[ http://issues.apache.org/jira/browse/HADOOP-54?page=comments#action_12422673 ] Owen O'Malley commented on HADOOP-54: -------------------------------------
One more thing, the "append" isn't appending bytes, but a preserialized key/value pair. The interface is a little unfortunate, because it forces the key and value to be in the same buffer. A more general interface would be something like: append(byte[] key, int keyOffset, int keyLength, byte[] value, int valueOffset, int valueLength) The advantage of that interface is that if the application has the key and value in different buffers they don't need to be copied into a single buffer before being copied to the SequenceFile.Writer's buffer. > SequenceFile should compress blocks, not individual entries > ----------------------------------------------------------- > > Key: HADOOP-54 > URL: http://issues.apache.org/jira/browse/HADOOP-54 > Project: Hadoop > Issue Type: Improvement > Components: io > Affects Versions: 0.2.0 > Reporter: Doug Cutting > Assigned To: Arun C Murthy > Fix For: 0.5.0 > > Attachments: VIntCompressionResults.txt > > > SequenceFile will optionally compress individual values. But both > compression and performance would be much better if sequences of keys and > values are compressed together. Sync marks should only be placed between > blocks. This will require some changes to MapFile too, so that all file > positions stored there are the positions of blocks, not entries within > blocks. Probably this can be accomplished by adding a > getBlockStartPosition() method to SequenceFile.Writer. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
