OpenSearch/docs/reference/mapping/fields/index-field.asciidoc
Ryan Ernst a03b6c2fa5 Scripting: Change keys for inline/stored scripts to source/id (#25127)
This commit adds back "id" as the key within a script to specify a
stored script (which with file scripts now gone is no longer ambiguous).
It also adds "source" as a replacement for "code". This is in an attempt
to normalize how scripts are specified across both put stored scripts and script usages, including search template requests. This also deprecates the old inline/stored keys.
2017-06-09 08:29:25 -07:00

67 lines
1.6 KiB
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[[mapping-index-field]]
=== `_index` field
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 `term`, or `terms` queries, aggregations,
scripts, and when sorting:
NOTE: The `_index` is exposed as a virtual field -- 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),
but it does not support `prefix`, `wildcard`, `regexp`, or `fuzzy` queries.
[source,js]
--------------------------
# Example documents
PUT index_1/my_type/1
{
"text": "Document in index 1"
}
PUT index_2/my_type/2?refresh=true
{
"text": "Document in index 2"
}
GET index_1,index_2/_search
{
"query": {
"terms": {
"_index": ["index_1", "index_2"] <1>
}
},
"aggs": {
"indices": {
"terms": {
"field": "_index", <2>
"size": 10
}
}
},
"sort": [
{
"_index": { <3>
"order": "asc"
}
}
],
"script_fields": {
"index_name": {
"script": {
"lang": "painless",
"source": "doc['_index']" <4>
}
}
}
}
--------------------------
// CONSOLE
<1> Querying on the `_index` field
<2> Aggregating on the `_index` field
<3> Sorting on the `_index` field
<4> Accessing the `_index` field in scripts