elasticsearch/docs/reference/mapping/fields/index-field.asciidoc

[[mapping-index-field]]
=== `_index`

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.
Migrated documentation into the main repo 2013-08-29 07:24:34 +08:00			`[[mapping-index-field]]`
			=== `_index`

Mappings: Remove ability to configure _index The `_index` field is now a completely virtual field thanks to #12027. It is no longer necessary to index the actual value of the index name. closes #12329 2015-07-21 14:54:35 +08:00			`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.`