HIVE-10341 : CBO (Calcite Return Path): TraitSets not correctly propa…

…gated in HiveSortExchange causes Assertion error (Jesus Camacho Rodriguez via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/cbo@1673837 13f79535-47bb-0310-9956-ffa450edef68

ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/reloperators/HiveSortExchange.java

@@ -1,6 +1,5 @@
 package org.apache.hadoop.hive.ql.optimizer.calcite.reloperators;
 
-import org.apache.calcite.plan.Convention;
 import org.apache.calcite.plan.RelOptCluster;
 import org.apache.calcite.plan.RelTraitSet;
 import org.apache.calcite.rel.RelCollation;
@@ -33,9 +32,8 @@ public static HiveSortExchange create(RelNode input,
       RelDistribution distribution, RelCollation collation) {
     RelOptCluster cluster = input.getCluster();
     distribution = RelDistributionTraitDef.INSTANCE.canonize(distribution);
-    RelTraitSet traitSet =
-        input.getTraitSet().replace(Convention.NONE).replace(distribution);
     collation = RelCollationTraitDef.INSTANCE.canonize(collation);
+    RelTraitSet traitSet = RelTraitSet.createEmpty().plus(distribution).plus(collation);
     return new HiveSortExchange(cluster, traitSet, input, distribution, collation);
   }