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95f46f1212
We now have a very useful annotation to mark features or parameters as experimental. Let's use it! This commit replaces some custom text warnings with this annotation and adds this annotation to some existing features/parameters: - inner_hits (unreleased yet) - terminate_after (released in 1.4) - per-bucket doc count errors in the terms agg (released in 1.4) I also tagged with this annotation settings which should either be not needed (like the ability to evict entries from the filter cache based on time) or that are too deep into the way that Elasticsearch works like the Directory implementation or merge settings. Close #9563
96 lines
3.0 KiB
Plaintext
96 lines
3.0 KiB
Plaintext
[[search-count]]
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== Count API
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The count API allows to easily execute a query and get the number of
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matches for that 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/_count?q=user:kimchy'
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$ curl -XGET 'http://localhost:9200/twitter/tweet/_count' -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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the <<search-search,search api>> works
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Both examples above do the same thing, which is count the number of
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tweets from the twitter index for a certain user. The result is:
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[source,js]
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--------------------------------------------------
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{
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"count" : 1,
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"_shards" : {
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"total" : 5,
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"successful" : 5,
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"failed" : 0
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}
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}
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--------------------------------------------------
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The query is optional, and when not provided, it will use `match_all` to
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count all the docs.
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[float]
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=== Multi index, Multi type
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The count 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 count 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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|terminate_after |experimental[] The maximum count for each shard, upon
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reaching which the query execution will terminate early.
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If set, the response will have a boolean field `terminated_early` to
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indicate whether the query execution has actually terminated_early.
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Defaults to no terminate_after.
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|=======================================================================
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[float]
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=== Request Body
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The count 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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Both HTTP GET and HTTP POST can be used to execute count 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 count 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 count.
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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 count request will be executed on.
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