# Retrieve geolocation sampled data **URL:** \ **Category:** Elasticsearch\ **Created:** [July 19, 2019, 5:15pm UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432 "2019-07-19T17:15:12Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![MarcoAbi](https://avatars.discourse-cdn.com/v4/letter/m/dfb087/32.png) [@MarcoAbi](https://discuss.elastic.co/u/MarcoAbi)\ **Post date:** [July 19, 2019, 5:15pm UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/1 "2019-07-19T17:15:12Z")
Hello, I have an index that collects 1 geospatial point data every second per each device (eg, a moving car). Now, I need to collect the geopoint in order to plot the path that the given vehicle has made. However, plotting a path of 2 hours long with a such frequency ends up with 3600\*2 datapoints, that is definitely too much for this use case (however, I do need such resolution for other use cases). Is there a way to query the index and retrieve only a sample of those 7200 points? Thanks a lot! Marco ---
**Author:** ![Mark\_Harwood](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mark_harwood/32/10538_2.png) [@Mark\_Harwood](https://discuss.elastic.co/u/Mark_Harwood)\ **Post date:** [July 19, 2019, 5:37pm UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/2 "2019-07-19T17:37:03Z")
> [@MarcoAbi](#): > > Is there a way to query the index and retrieve only a sample of those 7200 points? We have a `sampler` aggregation which can take the top N hits and feed them to a contained child aggregation. Additionally there's a [diversified\_sampler](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-diversified-sampler-aggregation.html) which may be useful to ensure the selection of docs is not focused in any one particular time range or location. ---
**Author:** ![MarcoAbi](https://avatars.discourse-cdn.com/v4/letter/m/dfb087/32.png) [@MarcoAbi](https://discuss.elastic.co/u/MarcoAbi)\ **Post date:** [July 19, 2019, 9:02pm UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/3 "2019-07-19T21:02:25Z")
Wonderful! Thanks a lot Mark. Elastic is a masterpiece! ---
**Author:** ![MarcoAbi](https://avatars.discourse-cdn.com/v4/letter/m/dfb087/32.png) [@MarcoAbi](https://discuss.elastic.co/u/MarcoAbi)\ **Post date:** [July 22, 2019, 2:23pm UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/4 "2019-07-22T14:23:07Z")
Hello Mark, I'm experiencing problems with the diversified\_sampler query. This is the query I'm setting up: ``` GET gps_data/_search { "query": { "bool": { "must": [ { "term" : { "deviceId": 123 } }, { "range": { "start": { "gte": 1562047171000, "lte": 1562047514000, "format": "epoch_millis" } } } ], "filter": [], "should": [], "must_not": [] } }, "aggs": { "my_unbiased_sample": { "diversified_sampler": { "shard_size": 200, "field" : "eventTime" }, "aggs": { "keywords": { "significant_terms": { "field": "location" } } } } } } ``` Elastic replies back that "significant\_terms aggregation cannot be applied to field [location]. It can only be applied to numeric or string fields." I'm wondering if I'm setting up the query correctly or actually there is this limitation in the query. Thanks! Marco ---
**Author:** ![Mark\_Harwood](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mark_harwood/32/10538_2.png) [@Mark\_Harwood](https://discuss.elastic.co/u/Mark_Harwood)\ **Post date:** [July 22, 2019, 3:12pm UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/5 "2019-07-22T15:12:36Z")
> [@MarcoAbi](#): > > Elastic replies back that "significant\_terms aggregation cannot be applied to field [location]. Wasn't the goal to put your geo aggregation under the sampler? You may need to have a higher-granularity field for diversification too - if the accuracy is millisecond level you'll only be limiting the number of docs considered per millisecond. You might need to use a [script](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-diversified-sampler-aggregation.html#_scripted_example) to "round up" the times to hours or minutes or whatever suits as your unit for de-duplicating ---
**Author:** ![MarcoAbi](https://avatars.discourse-cdn.com/v4/letter/m/dfb087/32.png) [@MarcoAbi](https://discuss.elastic.co/u/MarcoAbi)\ **Post date:** [July 23, 2019, 6:48am UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/6 "2019-07-23T06:48:48Z")
Ok, got your point. I have to refactor the index a bit than, I want to avoid scripted fields to maintain performances high enough. Meanwhile I’m using the functional query with a random function. This is creating the uniform scoring that allows me to drop out enough data and have a rough good quality samples. Thanks again for your support. ---
**Author:** ![Mark\_Harwood](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/mark_harwood/32/10538_2.png) [@Mark\_Harwood](https://discuss.elastic.co/u/Mark_Harwood)\ **Post date:** [July 23, 2019, 11:20am UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/7 "2019-07-23T11:20:27Z")
> [@MarcoAbi](#): > > I’m using the functional query with a random function. Sounds like a good approach. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [August 20, 2019, 11:20am UTC](https://discuss.elastic.co/t/retrieve-geolocation-sampled-data/191432/8 "2019-08-20T11:20:30Z")
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