---
navigation_title: "Time series"
mapped_pages:
  - https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-time-series-aggregation.html
---

# Time series aggregation [search-aggregations-bucket-time-series-aggregation]


::::{warning}
This functionality is in technical preview and may be changed or removed in a future release. Elastic will work to fix any issues, but features in technical preview are not subject to the support SLA of official GA features.
::::


The time series aggregation queries data created using a [Time series data stream (TSDS)](docs-content://manage-data/data-store/data-streams/time-series-data-stream-tsds.md). This is typically data such as metrics or other data streams with a time component, and requires creating an index using the time series mode.

::::{note}
Refer to the [TSDS documentation](docs-content://manage-data/data-store/data-streams/time-series-data-stream-tsds.md#differences-from-regular-data-stream) to learn more about the key differences from regular data streams.

::::


Data can be added to the time series index like other indices:

```js
PUT /my-time-series-index-0/_bulk
{ "index": {} }
{ "key": "a", "val": 1, "@timestamp": "2022-01-01T00:00:10Z" }
{ "index": {}}
{ "key": "a", "val": 2, "@timestamp": "2022-01-02T00:00:00Z" }
{ "index": {} }
{ "key": "b", "val": 2, "@timestamp": "2022-01-01T00:00:10Z" }
{ "index": {}}
{ "key": "b", "val": 3, "@timestamp": "2022-01-02T00:00:00Z" }
```

To perform a time series aggregation, specify "time_series" as the aggregation type. When the boolean "keyed" is true, each bucket is given a unique key.

$$$time-series-aggregation-example$$$

```js
GET /_search
{
  "aggs": {
    "ts": {
      "time_series": { "keyed": false }
    }
  }
}
```

This will return all results in the time series, however a more typical query will use sub aggregations to reduce the date returned to something more relevant.

## Size [search-aggregations-bucket-time-series-aggregation-size]

By default, `time series` aggregations return 10000 results. The "size" parameter can be used to limit the results further. Alternatively, using sub aggregations can limit the amount of values returned as a time series aggregation.


## Keyed [search-aggregations-bucket-time-series-aggregation-keyed]

The `keyed` parameter determines if buckets are returned as a map with unique keys per bucket. By default with `keyed` set to false, buckets are returned as an array.


## Limitations [times-series-aggregations-limitations]

The `time_series` aggregation has many limitations. Many aggregation performance optimizations are disabled when using the `time_series` aggregation. For example the filter by filter optimization or collect mode breath first (`terms` and `multi_terms` aggregation forcefully use the depth first collect mode).

The following aggregations also fail to work if used in combination with the `time_series` aggregation: `auto_date_histogram`, `variable_width_histogram`, `rare_terms`, `global`, `composite`, `sampler`, `random_sampler` and `diversified_sampler`.