Jonathan Ellis created CASSANDRA-11206: ------------------------------------------
Summary: Support large partitions on the 3.0 sstable format Key: CASSANDRA-11206 URL: https://issues.apache.org/jira/browse/CASSANDRA-11206 Project: Cassandra Issue Type: Improvement Reporter: Jonathan Ellis Fix For: 3.x Cassandra saves a sample of IndexInfo objects that store the offset within each partition of every 64KB (by default) range of rows. To find a row, we binary search this sample, then scan the partition of the appropriate range. The problem is that this scales poorly as partitions grow: on a cache miss, we deserialize the entire set of IndexInfo, which both creates a lot of GC overhead (as noted in CASSANDRA-9754) but is also non-negligible i/o activity (relative to reading a single 64KB row range) as partitions get truly large. We introduced an "offset map" in CASSANDRA-10314 that allows us to perform the IndexInfo bsearch while only deserializing IndexInfo that we need to compare against, i.e. log(N) deserializations. -- This message was sent by Atlassian JIRA (v6.3.4#6332)