elasticsearch/docs/reference/mapping/fields/ignored-field.asciidoc
Christoph Büscher f522de6b56
[Docs] Clarify ignore_above behaviour (#79705)
Clarify that `keyword` fields that exceed the optional `ignore_above` setting
are inlcuded in the `_ignored` fields since 7.14.

Closes #79605
2021-10-25 20:27:02 +02:00

42 lines
1.2 KiB
Text

[[mapping-ignored-field]]
=== `_ignored` field
The `_ignored` field indexes and stores the names of every field in a document
that has been ignored when the document was indexed. This can, for example,
be the case when the field was malformed and <<ignore-malformed,`ignore_malformed`>>
was turned on, or when a `keyword` fields value exceeds its optional
<<ignore-above,`ignore_above`>> setting.
This field is searchable with <<query-dsl-term-query,`term`>>,
<<query-dsl-terms-query,`terms`>> and <<query-dsl-exists-query,`exists`>>
queries, and is returned as part of the search hits.
For instance the below query matches all documents that have one or more fields
that got ignored:
[source,console]
--------------------------------------------------
GET _search
{
"query": {
"exists": {
"field": "_ignored"
}
}
}
--------------------------------------------------
Similarly, the below query finds all documents whose `@timestamp` field was
ignored at index time:
[source,console]
--------------------------------------------------
GET _search
{
"query": {
"term": {
"_ignored": "@timestamp"
}
}
}
--------------------------------------------------