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https://issues.apache.org/jira/browse/IMPALA-8690?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Joe McDonnell reassigned IMPALA-8690:
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Assignee: Joe McDonnell
> Better eviction algorithm for data cache
> ----------------------------------------
>
> Key: IMPALA-8690
> URL: https://issues.apache.org/jira/browse/IMPALA-8690
> Project: IMPALA
> Issue Type: Improvement
> Components: Backend
> Affects Versions: Impala 3.3.0
> Reporter: Michael Ho
> Assignee: Joe McDonnell
> Priority: Major
>
> With the current implementation of data cache, all data access will be cached
> regardless of the access pattern. The current LRU eviction algorithm is not
> resistant to scan traffic so in case some users scan a big fact table, a lot
> of the heavily accessed items will be evicted inevitably. We should adopt
> better eviction algorithm (e.g. LRFU or some other well known ones in the
> literature). Would be nice to evaluate it against some users' traces now that
> IMPALA-8542 is fixed.
> In the short run, we probably need some workaround (e.g. query hints to
> disable caching for certain tables). Will file a separate jira for it.
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