kbendick edited a comment on pull request #3543:
URL: https://github.com/apache/iceberg/pull/3543#issuecomment-985818457


   > Just to resonate with what Russell said, I have also heard a few customers 
got confused about the caching behaviors, and not enabling caching directly 
would likely be a more straight-forward solution for users, compared to have a 
30 seconds expiration that we have to then explain potential behaviors of query 
based on this expiration time.
   > 
   > Overall I think it's worth adding the feature, Trino and Presto also has 
something similar like `hive.metastore-refresh-interval`. I would personally 
just do not set a default for that config, given it is an optional config 
anyway.
   > 
   > Given the fact that the PR is also getting quite messy with all the 
changes, I would say let's first add the `cache-enabled` as a catalog property 
with `true` as default, which is the default behavior today. Then we can add 
time-based expiration and review it separately in more details.
   
   So you think I should open a new PR that just has a flag for 
`expiration-enabled`, @jackye1995? Or can we keep the current 
`cache.expiration-interval-ms` but turn it off by default (set to -1 or zero)?
   
   There is a `cache-enabled` flag already.
   
   It's also worth noting that Spark has added a similar feature, where it 
expires table relations from the session catalog's cache after write. This was 
added in Spark 3.1: 
https://github.com/apache/spark/blob/38115cb907ec93151382260cda327330e78ca340/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala#L163-L172
   
   It is admittedly disabled by default though (but that's probably more for 
backwards compatability purposes): 
https://github.com/apache/spark/blob/fba61ad68bb12b22055d5d475e95e2681685eed7/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/StaticSQLConf.scala#L242-L252


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