* Added an extra `field` parameter to the `percolator` query to indicate what percolator field should be used. This must be an existing field in the mapping of type `percolator`.
* The `.percolator` type is now forbidden. (just like any type that starts with a `.`)
This only applies for new indices created on 5.0 and later. Indices created on previous versions the .percolator type is still allowed to exist.
The new `percolator` field type isn't active in such indices and the `PercolatorQueryCache` knows how to load queries from these legacy indices.
The `PercolatorQueryBuilder` will not enforce that the `field` parameter is of type `percolator`.
Also replaced the PercolatorQueryRegistry with the new PercolatorQueryCache.
The PercolatorFieldMapper stores the rewritten form of each percolator query's xcontext
in a binary doc values field. This make sure that the query rewrite happens only during
indexing (some queries for example fetch shapes, terms in remote indices) and
the speed up the loading of the queries in the percolator query cache.
Because the percolator now works inside the search infrastructure a number of features
(sorting fields, pagination, fetch features) are available out of the box.
The following feature requests are automatically implemented via this refactoring:
Closes#10741Closes#7297Closes#13176Closes#13978Closes#11264Closes#10741Closes#4317
Martijn van Groningen
Clinton Gormley