76 lines
2.9 KiB
Plaintext
76 lines
2.9 KiB
Plaintext
[[query-dsl]]
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= Query DSL
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[partintro]
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--
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Elasticsearch provides a full Query DSL (Domain Specific Language) based on JSON to define queries.
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Think of the Query DSL as an AST (Abstract Syntax Tree) of queries, consisting of two types of
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clauses:
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Leaf query clauses::
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Leaf query clauses look for a particular value in a particular field, such as the
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<<query-dsl-match-query,`match`>>, <<query-dsl-term-query,`term`>> or
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<<query-dsl-range-query,`range`>> queries. These queries can be used
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by themselves.
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Compound query clauses::
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Compound query clauses wrap other leaf *or* compound queries and are used to combine
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multiple queries in a logical fashion (such as the
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<<query-dsl-bool-query,`bool`>> or <<query-dsl-dis-max-query,`dis_max`>> query),
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or to alter their behaviour (such as the
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<<query-dsl-constant-score-query,`constant_score`>> query).
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Query clauses behave differently depending on whether they are used in
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<<query-filter-context,query context or filter context>>.
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[[query-dsl-allow-expensive-queries]]
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Allow expensive queries::
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Certain types of queries will generally execute slowly due to the way they are implemented, which can affect
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the stability of the cluster. Those queries can be categorised as follows:
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* Queries that need to do linear scans to identify matches:
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** <<query-dsl-script-query, `script queries`>>
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* Queries that have a high up-front cost :
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** <<query-dsl-fuzzy-query,`fuzzy queries`>> (except on <<wildcard, `wildcard`>> fields)
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** <<query-dsl-regexp-query,`regexp queries`>> (except on <<wildcard, `wildcard`>> fields)
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** <<query-dsl-prefix-query,`prefix queries`>> (except on <<wildcard, `wildcard`>> fields or those without <<index-prefixes, `index_prefixes`>>)
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** <<query-dsl-wildcard-query, `wildcard queries`>> (except on <<wildcard, `wildcard`>> fields)
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** <<query-dsl-range-query, `range queries>> on <<text, `text`>> and <<keyword, `keyword`>> fields
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* <<joining-queries, `Joining queries`>>
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* Queries on <<prefix-trees, deprecated geo shapes>>
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* Queries that may have a high per-document cost:
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** <<query-dsl-script-score-query, `script score queries`>>
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** <<query-dsl-percolate-query, `percolate queries`>>
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The execution of such queries can be prevented by setting the value of the `search.allow_expensive_queries`
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setting to `false` (defaults to `true`).
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--
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include::query-dsl/query_filter_context.asciidoc[]
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include::query-dsl/compound-queries.asciidoc[]
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include::query-dsl/full-text-queries.asciidoc[]
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include::query-dsl/geo-queries.asciidoc[]
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include::query-dsl/shape-queries.asciidoc[]
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include::query-dsl/joining-queries.asciidoc[]
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include::query-dsl/match-all-query.asciidoc[]
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include::query-dsl/span-queries.asciidoc[]
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include::query-dsl/special-queries.asciidoc[]
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include::query-dsl/term-level-queries.asciidoc[]
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include::query-dsl/minimum-should-match.asciidoc[]
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include::query-dsl/multi-term-rewrite.asciidoc[]
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include::query-dsl/regexp-syntax.asciidoc[]
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