drill-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DRILL-3623) Hive query hangs with limit 0 clause
Date Tue, 17 Nov 2015 01:16:10 GMT

    [ https://issues.apache.org/jira/browse/DRILL-3623?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15007751#comment-15007751
] 

ASF GitHub Bot commented on DRILL-3623:
---------------------------------------

Github user jinfengni commented on a diff in the pull request:

    https://github.com/apache/drill/pull/193#discussion_r45010657
  
    --- Diff: exec/java-exec/src/main/java/org/apache/drill/exec/planner/logical/DrillDirectScanRel.java
---
    @@ -0,0 +1,111 @@
    +/**
    + * 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.exec.planner.logical;
    +
    +import com.google.common.collect.Iterators;
    +import org.apache.calcite.plan.RelOptCluster;
    +import org.apache.calcite.plan.RelTraitSet;
    +import org.apache.calcite.rel.AbstractRelNode;
    +import org.apache.calcite.rel.RelWriter;
    +import org.apache.calcite.rel.type.RelDataType;
    +import org.apache.drill.common.logical.data.LogicalOperator;
    +import org.apache.drill.exec.physical.base.PhysicalOperator;
    +import org.apache.drill.exec.planner.physical.DrillScanPrel;
    +import org.apache.drill.exec.planner.physical.PhysicalPlanCreator;
    +import org.apache.drill.exec.planner.physical.PlannerSettings;
    +import org.apache.drill.exec.planner.physical.Prel;
    +import org.apache.drill.exec.planner.physical.PrelUtil;
    +import org.apache.drill.exec.planner.physical.visitor.PrelVisitor;
    +import org.apache.drill.exec.record.BatchSchema;
    +import org.apache.drill.exec.store.direct.DirectGroupScan;
    +
    +import java.io.IOException;
    +import java.util.Iterator;
    +
    +/**
    + * Logical and physical RelNode representing a {@link DirectGroupScan}. This is not backed
by a {@link DrillTable},
    + * unlike {@link DrillScanRel}.
    + */
    +public class DrillDirectScanRel extends AbstractRelNode implements DrillScanPrel, DrillRel
{
    --- End diff --
    
    Sounds like that the DrillDirectScanRel approach works only when "limit 0" is on the root
level; it would not apply when "limit 0" is inside a subquery. 
    
    The Values approach may apply for the case "limit 0" in a subquery. Certainly, this JIRA
only targets the case of "limit 0" on root. But with the VALUES approach, there is room for
improvement for a more general scenarios. 
    



> Hive query hangs with limit 0 clause
> ------------------------------------
>
>                 Key: DRILL-3623
>                 URL: https://issues.apache.org/jira/browse/DRILL-3623
>             Project: Apache Drill
>          Issue Type: Bug
>          Components: Storage - Hive
>    Affects Versions: 1.1.0
>         Environment: MapR cluster
>            Reporter: Andries Engelbrecht
>            Assignee: Sudheesh Katkam
>             Fix For: Future
>
>
> Running a select * from hive.table limit 0 does not return (hangs).
> Select * from hive.table limit 1 works fine
> Hive table is about 6GB with 330 files with parquet using snappy compression.
> Data types are int, bigint, string and double.
> Querying directory with parquet files through the DFS plugin works fine
> select * from dfs.root.`/user/hive/warehouse/database/table` limit 0;



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message