[ https://issues.apache.org/jira/browse/PIG-627?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Richard Ding updated PIG-627: ----------------------------- Attachment: multiquery-phase3_0423.patch This patch completes the phase 3 development which merges multiple map-reduce aplittees into a splitter. As an example, the Pig script {code} A = load ... split A into B, beta ... C = filter B ... D = group C ... E = foreach D ... store E gamma = filter beta ... delta = group gamma ... epsilon = foreach delta ... store epsilon {code} discussed earlier in this bug now results in a single map-reduce job. This patch is for the multi query branch. > PERFORMANCE: multi-query optimization > ------------------------------------- > > Key: PIG-627 > URL: https://issues.apache.org/jira/browse/PIG-627 > Project: Pig > Issue Type: Improvement > Affects Versions: 0.2.0 > Reporter: Olga Natkovich > Attachments: doc-fix.patch, error_handling_0415.patch, > error_handling_0416.patch, file_cmds-0305.patch, fix_store_prob.patch, > merge-041409.patch, merge_741727_HEAD__0324.patch, > merge_741727_HEAD__0324_2.patch, merge_trunk_to_branch.patch, > multi-store-0303.patch, multi-store-0304.patch, multiquery-phase2_0313.patch, > multiquery-phase2_0323.patch, multiquery-phase3_0423.patch, > multiquery_0223.patch, multiquery_0224.patch, multiquery_0306.patch, > multiquery_explain_fix.patch, non_reversible_store_load_dependencies.patch, > non_reversible_store_load_dependencies_2.patch, > noop_filter_absolute_path_flag.patch, > noop_filter_absolute_path_flag_0401.patch, streaming-fix.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.