95 lines
3.1 KiB
Plaintext
95 lines
3.1 KiB
Plaintext
[[search-exists]]
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== Search Exists API
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The exists API allows to easily determine if any
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matching documents exist for a provided query. It can be executed across one or more indices
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and across one or more types. The query can either be provided using a
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simple query string as a parameter, or using the
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<<query-dsl,Query DSL>> defined within the request
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body. Here is an example:
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[source,js]
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--------------------------------------------------
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$ curl -XGET 'http://localhost:9200/twitter/tweet/_search/exists?q=user:kimchy'
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$ curl -XGET 'http://localhost:9200/twitter/tweet/_search/exists' -d '
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{
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"query" : {
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"term" : { "user" : "kimchy" }
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}
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}'
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--------------------------------------------------
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NOTE: The query being sent in the body must be nested in a `query` key, same as
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how the <<search-search,search api>> works.
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Both the examples above do the same thing, which is determine the existence of
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tweets from the twitter index for a certain user. The response body will be of
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the following format:
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[source,js]
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--------------------------------------------------
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{
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"exists" : true
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}
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--------------------------------------------------
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[float]
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=== Multi index, Multi type
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The exists API can be applied to <<search-multi-index-type,multiple types in multiple indices>>.
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[float]
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=== Request Parameters
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When executing exists using the query parameter `q`, the query passed is
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a query string using Lucene query parser. There are additional
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parameters that can be passed:
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[cols="<,<",options="header",]
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|=======================================================================
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|Name |Description
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|`df` |The default field to use when no field prefix is defined within the
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query.
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|`analyzer` |The analyzer name to be used when analyzing the query string.
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|`default_operator` |The default operator to be used, can be `AND` or
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`OR`. Defaults to `OR`.
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|`lenient` |If set to true will cause format based failures (like
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providing text to a numeric field) to be ignored. Defaults to false.
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|`lowercase_expanded_terms` |Should terms be automatically lowercased or
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not. Defaults to `true`.
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|`analyze_wildcard` |Should wildcard and prefix queries be analyzed or
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not. Defaults to `false`.
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|=======================================================================
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[float]
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=== Request Body
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The exists API can use the <<query-dsl,Query DSL>> within
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its body in order to express the query that should be executed. The body
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content can also be passed as a REST parameter named `source`.
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HTTP GET and HTTP POST can be used to execute exists with body.
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Since not all clients support GET with body, POST is allowed as well.
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[float]
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=== Distributed
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The exists operation is broadcast across all shards. For each shard id
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group, a replica is chosen and executed against it. This means that
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replicas increase the scalability of exists. The exists operation also
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early terminates shard requests once the first shard reports matched
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document existence.
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[float]
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=== Routing
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The routing value (a comma separated list of the routing values) can be
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specified to control which shards the exists request will be executed on.
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