# External Reflection

**URL:** <https://community.dremio.com/t/external-reflection/4148>\
**Category:** Site Feedback\
**Created:** [September 23, 2019, 8:41am UTC](https://community.dremio.com/t/external-reflection/4148 "2019-09-23T08:41:25Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![dingbin](https://avatars.discourse-cdn.com/v4/letter/d/ecc23a/32.png) [@dingbin](https://community.dremio.com/u/dingbin)\
**Post date:** [September 23, 2019, 8:41am UTC](https://community.dremio.com/t/external-reflection/4148/1 "2019-09-23T08:41:25Z")

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My current version of Dremio is 3.2.8. Does Dremio3.2.8 having the feature of external reflection? And I had created external reflections, but I did not know how to cover the created external reflection. Can you write details on how to use external reflections? And if there is a regular acceleration flame icon or any more after using external reflections?

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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:** [September 24, 2019, 4:26am UTC](https://community.dremio.com/t/external-reflection/4148/2 "2019-09-24T04:26:39Z")

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Hi @dingbin

Did you go through this?

[https://docs.dremio.com/acceleration/creating-reflections.html#external-reflections](https://docs.dremio.com/acceleration/creating-reflections.html#external-reflections)

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**Author:** ![dingbin](https://avatars.discourse-cdn.com/v4/letter/d/ecc23a/32.png) [@dingbin](https://community.dremio.com/u/dingbin)\
**Post date:** [September 24, 2019, 4:58am UTC](https://community.dremio.com/t/external-reflection/4148/3 "2019-09-24T04:58:33Z")

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I created external reflections successfully follow this document. I used the query of “select \* from sys.reflections”, and found the external reflections I had created. But I didn’t know how to use this reflections. Can you describe this in details?

Thanks

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**Author:** ![dingbin](https://avatars.discourse-cdn.com/v4/letter/d/ecc23a/32.png) [@dingbin](https://community.dremio.com/u/dingbin)\
**Post date:** [September 24, 2019, 6:01am UTC](https://community.dremio.com/t/external-reflection/4148/4 "2019-09-24T06:01:01Z")

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I used the query of "  
CREATE VDS “@db”.“store\_sales\_tmp” AS  
SELECT  
AVG(ss\_quantity) average\_quantity,  
SUM(ss\_quantity) total\_quantity,  
COUNT(\*) sales\_count,  
ss\_sold\_date\_sk  
FROM “@db”.store\_sales  
GROUP BY ss\_sold\_date\_sk" to create the virtual dataset of store\_sales\_temp.  
And used the query of " ALTER DATASET “@db”.store\_sales\_temp

DROP EXTERNAL REFLECTION “external\_store\_sales\_temp”

USING “@db”.“store\_sales\_temp”" to create the external reflections of store\_sales\_temp successfully.

But when I run the query of “select \* from store\_sales\_temp”, the jobs history display that the external reflection can’t cover query. So what the issues I had met. Can you help me to solve this problem?

Thanks

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<div class="post-metadata">

**Author:** ![dingbin](https://avatars.discourse-cdn.com/v4/letter/d/ecc23a/32.png) [@dingbin](https://community.dremio.com/u/dingbin)\
**Post date:** [September 24, 2019, 6:07am UTC](https://community.dremio.com/t/external-reflection/4148/5 "2019-09-24T06:07:10Z")

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And I use the query of “select \* from sys.reflections” to inspect this external reflection, it display that the status is “OK”. But I see the other reflections such raw reflections’ status is “CAN\_ACCELERATE”. So any idea on this issue?

Thank you