NOTE: You are looking at documentation for an older release. For the latest information, see the current release documentation.
normalizer
editnormalizer
editThe normalizer property of keyword fields is similar to
analyzer except that it guarantees that the analysis chain
produces a single token.
The normalizer is applied prior to indexing the keyword, as well as at
search-time when the keyword field is searched via a query parser such as
the match query or via a term-level query
such as the term query.
PUT index
{
"settings": {
"analysis": {
"normalizer": {
"my_normalizer": {
"type": "custom",
"char_filter": [],
"filter": ["lowercase", "asciifolding"]
}
}
}
},
"mappings": {
"_doc": {
"properties": {
"foo": {
"type": "keyword",
"normalizer": "my_normalizer"
}
}
}
}
}
PUT index/_doc/1
{
"foo": "BÀR"
}
PUT index/_doc/2
{
"foo": "bar"
}
PUT index/_doc/3
{
"foo": "baz"
}
POST index/_refresh
GET index/_search
{
"query": {
"term": {
"foo": "BAR"
}
}
}
GET index/_search
{
"query": {
"match": {
"foo": "BAR"
}
}
}
The above queries match documents 1 and 2 since BÀR is converted to bar at
both index and query time.
{
"took": $body.took,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped" : 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 0.2876821,
"hits": [
{
"_index": "index",
"_type": "_doc",
"_id": "2",
"_score": 0.2876821,
"_source": {
"foo": "bar"
}
},
{
"_index": "index",
"_type": "_doc",
"_id": "1",
"_score": 0.2876821,
"_source": {
"foo": "BÀR"
}
}
]
}
}
Also, the fact that keywords are converted prior to indexing also means that aggregations return normalized values:
GET index/_search
{
"size": 0,
"aggs": {
"foo_terms": {
"terms": {
"field": "foo"
}
}
}
}
returns
{
"took": 43,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped" : 0,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 0.0,
"hits": []
},
"aggregations": {
"foo_terms": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "bar",
"doc_count": 2
},
{
"key": "baz",
"doc_count": 1
}
]
}
}
}