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ASF GitHub Bot commented on DRILL-4743: --------------------------------------- Github user amansinha100 commented on a diff in the pull request: https://github.com/apache/drill/pull/534#discussion_r70495155 --- Diff: exec/java-exec/src/test/java/org/apache/drill/TestOptions.java --- @@ -0,0 +1,79 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.drill; + +import org.apache.drill.common.util.TestTools; +import org.junit.Test; + +import static org.junit.Assert.assertEquals; + +public class TestOptions extends BaseTestQuery { + static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(TestOptions.class); + + static final String WORKING_PATH = TestTools.getWorkingPath(); + static final String TEST_RES_PATH = WORKING_PATH + "/src/test/resources"; + private static final String EXPLAIN_PREFIX = "EXPLAIN PLAN FOR "; + private static final String EXPLAIN_WITH_ATTRIB_PREFIX = "EXPLAIN PLAN INCLUDING ATTRIBUTES FOR "; --- End diff -- Not used ? > HashJoin's not fully parallelized in query plan > ----------------------------------------------- > > Key: DRILL-4743 > URL: https://issues.apache.org/jira/browse/DRILL-4743 > Project: Apache Drill > Issue Type: Bug > Affects Versions: 1.5.0 > Reporter: Gautam Kumar Parai > Assignee: Gautam Kumar Parai > Labels: doc-impacting > > The underlying problem is filter selectivity under-estimate for a query with > complicated predicates e.g. deeply nested and/or predicates. This leads to > under parallelization of the major fragment doing the join. > To really resolve this problem we need table/column statistics to correctly > estimate the selectivity. However, in the absence of statistics OR even when > existing statistics are insufficient to get a correct estimate of selectivity > this will serve as a workaround. -- This message was sent by Atlassian JIRA (v6.3.4#6332)