# Folder caching/refreshes

**URL:** <https://community.dremio.com/t/folder-caching-refreshes/2377>\
**Category:** Uncategorized\
**Created:** [December 4, 2018, 2:58pm UTC](https://community.dremio.com/t/folder-caching-refreshes/2377 "2018-12-04T14:58:02Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Matt\_Blye](https://avatars.discourse-cdn.com/v4/letter/m/58f4c7/32.png) [@Matt\_Blye](https://community.dremio.com/u/Matt_Blye)\
**Post date:** [December 4, 2018, 2:58pm UTC](https://community.dremio.com/t/folder-caching-refreshes/2377/1 "2018-12-04T14:58:02Z")

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(running version 2.1 at the moment)

I have a folder in a NAS source with multiple tsv files in it. I configured the folder while data was being written into it, and found that the queries only performed on files that were there when the folder was configured. Subsequent runs of simple “select count(\*)” queries did not show increased rows, despite new files being written into the folder.

Am I missing something simple here? Thanks.

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**Author:** ![kelly](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/kelly/32/11_2.png) [@kelly](https://community.dremio.com/u/kelly)\
**Post date:** [December 4, 2018, 4:23pm UTC](https://community.dremio.com/t/folder-caching-refreshes/2377/2 "2018-12-04T16:23:39Z")

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Did you have a look at this page from the docs?

[https://docs.dremio.com/advanced-administration/metadata-caching.html](https://docs.dremio.com/advanced-administration/metadata-caching.html)

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<div class="post-metadata">

**Author:** ![Matt\_Blye](https://avatars.discourse-cdn.com/v4/letter/m/58f4c7/32.png) [@Matt\_Blye](https://community.dremio.com/u/Matt_Blye)\
**Post date:** [December 4, 2018, 5:07pm UTC](https://community.dremio.com/t/folder-caching-refreshes/2377/3 "2018-12-04T17:07:32Z")

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That page specifically says : “Dataset Discovery option is not available for file-system sources such as HDFS, MapR-FS or NAS”. This is a NAS source.

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<div class="post-metadata">

**Author:** ![kelly](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/kelly/32/11_2.png) [@kelly](https://community.dremio.com/u/kelly)\
**Post date:** [December 4, 2018, 6:39pm UTC](https://community.dremio.com/t/folder-caching-refreshes/2377/4 "2018-12-04T18:39:43Z")

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The first setting pertains to discovery of new tables.

The second setting is the one you’re interested in. You essentially have three options:

1. Dremio refreshes its catalog on a schedule you define.
2. You explicitly refresh the metadata via REST API call.
3. Dremio refreshes its catalog at query time.

The last option will make query planning more expensive, but you can try that out to see how much it impacts your performance.