# When the value of "Refresh every" of Refresh Policy is smaller than "Expire after", will anything be triggered? or nothing happen?

**URL:** <https://community.dremio.com/t/when-the-value-of-refresh-every-of-refresh-policy-is-smaller-than-expire-after-will-anything-be-triggered-or-nothing-happen/7411>\
**Category:** Uncategorized\
**Created:** [May 6, 2021, 5:31am UTC](https://community.dremio.com/t/when-the-value-of-refresh-every-of-refresh-policy-is-smaller-than-expire-after-will-anything-be-triggered-or-nothing-happen/7411 "2021-05-06T05:31:38Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![roychen11232357](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/roychen11232357/32/3336_2.png) [@roychen11232357](https://community.dremio.com/u/roychen11232357)\
**Post date:** [May 6, 2021, 5:31am UTC](https://community.dremio.com/t/when-the-value-of-refresh-every-of-refresh-policy-is-smaller-than-expire-after-will-anything-be-triggered-or-nothing-happen/7411/1 "2021-05-06T05:31:38Z")

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As far as I know, whether it expires is based on the age of reflection, but if the value of refresh is less than expire, then the expire action will never be triggered.

I don’t know if my understanding is correct, please guide me, thanks a lot!

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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:** [May 6, 2021, 6:53am UTC](https://community.dremio.com/t/when-the-value-of-refresh-every-of-refresh-policy-is-smaller-than-expire-after-will-anything-be-triggered-or-nothing-happen/7411/2 "2021-05-06T06:53:19Z")

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@roychen11232357 That is correct, if your refreshes are working, you should not hit a condition where your reflection has expired

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**Author:** ![roychen11232357](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/roychen11232357/32/3336_2.png) [@roychen11232357](https://community.dremio.com/u/roychen11232357)\
**Post date:** [May 6, 2021, 7:08am UTC](https://community.dremio.com/t/when-the-value-of-refresh-every-of-refresh-policy-is-smaller-than-expire-after-will-anything-be-triggered-or-nothing-happen/7411/3 "2021-05-06T07:08:55Z")

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@balaji.ramaswamy  
Thank you for your reply, but I want to have a deeper understanding of the context in which the two parameters refresh and expire are used.

I list three situations

1. When refresh\> expire
2. When refresh \<expire
3. When refresh = expire

I can’t imagine that the combination of these three case is suitable for those actual scenarios

I hope you give me a simple situation, thank you very much

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<div class="post-metadata">

**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:** [May 7, 2021, 6:41am UTC](https://community.dremio.com/t/when-the-value-of-refresh-every-of-refresh-policy-is-smaller-than-expire-after-will-anything-be-triggered-or-nothing-happen/7411/4 "2021-05-07T06:41:27Z")

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@roychen11232357 You can never set expire \< refresh, thats not allowed, would not recommend setting refresh=expire as even if one background refresh fails, your dataset will expire causing an inline refresh

Recommend setting expire = 3x of refresh as that gives buffer for any possible metadata refresh failed or takes longer than the refresh interval defined