[ https://issues.apache.org/jira/browse/CASSANDRA-2589?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis resolved CASSANDRA-2589. --------------------------------------- Resolution: Fixed Fix Version/s: (was: 0.8.2) 1.0 Thanks, committed v2. > row deletes do not remove columns > --------------------------------- > > Key: CASSANDRA-2589 > URL: https://issues.apache.org/jira/browse/CASSANDRA-2589 > Project: Cassandra > Issue Type: Improvement > Components: Core > Reporter: Aaron Morton > Assignee: Aaron Morton > Priority: Minor > Fix For: 1.0 > > Attachments: > 0001-remove-deleted-columns-before-flushing-memtable-v07-2.patch, > 0001-remove-deleted-columns-before-flushing-memtable-v07.patch, > 0001-remove-deleted-columns-before-flushing-memtable-v08-2.patch, > 0001-remove-deleted-columns-before-flushing-memtable-v08.patch > > > When a row delete is issued CF.delete() sets the localDeletetionTime and > markedForDeleteAt values but does not remove columns which have a lower time > stamp. As a result: > # Memory which could be freed is held on to (prob not too bad as it's already > counted) > # The deleted columns are serialised to disk, along with the CF info to say > they are no longer valid. > # NamesQueryFilter and SliceQueryFilter have to do more work as they filter > out the irrelevant columns using QueryFilter.isRelevant() > # Also columns written with a lower time stamp after the deletion are added > to the CF without checking markedForDeletionAt. > This can cause RR to fail, will create another ticket for that and link. This > ticket is for a fix to removing the columns. > Two options I could think of: > # Check for deletion when serialising to SSTable and ignore columns if the > have a lower timestamp. Otherwise leave as is so dead columns stay in memory. > # Ensure at all times if the CF is deleted all columns it contains have a > higher timestamp. > ## I *think* this would include all column types (DeletedColumn as well) as > the CF deletion has the same effect. But not sure. > ## Deleting (potentially) all columns in delete() will take time. Could track > the highest timestamp in the CF so the normal case of deleting all cols does > not need to iterate. > -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira