Terms Query
editTerms Query
editFilters documents that have fields that match any of the provided terms (not analyzed). For example:
GET /_search
{
"query": {
"constant_score" : {
"filter" : {
"terms" : { "user" : ["kimchy", "elasticsearch"]}
}
}
}
}
The terms query is also aliased with in as the filter name for
simpler usage
[5.0.0]
Deprecated in 5.0.0. use terms instead
.
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
editAt first we index the information for user with id 2, specifically, its followers, then index a tweet from user with id 1. Finally we search on all the tweets that match the followers of user 2.
PUT /users/user/2
{
"followers" : ["1", "3"]
}
PUT /tweets/tweet/1
{
"user" : "1"
}
GET /tweets/_search
{
"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:
PUT /users/user/2
{
"followers" : [
{
"id" : "1"
},
{
"id" : "2"
}
]
}
In which case, the lookup path will be followers.id.