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Aleksey Yeschenko commented on CASSANDRA-4565: ---------------------------------------------- bq. Not sure how this will work if a total column with a shorter total shadows a title column with a longer ttl. Then lost update might be an issue. Or a column with tll shadowing a regular column with no ttl at all. This ttl change will be lost. I'm certain that nothing can be done about it. Turning them into tombstones is an option though. [~jbellis] there is a solution for 4542, but only because we know that if a row is in the memtable it can't exist in any of the sstables. I can implement that at least. > TTL columns with older then gcgrace do not need to flush > -------------------------------------------------------- > > Key: CASSANDRA-4565 > URL: https://issues.apache.org/jira/browse/CASSANDRA-4565 > Project: Cassandra > Issue Type: Improvement > Reporter: Edward Capriolo > Assignee: Aleksey Yeschenko > Fix For: 1.3 > > Attachments: cassandra-4565.patch.1.txt > > > With memcache many people are willing to sacrifice durability for > performance. Cassandra has a TimeToLive feature that can be used in caching > scenarios with low values for gc_grace_seconds. However from a code dive it > seems that cassandra will always write TTL to disk, even those that are > beyond gc_grace_seconds. If a use case very large memtables,small ttl, and > small gc_grace it is possible that flushing these columns to disk can be > skipped entirely in some scenarios. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira