Yu-Wen Lai created IMPALA-10801:
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             Summary: Check the latest compaction Id before serving request
                 Key: IMPALA-10801
                 URL: https://issues.apache.org/jira/browse/IMPALA-10801
             Project: IMPALA
          Issue Type: Improvement
          Components: Catalog
            Reporter: Yu-Wen Lai
            Assignee: Yu-Wen Lai


Cache compaction Id for a given table/file-metadata in CatalogD.

Whenever there is a read request to CatalogD, get the latest compaction event 
Id from HMS, compare it with what is cached in CatalogD, and based on that 
decide whether to serve the data from cache or to refresh it from the 
filesystem. This can avoid notification based cache invalidation.

Also, since there will be an open txn for the current long running query which 
is being served from CatalogD, we can be sure that current file-metadata being 
served is not already deleted by the cleaner.

This proposal will use a new HMS APIĀ 
(https://issues.apache.org/jira/browse/HIVE-24828) to get the latest compaction 
id for a table.



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