsearch with python. I can query a certain value in a field like this:
GET index/_search
{
"query": {
"match" : {
"somefieldname": "somevalue"
}
}
}
But how can I query all values inside the field somefieldname?
UPDATE:
Here's an example index:
"_index" : „indexname
"_type" : "_doc",
"_id" : "lJlcO3wBhlKWxmXE9jrd",
"_score" : 0,
"_source": {
„field1“: „abc“,
„field2“: „123",
„field3": „def“,
},
"_index" : „indexname
"_type" : "_doc",
"_id" : "lJlcO3wBhlKWxmXE9jrd",
"_score" : 0,
"_source": {
„field1“: „fgh“,
„field2“: „654",
„field3": „kui“,
},
"_index" : „indexname
"_type" : "_doc",
"_id" : "lJlcO3wBhlKWxmXE9jrd",
"_score" : 00,
"_source": {
„field1“: „567“,
„field2“: „gfr",
„field3": „234“,
},
Now I want to query all content from field2 from all docs. So that my output is [„123", „654", „gfr"]
UPDATE:
Index mapping for the field:
{
"myindex" : {
"mappings" : {
"field2" : {
"full_name" : "field2",
"mapping" : {
"field2" : {
"type" : "keyword"
}
}
}
}
}
}

Answer 1

You can use terms aggregation, to get unique values from field2
{
"size": 0,
"aggs": {
"field2values": {
"terms": {
"field": "field2"
}
}
}
}
Search Result would be
"aggregations": {
"field2values": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "123",
"doc_count": 1
},
{
"key": "654",
"doc_count": 1
},
{
"key": "gfr",
"doc_count": 1
}
]
}
}