WARNING: Version 2.2 of Elasticsearch has passed its EOL date.
This documentation is no longer being maintained and may be removed. If you are running this version, we strongly advise you to upgrade. For the latest information, see the current release documentation.
Terms Query
editTerms Query
editFilters documents that have fields that match any of the provided terms (not analyzed). For example:
{ "constant_score" : { "filter" : { "terms" : { "user" : ["kimchy", "elasticsearch"]} } } }
The terms
query is also aliased with in
as the filter name for
simpler usage.
Terms lookup mechanism
editWhen it’s needed to specify a terms
filter with a lot of terms it can
be beneficial to fetch those term values from a document in an index. A
concrete example would be to filter tweets tweeted by your followers.
Potentially the amount of user ids specified in the terms filter can be
a lot. In this scenario it makes sense to use the terms filter’s terms
lookup mechanism.
The terms lookup mechanism supports the following options:
|
The index to fetch the term values from. Defaults to the current index. |
|
The type to fetch the term values from. |
|
The id of the document to fetch the term values from. |
|
The field specified as path to fetch the actual values for the
|
|
A custom routing value to be used when retrieving the external terms doc. |
The values for the terms
filter will be fetched from a field in a
document with the specified id in the specified type and index.
Internally a get request is executed to fetch the values from the
specified path. At the moment for this feature to work the _source
needs to be stored.
Also, consider using an index with a single shard and fully replicated across all nodes if the "reference" terms data is not large. The lookup terms filter will prefer to execute the get request on a local node if possible, reducing the need for networking.
Terms lookup twitter example
edit# index the information for user with id 2, specifically, its followers curl -XPUT localhost:9200/users/user/2 -d '{ "followers" : ["1", "3"] }' # index a tweet, from user with id 2 curl -XPUT localhost:9200/tweets/tweet/1 -d '{ "user" : "2" }' # search on all the tweets that match the followers of user 2 curl -XGET localhost:9200/tweets/_search -d '{ "query" : { "terms" : { "user" : { "index" : "users", "type" : "user", "id" : "2", "path" : "followers" } } } }'
The structure of the external terms document can also include array of inner objects, for example:
curl -XPUT localhost:9200/users/user/2 -d '{ "followers" : [ { "id" : "1" }, { "id" : "2" } ] }'
In which case, the lookup path will be followers.id
.