[ https://issues.apache.org/jira/browse/PIG-545?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Pradeep Kamath updated PIG-545: ------------------------------- Attachment: PIG-545-v4.patch Attached patch which addresses observation (1) in the previous comment. Regarding (2), the differences from the current SortPartitioner are: - In the configure of the WeightedRangePartitioner the entire sample file is loaded and a hash is built for those sample elements which repeat across partition boundaries - this is more expensive than previously but one time set up - IN the getPartition() call, if the input element is present in the hash, then probabilistically a partition is assigned based on the information in the hash else (as previously), a binary search of the quantiles array is done to figure out the partition - overall this should be nearly the same as previously performance wise. Regarding (3), getPartition() is a hadoop interface method and hence we cannot throw any other exception besides RuntimeException > PERFORMANCE: Sampler for order bys does not produce a good distribution > ----------------------------------------------------------------------- > > Key: PIG-545 > URL: https://issues.apache.org/jira/browse/PIG-545 > Project: Pig > Issue Type: Bug > Components: impl > Affects Versions: types_branch > Reporter: Alan Gates > Assignee: Pradeep Kamath > Fix For: types_branch > > Attachments: PIG-545-v3.patch, PIG-545-v4.patch, WRP.patch, WRP1.patch > > > In running tests on actual data, I've noticed that the final reduce of an > order by has skewed partitions. Some reduces finish in a few seconds while > some run for 20 minutes. Getting a better distribution should lead to much > better performance for order by. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.