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Diffstat (limited to 'docs/reference/query-dsl/queries/multi-term-rewrite.asciidoc')
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diff --git a/docs/reference/query-dsl/queries/multi-term-rewrite.asciidoc b/docs/reference/query-dsl/queries/multi-term-rewrite.asciidoc new file mode 100644 index 0000000..135be67 --- /dev/null +++ b/docs/reference/query-dsl/queries/multi-term-rewrite.asciidoc @@ -0,0 +1,42 @@ +[[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: + +* When not set, or set to `constant_score_auto`, defaults to +automatically choosing either `constant_score_boolean` or +`constant_score_filter` based on query characteristics. +* `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`). +* `constant_score_filter`: A rewrite method that first creates a private +Filter by visiting each term in sequence and marking all docs for that +term. Matching documents are assigned a constant score equal to the +query's boost. +* `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. + |