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Jeff Jirsa commented on CASSANDRA-18134: ---------------------------------------- I think I've asked for downgradability for ~years, but Scott's proposal on the mailing list is a proposal not a decision, and the wiki has it in pending, and I haven't seen any other feature gated on downgradability. Is there a vote thread that asserts that's a policy instead of a preference? (I do agree this needs to land in at least a new minor, if not a new major, rather than a patch release, like 4.2 or 5.0, but I'm not aware of the project voting on downgradability as a general requirement for new work) > Improve handling of min/max clustering in sstable > ------------------------------------------------- > > Key: CASSANDRA-18134 > URL: https://issues.apache.org/jira/browse/CASSANDRA-18134 > Project: Cassandra > Issue Type: Improvement > Components: Local/SSTable > Reporter: Jacek Lewandowski > Assignee: Jacek Lewandowski > Priority: Normal > Fix For: 5.x > > > This patch improves the following things: > # SSTable metadata will store a covered slice instead of min/max clusterings. > The difference is that for slices there is available the type of a bound > rather than just a clustering. In particular it will provide the information > whether the lower and upper bound of an sstable is opened or closed. > # SSTable metadata will store a flag whether the SSTable contains any > partition level deletions or not > # The above two changes required to introduce a new major format for SSTables > - {{oa}} > # Single partition read command makes use of the above changes. In particular > an sstable can be skipped when it does not intersect with the column filter, > does not have partition level deletions and does not have statics; In case > there are partition level deletions, but the other conditions are satisfied, > only the partition header needs to be accessed (tests attached) > # Skipping sstables assuming those three conditions are satisfied has been > implemented also for partition range queries (tests attached). Also added > minor separate statistics to record the number of accessed sstables in > partition reads because now not all of them need to be accessed. That > statistics is also needed in tests to confirm skipping. > # Artificial lower bound marker is now an object on its own and is not > implemented as a special case of range tombstone bound. Instead it sorts > right before the lowest available bound in the data > # Extended the lower bound optimization usage due the 1 and 2 > # Do not initialize iterator just to get a cached partition and associated > columns index. The purpose of using lower bound optimization was to avoid > opening an iterator of an sstable if possible. > See also CASSANDRA-14861 > The changes in this patch include work of [~blambov], [~slebresne], > [~jakubzytka] and [~jlewandowski] -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org