cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Matthew F. Dennis (JIRA)" <>
Subject [jira] Commented: (CASSANDRA-1046) optimize Memtable.getSliceIterator
Date Fri, 04 Jun 2010 20:43:01 GMT


Matthew F. Dennis commented on CASSANDRA-1046:

sorry, "these changes" refer to 0001-trunk-cassandra-1046.patch

> optimize Memtable.getSliceIterator
> ----------------------------------
>                 Key: CASSANDRA-1046
>                 URL:
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Jonathan Ellis
>            Assignee: Matthew F. Dennis
>             Fix For: 0.7
>         Attachments: 0001-trunk-cassandra-1046.patch,,
> As reported by James Golick, about 30% of the time in a read is spent in SliceQueryFilter.getMemColumnIterator,
virtually all of which is in ConcurrentSkipListMap$Values.toArrray().
> I wrote on the ML:
> Besides the UUID optimization you posted, we should do an audit of ColumnFamily.getSortedColumns
and replace with iteration where possible (in this case, we'd be left with one copy of most
of the columns, but that's better than two).
> We can get rid of the other copy by fixing the logic in Memtable.getSliceIterator, which
says "copy all the columns, so we can do a binary search on them to find where to start,"
but since columns are natively in sorted order we could just use an iterator and a while loo

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message