The efficient comparators aren't always used except for BytesWritable and Text ------------------------------------------------------------------------------
Key: HADOOP-6881 URL: https://issues.apache.org/jira/browse/HADOOP-6881 Project: Hadoop Common Issue Type: Bug Affects Versions: 0.20.0 Reporter: Owen O'Malley Assignee: Owen O'Malley When we moved from Java 4 to Java 5 (and then 6), there was a change in the JVM semantics such that references to a class such as IntWritable.class no longer forces initialization. Since all of the Writables depend on their class static blocks to register their fast comparators, that can happen *after* we look up the comparator. In that case, the framework will fall back to the generic comparator that deserializes both keys and does the object compare, which may cause a huge slow down in the sort. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.