[ http://issues.apache.org/jira/browse/HADOOP-54?page=comments#action_12430695 ] Arun C Murthy commented on HADOOP-54: -------------------------------------
Great... thanks Owen! PS: We should probably send a separate mail to hadoop-dev@ announcing the patch to build.xml to spare everyone a surprise... > 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: 0.6.0 > > Attachments: enum-54.patch, SequenceFile.20060821.patch, > SequenceFile.20060821.perfomance.txt, SequenceFile.20060822.tgz, > SequenceFile.updated.final.patch, SequenceFile20060824.tgz, > SequenceFiles.final.patch, SequenceFiles.patch, SequenceFilesII.patch, > 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
