[ https://issues.apache.org/jira/browse/PIG-627?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Gunther Hagleitner updated PIG-627: ----------------------------------- Attachment: multiquery_0224.patch This patch includes the multiquery unit test cases. > PERFORMANCE: multi-query optimization > ------------------------------------- > > Key: PIG-627 > URL: https://issues.apache.org/jira/browse/PIG-627 > Project: Pig > Issue Type: Improvement > Affects Versions: types_branch > Reporter: Olga Natkovich > Fix For: types_branch > > Attachments: multiquery_0223.patch, multiquery_0224.patch > > > Currently, if your Pig script contains multiple stores and some shared > computation, Pig will execute several independent queries. For instance: > A = load 'data' as (a, b, c); > B = filter A by a > 5; > store B into 'output1'; > C = group B by b; > store C into 'output2'; > This script will result in map-only job that generated output1 followed by a > map-reduce job that generated output2. As the resuld data is read, parsed and > filetered twice which is unnecessary and costly. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.