[ https://issues.apache.org/jira/browse/IMPALA-12491?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Quanlong Huang updated IMPALA-12491: ------------------------------------ Attachment: impala_data_cache.png > Document whether the remote data cache has TTL > ---------------------------------------------- > > Key: IMPALA-12491 > URL: https://issues.apache.org/jira/browse/IMPALA-12491 > Project: IMPALA > Issue Type: Documentation > Reporter: Quanlong Huang > Priority: Major > Attachments: impala_data_cache.png > > > It's unclear to the users whether the remote data cache has TTL so will > expire after some time. We have document about the startup flags of remote > data cache, including the capacity and the eviction policy: > [https://impala.apache.org/docs/build/html/topics/impala_data_cache.html] > We should also mention that the cache item won't expire as long as the same > file metadata is used in the query. The reason is that the cache key is > (filename, mtime, file offset) where mtime is the last modified time of the > file. When the mtime in the file metadata doesn't change, the scan request > could always hit the cache (if capacity is enough). > CC [~shajini], [~joemcdonnell] -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org