OpenSearch/docs/reference/query-dsl/terms-set-query.asciidoc
Jason Tedor 4a4e3d70d5
Default to one shard (#30539)
This commit changes the default out-of-the-box configuration for the
number of shards from five to one. We think this will help address a
common problem of oversharding. For users with time-based indices that
need a different default, this can be managed with index templates. For
users with non-time-based indices that find they need to re-shard with
the split API in place they no longer need to resort only to
reindexing.

Since this has the impact of changing the default number of shards used
in REST tests, we want to ensure that we still have coverage for issues
that could arise from multiple shards. As such, we randomize (rarely)
the default number of shards in REST tests to two. This is managed via a
global index template. However, some tests check the templates that are
in the cluster state during the test. Since this template is randomly
there, we need a way for tests to skip adding the template used to set
the number of shards to two. For this we add the default_shards feature
skip. To avoid having to write our docs in a complicated way because
sometimes they might be behind one shard, and sometimes they might be
behind two shards we apply the default_shards feature skip to all docs
tests. That is, these tests will always run with the default number of
shards (one).
2018-05-14 12:22:35 -04:00

123 lines
2.9 KiB
Plaintext

[[query-dsl-terms-set-query]]
=== Terms Set Query
experimental[The terms_set query is a new query and its syntax may change in the future]
Returns any documents that match with at least one or more of the
provided terms. The terms are not analyzed and thus must match exactly.
The number of terms that must match varies per document and is either
controlled by a minimum should match field or computed per document in
a minimum should match script.
The field that controls the number of required terms that must match must
be a number field:
[source,js]
--------------------------------------------------
PUT /my-index
{
"mappings": {
"_doc": {
"properties": {
"required_matches": {
"type": "long"
}
}
}
}
}
PUT /my-index/_doc/1?refresh
{
"codes": ["ghi", "jkl"],
"required_matches": 2
}
PUT /my-index/_doc/2?refresh
{
"codes": ["def", "ghi"],
"required_matches": 2
}
--------------------------------------------------
// CONSOLE
// TESTSETUP
An example that uses the minimum should match field:
[source,js]
--------------------------------------------------
GET /my-index/_search
{
"query": {
"terms_set": {
"codes" : {
"terms" : ["abc", "def", "ghi"],
"minimum_should_match_field": "required_matches"
}
}
}
}
--------------------------------------------------
// CONSOLE
Response:
[source,js]
--------------------------------------------------
{
"took": 13,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped" : 0,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.87546873,
"hits": [
{
"_index": "my-index",
"_type": "_doc",
"_id": "2",
"_score": 0.87546873,
"_source": {
"codes": ["def", "ghi"],
"required_matches": 2
}
}
]
}
}
--------------------------------------------------
// TESTRESPONSE[s/"took": 13,/"took": "$body.took",/]
Scripts can also be used to control how many terms are required to match
in a more dynamic way. For example a create date or a popularity field
can be used as basis for the number of required terms to match.
Also the `params.num_terms` parameter is available in the script to indicate the
number of terms that have been specified.
An example that always limits the number of required terms to match to never
become larger than the number of terms specified:
[source,js]
--------------------------------------------------
GET /my-index/_search
{
"query": {
"terms_set": {
"codes" : {
"terms" : ["abc", "def", "ghi"],
"minimum_should_match_script": {
"source": "Math.min(params.num_terms, doc['required_matches'].value)"
}
}
}
}
}
--------------------------------------------------
// CONSOLE