The count API allows to easily execute a query and get the number of matches for that query. It can be executed across one or more indices. The query can either be provided using a simple query string as a parameter, or using the Query DSL defined within the request body. Here is an example:
PUT /twitter/_doc/1?refresh { "user": "kimchy" } GET /twitter/_count?q=user:kimchy GET /twitter/_count { "query" : { "term" : { "user" : "kimchy" } } }
The query being sent in the body must be nested in a query
key, same as
the search api works
Both examples above do the same thing, which is count the number of
tweets from the twitter
index for a certain user. The result is:
{ "count" : 1, "_shards" : { "total" : 1, "successful" : 1, "skipped" : 0, "failed" : 0 } }
The query is optional, and when not provided, it will use match_all
to
count all the docs.
The count API can be applied to multiple indices.
When executing count using the query parameter q
, the query passed is
a query string using Lucene query parser. There are additional
parameters that can be passed:
Name | Description |
---|---|
| The default field to use when no field prefix is defined within the query. |
| The analyzer name to be used when analyzing the query string. |
| The default operator to be used, can be |
| If set to true will cause format based failures (like providing text to a numeric field) to be ignored. Defaults to false. |
| Should wildcard and prefix queries be analyzed or
not. Defaults to |
| The maximum count for each shard, upon
reaching which the query execution will terminate early.
If set, the response will have a boolean field |
The count can use the Query DSL within
its body in order to express the query that should be executed. The body
content can also be passed as a REST parameter named source
.
Both HTTP GET and HTTP POST can be used to execute count with body. Since not all clients support GET with body, POST is allowed as well.
The count operation is broadcast across all shards. For each shard id group, a replica is chosen and executed against it. This means that replicas increase the scalability of count.
The routing value (a comma separated list of the routing values) can be specified to control which shards the count request will be executed on.