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https://issues.apache.org/jira/browse/DRILL-6204?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Arina Ielchiieva updated DRILL-6204:
------------------------------------
    Description: 
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}

  was:
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. 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}


> 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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