Rahul Challapalli created DRILL-5148: ----------------------------------------
Summary: Replace hash-distribution with a simple round-robin distribution for a simple order by query Key: DRILL-5148 URL: https://issues.apache.org/jira/browse/DRILL-5148 Project: Apache Drill Issue Type: Bug Components: Execution - Relational Operators, Query Planning & Optimization Affects Versions: 1.10.0 Reporter: Rahul Challapalli git.commit.id.abbrev=cf2b7c7 The below plan indicates that we use hash-distribution to avoid data skew. However in the below case a simple round-robin approach would be sufficient {code} explain plan for select * from dfs.`/drill/testdata/resource-manager/5kwidecolumns_500k.tbl` order by columns[0]; +------+------+ | text | json | +------+------+ | 00-00 Screen 00-01 Project(*=[$0]) 00-02 Project(T2¦¦*=[$0]) 00-03 SingleMergeExchange(sort0=[1 ASC]) 01-01 SelectionVectorRemover 01-02 Sort(sort0=[$1], dir0=[ASC]) 01-03 Project(T2¦¦*=[$0], EXPR$1=[$1]) 01-04 HashToRandomExchange(dist0=[[$1]]) 02-01 UnorderedMuxExchange 03-01 Project(T2¦¦*=[$0], EXPR$1=[$1], E_X_P_R_H_A_S_H_F_I_E_L_D=[hash32AsDouble($1)]) 03-02 Project(T2¦¦*=[$0], EXPR$1=[ITEM($1, 0)]) 03-03 Project(T2¦¦*=[$0], columns=[$1]) 03-04 Scan(groupscan=[EasyGroupScan [selectionRoot=maprfs:/drill/testdata/resource-manager/5kwidecolumns_500k.tbl, numFiles=1, columns=[`*`], files=[maprfs:///drill/testdata/resource-manager/5kwidecolumns_500k.tbl]]]) {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332)