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https://issues.apache.org/jira/browse/DRILL-6204?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16383861#comment-16383861
 ] 

ASF GitHub Bot commented on DRILL-6204:
---------------------------------------

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

    https://github.com/apache/drill/pull/1146#discussion_r171912800
  
    --- Diff: 
contrib/storage-hive/core/src/main/java/org/apache/drill/exec/store/hive/HiveDrillNativeScanBatchCreator.java
 ---
    @@ -174,7 +174,7 @@ public ScanBatch getBatch(ExecutorFragmentContext 
context, HiveDrillNativeParque
         // If there are no readers created (which is possible when the table 
is empty or no row groups are matched),
         // create an empty RecordReader to output the schema
         if (readers.size() == 0) {
    -      readers.add(new HiveDefaultReader(table, null, null, columns, 
context, conf,
    +      readers.add(new HiveDefaultReader(table, null, null, newColumns, 
context, conf,
    --- End diff --
    
    Could we rename newColumns -> nonPartitionedColumns or tableColumns?


> Pass tables columns without partition columns to empty Hive reader
> ------------------------------------------------------------------
>
>                 Key: DRILL-6204
>                 URL: https://issues.apache.org/jira/browse/DRILL-6204
>             Project: Apache Drill
>          Issue Type: Bug
>          Components: Storage - Hive
>    Affects Versions: 1.12.0
>            Reporter: Arina Ielchiieva
>            Assignee: Arina Ielchiieva
>            Priority: Major
>             Fix For: 1.13.0
>
>
> When {{store.hive.optimize_scan_with_native_readers}} is enabled, 
> {{HiveDrillNativeScanBatchCreator}} is used to read data from Hive tables 
> directly from file system. In case when table is empty or no row group are 
> matched, empty {{HiveDefaultReader}} is called to output the schema.
> If such situation happens, currently Drill fails with the following error:
> {noformat}
> org.apache.drill.common.exceptions.UserRemoteException: SYSTEM ERROR: 
> NullPointerException Setup failed for null 
> {noformat}
> This happens because instead of passing only table columns to the empty 
> reader (as we do when creating non-empty reader), we passed all columns which 
> may contain partition columns as well. Readers fails to find partition column 
> in table schema. As mentioned in on lines 81 - 82 in 
> {{HiveDrillNativeScanBatchCreator}}, we deliberately separate out partition 
> columns and table columns to pass partition columns separately:
> {noformat}
>       // Separate out the partition and non-partition columns. Non-partition 
> columns are passed directly to the
>       // ParquetRecordReader. Partition columns are passed to ScanBatch.
> {noformat}
> To fix the problem we need to pass table columns instead of all columns.
> {code:java}
>     if (readers.size() == 0) {
>       readers.add(new HiveDefaultReader(table, null, null, newColumns, 
> context, conf,
>         ImpersonationUtil.createProxyUgi(config.getUserName(), 
> context.getQueryUserName())));
>     }
> {code}



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