# How to Refresh Reflection for a Specific VDS in Dremio

**URL:** <https://community.dremio.com/t/how-to-refresh-reflection-for-a-specific-vds-in-dremio/12954>\
**Category:** Uncategorized\
**Created:** [April 17, 2025, 10:37am UTC](https://community.dremio.com/t/how-to-refresh-reflection-for-a-specific-vds-in-dremio/12954 "2025-04-17T10:37:37Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![JoiceJacob](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/joicejacob/32/5715_2.png) [@JoiceJacob](https://community.dremio.com/u/JoiceJacob)\
**Post date:** [April 17, 2025, 10:37am UTC](https://community.dremio.com/t/how-to-refresh-reflection-for-a-specific-vds-in-dremio/12954/1 "2025-04-17T10:37:37Z")

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Hi team,

I’m using Dremio Community Edition v25.x. I have a setup where two VDS views (let’s call them `VDS_1` and `VDS_2`) are created from the same table (`test_table`). Then I created a final view (`VDS_FINAL`) as a `UNION ALL` of `VDS_1` and `VDS_2`. I have reflections enabled on : `VDS_1` and `VDS_2`.

From my understanding, reflection refresh is only possible at the physical table level. So, refreshing the reflection on `test_table` should automatically refresh the reflections on `VDS_1` and `VDS_2`.

However, is there a way to refresh the reflection **only** for a specific VDS (for example, just `VDS_2`) without refreshing the base table?

Thanks in advance!

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**Author:** ![balaji.ramaswamy](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/balaji.ramaswamy/32/843_2.png) [@balaji.ramaswamy](https://community.dremio.com/u/balaji.ramaswamy)\
**Post date:** [April 18, 2025, 5:39pm UTC](https://community.dremio.com/t/how-to-refresh-reflection-for-a-specific-vds-in-dremio/12954/2 "2025-04-18T17:39:49Z")

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@JoiceJacob VDS refresh feature is in 25.x

> **[ALTER VIEW | Dremio Documentation](https://docs.dremio.com/cloud/reference/sql/commands/alter-view/)**
>
> Change an existing view.

```auto
ALTER VIEW <view_name>
  [AT { REF[ERENCE] | BRANCH } <reference_name> ]
  { { ALTER | MODIFY | CHANGE } COLUMN <old_column_name> <new_column_name> <data_type>
  | ADD COLUMNS ( <column_name1> <data_type> [,...] )
  | DROP COLUMN <column_name>
  | { ADD | DROP } PARTITION FIELD { <column_name> | <partition_transform> }
  | CREATE EXTERNAL REFLECTION <reflection_name> USING <view_name>
  | CREATE AGGREGATE REFLECTION <reflection_name> USING  
    { DIMENSIONS ( <column_name1>, <column_name2>, ... )
    | MEASURES ( <column_name1> ( <aggregation_type>, <column_name2> <aggregation_type> , ... ) )
    | DIMENSIONS ( <column_name1>, <column_name2>, ... ) MEASURES ( <column_name1> ( <aggregation_type>, <column_name2> <aggregation_type> , ... ) ) }
    [PARTITION BY ( <column_name1>, <column_name2>, ... )]
    [LOCALSORT BY ( <column_name1>, <column_name2>, ... )]
  | CREATE RAW REFLECTION <reflection_name> USING DISPLAY ( <column_name1>, <column_name2>, ...)
    [PARTITION BY ( <column_name1>, <column_name2>, ... )]
    [LOCALSORT BY ( <column_name1>, <column_name2>, ... )]
  | DROP REFLECTION <reflection_name>
  | REFRESH REFLECTIONS
  | ROUTE REFLECTIONS TO { DEFAULT ENGINE | ENGINE { <engine_name> | <engine_uuid> } }

```

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<div class="post-metadata">

**Author:** ![JoiceJacob](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/joicejacob/32/5715_2.png) [@JoiceJacob](https://community.dremio.com/u/JoiceJacob)\
**Post date:** [April 19, 2025, 12:47pm UTC](https://community.dremio.com/t/how-to-refresh-reflection-for-a-specific-vds-in-dremio/12954/3 "2025-04-19T12:47:00Z")

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Hi @balaji.ramaswamy

Thank you for your response.  
Based on the document you shared:

1. I understand that it’s possible to refresh a specific VDS reflection using the Reflection API—please correct me if I’m mistaken.
2. Does the Reflection API (particularly for refreshing a specific VDS) work only in the Enterprise Edition, or is it also supported in the Community Edition?

Thanks in Advance !

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<div class="post-metadata">

**Author:** ![JoiceJacob](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/joicejacob/32/5715_2.png) [@JoiceJacob](https://community.dremio.com/u/JoiceJacob)\
**Post date:** [April 20, 2025, 6:01pm UTC](https://community.dremio.com/t/how-to-refresh-reflection-for-a-specific-vds-in-dremio/12954/4 "2025-04-20T18:01:12Z")

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Hi @balaji.ramaswamy

Can you please give an update on above points ?

Thanks in Advance

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**Author:** ![Benny\_Chow](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/benny_chow/32/5527_2.png) [@Benny\_Chow](https://community.dremio.com/u/Benny_Chow)\
**Post date:** [April 22, 2025, 3:15am UTC](https://community.dremio.com/t/how-to-refresh-reflection-for-a-specific-vds-in-dremio/12954/5 "2025-04-22T03:15:48Z")

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Refreshing a reflection from an anchor view is an EE feature. It’s really just a shortcut for finding all the physical datasets within the view and triggering a refresh from those physical datasets. The basic idea is that we want all reflections downstream from those physical datasets to be in a consistent state.