Expire after & never expire

I am not clear how the Never expire & expire after options work.

Got some details from the transcripts of this webinar.

I’m also stating that the reflection materialization expires and should no longer be used after its three hours full. That marks once the age of a reflection is three hours old, or has deprecated. That means that new queries that arrive, will not use that reflection. Some queries were already perhaps in flight and may still be used. When something becomes deprecated, we do not immediately delete it. We wait for queries to no longer be using that reflection. You should be aware of that because … When planning for disc space that’ll be used by the system. When you delete a reflection or when expire one, we have backgrounds that harvest it later when queries aren’t used anymore.

Does this mean the reflections are dropped and the dataset will not have any reflection or will Dremio refresh the reflection after expiry.

If I set Never refresh & Never expire what will be the behavior?
If I set Refresh every 1 hour & Never expire what will the behavior?

If this is documented please share the link.

Hi @unni

Never refresh / never expire is usually checked if you want to take control of reflection refreshes via REST API


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