[DRILL-276] aggregation over empty rowset will cause "Failure while running fragment. < NoSuchElementException"

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.4.0
• Assignee: Jinfeng Ni
• Reporter: Jinfeng Ni
• Created: 05/Nov/13 22:39
• Updated: 31/Jul/14 06:33
• Resolved: 29/May/14 15:44

Description

For the following query, the WHERE clause will produce 0 rows. If we apply the count() function over the 0 result rows, drill will fail with error.

SELECT count FROM "nation.parquet" where 1=0;

Here is the call stack when the NoSuchElementException is raised:

Seems that the SortRecordBatchBuilder does not have the code to handle empty rowset yet, which leads to the error.

java.util.NoSuchElementException
java.util.HashMap$HashIterator.nextEntry(HashMap.java:929) ~[na:1.7.0_45]
java.util.HashMap$EntryIterator.next(HashMap.java:966) ~[na:1.7.0_45]
java.util.HashMap$EntryIterator.next(HashMap.java:964) ~[na:1.7.0_45]
com.google.common.collect.AbstractMapBasedMultimap$KeySet$1.next(AbstractMapBasedMultimap.java:946) ~[guava-14.0.1.jar:na]
org.apache.drill.exec.physical.impl.sort.SortRecordBatchBuilder.build(SortRecordBatchBuilder.java:94) ~[drill-java-exec-1.0.0-m2-incubating-SNAPSHOT-rebuffed.jar:1.0.0-m2-incubating-SNAPSHOT]
org.apache.drill.exec.physical.impl.sort.SortBatch.next(SortBatch.java:138) ~[drill-java-exec-1.0.0-m2-incubating-SNAPSHOT-rebuffed.jar:1.0.0-m2-incubating-SNAPSHOT]
org.apache.drill.exec.physical.impl.aggregate.AggBatch.next(AggBatch.java:85) ~[drill-java-exec-1.0.0-m2-incubating-SNAPSHOT-rebuffed.jar:1.0.0-m2-incubating-SNAPSHOT]
org.apache.drill.exec.physical.impl.ScreenCreator$ScreenRoot.next(ScreenCreator.java:77) ~[drill-java-exec-1.0.0-m2-incubating-SNAPSHOT-rebuffed.jar:1.0.0-m2-incubating-SNAPSHOT]
org.apache.drill.exec.work.FragmentRunner.run(FragmentRunner.java:79) ~[drill-java-exec-1.0.0-m2-incubating-SNAPSHOT-rebuffed.jar:1.0.0-m2-incubating-SNAPSHOT]
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_45]
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_45]
java.lang.Thread.run(Thread.java:744) [na:1.7.0_45]

Issue Links

• is blocked by: DRILL-203 When you select a null field, things fail rather than returning null