update column_index_size_in_kb description
Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/93c27549 Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/93c27549 Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/93c27549 Branch: refs/heads/cassandra-2.0 Commit: 93c27549a3b6ad8445bd0ff2c9f5ce3bd9357c2c Parents: dc7d5a0 Author: Jonathan Ellis <jbel...@apache.org> Authored: Wed Jul 16 16:17:29 2014 -0500 Committer: Jonathan Ellis <jbel...@apache.org> Committed: Wed Jul 16 16:17:34 2014 -0500 ---------------------------------------------------------------------- conf/cassandra.yaml | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/93c27549/conf/cassandra.yaml ---------------------------------------------------------------------- diff --git a/conf/cassandra.yaml b/conf/cassandra.yaml index f067635..c8064d1 100644 --- a/conf/cassandra.yaml +++ b/conf/cassandra.yaml @@ -421,13 +421,15 @@ auto_snapshot: true tombstone_warn_threshold: 1000 tombstone_failure_threshold: 100000 -# Add column indexes to a row after its contents reach this size. -# Increase if your column values are large, or if you have a very large -# number of columns. The competing causes are, Cassandra has to -# deserialize this much of the row to read a single column, so you want -# it to be small - at least if you do many partial-row reads - but all -# the index data is read for each access, so you don't want to generate -# that wastefully either. +# Granularity of the collation index of rows within a partition. +# Increase if your rows are large, or if you have a very large +# number of rows per partition. The competing goals are these: +# 1) a smaller granularity means more index entries are generated +# and looking up rows withing the partition by collation column +# is faster +# 2) but, Cassandra will keep the collation index in memory for hot +# rows (as part of the key cache), so a larger granularity means +# you can cache more hot rows column_index_size_in_kb: 64