OpenSearch/docs/reference/query-dsl/multi-term-rewrite.asciidoc

[[query-dsl-multi-term-rewrite]]
== Multi Term Query Rewrite

Multi term queries, like
<<query-dsl-wildcard-query,wildcard>> and
<<query-dsl-prefix-query,prefix>> are called
multi term queries and end up going through a process of rewrite. This
also happens on the
<<query-dsl-query-string-query,query_string>>.
All of those queries allow to control how they will get rewritten using
the `rewrite` parameter:

* `constant_score` (default): A rewrite method that performs like
`constant_score_boolean` when there are few matching terms and otherwise
visits all matching terms in sequence and marks documents for that term.
Matching documents are assigned a constant score equal to the query's
boost.
* `scoring_boolean`: A rewrite method that first translates each term
into a should clause in a boolean query, and keeps the scores as
computed by the query. Note that typically such scores are meaningless
to the user, and require non-trivial CPU to compute, so it's almost
always better to use `constant_score_auto`. This rewrite method will hit
too many clauses failure if it exceeds the boolean query limit (defaults
to `1024`).
* `constant_score_boolean`: Similar to `scoring_boolean` except scores
are not computed. Instead, each matching document receives a constant
score equal to the query's boost. This rewrite method will hit too many
clauses failure if it exceeds the boolean query limit (defaults to
`1024`).
* `top_terms_N`: A rewrite method that first translates each term into
should clause in boolean query, and keeps the scores as computed by the
query. This rewrite method only uses the top scoring terms so it will
not overflow boolean max clause count. The `N` controls the size of the
top scoring terms to use.
* `top_terms_boost_N`: A rewrite method that first translates each term
into should clause in boolean query, but the scores are only computed as
the boost. This rewrite method only uses the top scoring terms so it
will not overflow the boolean max clause count. The `N` controls the
size of the top scoring terms to use.
* `top_terms_blended_freqs_N`: A rewrite method that first translates each
term into should clause in boolean query, but all term queries compute scores
as if they had the same frequency. In practice the frequency which is used
is the maximum frequency of all matching terms. This rewrite method only uses
the top scoring terms so it will not overflow boolean max clause count. The
`N` controls the size of the top scoring terms to use.