# Continuous transform missing some documents, but they show in /\_preview

**URL:** https://discuss.elastic.co/t/continuous-transform-missing-some-documents-but-they-show-in-preview/237614
**Category:** Kibana
**Created:** [June 18, 2020, 10:18am UTC](https://discuss.elastic.co/t/continuous-transform-missing-some-documents-but-they-show-in-preview/237614 "2020-06-18T10:18:07Z")
**Posts on this page:** 1
**Showing post:** 6

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### Author: ![Hendrik\_Muhs](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/hendrik_muhs/32/25802_2.png) [@Hendrik\_Muhs](https://discuss.elastic.co/u/Hendrik_Muhs)
#### Post date: [June 24, 2020, 1:03pm UTC](https://discuss.elastic.co/t/continuous-transform-missing-some-documents-but-they-show-in-preview/237614/6 "2020-06-24T13:03:15Z")

</div>

Using the `_update` API is not supported for continuous transforms, it may or may not work. In a nutshell a continuous transform works in 2 steps:

1. find the changes
2. recalculate the changed buckets

If you use `_update` its not visible for step 1. However if you change the bucket by another non `_update` change almost at the same time, you are lucky.

For seeing what transform does behind the scenes, you can use:

```auto
PUT /_cluster/settings
{
   "transient": {
      "logger.org.elasticsearch.xpack.transform.transforms": "trace"
   }
}

```

to see the queries it runs.

Sporadic messages shouldn't be a problem, however logstash has a batch [delay](https://www.elastic.co/guide/en/logstash/current/logstash-settings-file.html). I still think the docs are missed due to ingest delays.

Again, moving the [timestamp to ingest](https://discuss.elastic.co/t/dec-12th-2018-en-elasticsearch-automatically-adding-a-timestamp-to-documents/159314) could help to get it closer to indexing. If you want to keep the logstash one, you can use another timestamp field (might also be helpful for debugging, e.g. by aggregating the difference between the two).

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_[View the full topic](https://discuss.elastic.co/t/continuous-transform-missing-some-documents-but-they-show-in-preview/237614)._