本地英文版地址: ../en/mapping-index-field.html
_index fieldedit
When performing queries across multiple indexes, it is sometimes desirable to
add query clauses that are associated with documents of only certain indexes.
The _index field allows matching on the index a document was indexed into.
Its value is accessible in certain queries and aggregations, and when sorting
or scripting:
PUT index_1/_doc/1
{
"text": "Document in index 1"
}
PUT index_2/_doc/2?refresh=true
{
"text": "Document in index 2"
}
GET index_1,index_2/_search
{
"query": {
"terms": {
"_index": ["index_1", "index_2"]
}
},
"aggs": {
"indices": {
"terms": {
"field": "_index",
"size": 10
}
}
},
"sort": [
{
"_index": {
"order": "asc"
}
}
],
"script_fields": {
"index_name": {
"script": {
"lang": "painless",
"source": "doc['_index']"
}
}
}
}
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Querying on the |
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Aggregating on the |
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Sorting on the |
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Accessing the |
The _index field is exposed virtually — it is not added to the Lucene index
as a real field. This means that you can use the _index field in a term or
terms query (or any query that is rewritten to a term query, such as the
match, query_string or simple_query_string query), as well as prefix
and wildcard queries. However, it does not support regexp and fuzzy
queries.
Queries on the _index field accept index aliases in addition to concrete
index names.
When specifying a remote index name such as cluster_1:index_3, the
query must contain the separator character :. For example, a wildcard query
on cluster_*:index_3 would match documents from the remote index. However, a
query on cluster*index_1 is only matched against local indices, since no
separator is present. This behavior aligns with the usual resolution rules for
remote index names.