OpenSearch/docs/reference/query-dsl/indices-query.asciidoc

[[query-dsl-indices-query]]
=== Indices Query

The `indices` query is useful in cases where a search is executed across
multiple indices. It allows to specify a list of index names and an inner
query that is only executed for indices matching names on that list.
For other indices that are searched, but that don't match entries
on the list, the alternative `no_match_query` is executed.

[source,js]
--------------------------------------------------
GET /_search
{
    "query": {
        "indices" : {
            "indices" : ["index1", "index2"],
            "query" : { "term" : { "tag" : "wow" } },
            "no_match_query" : { "term" : { "tag" : "kow" } }
        }
    }
}
--------------------------------------------------
// CONSOLE 

You can use the `index` field to provide a single index.

`no_match_query` can also have "string" value of `none` (to match no
documents), and `all` (to match all). Defaults to `all`.

`query` is mandatory, as well as `indices` (or `index`).