[DRILL-4984] Limit 0 raises NullPointerException on JDBC storage sources

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.0, 1.9.0, 1.10.0, 1.11.0, 1.12.0
• Fix Version/s: 1.15.0
• Component/s: Query Planning & Optimization

Environment

Latest 1.9 release also 1.8 release version,
mysql-connector-java-5.1.30, mysql-connector-java-5.1.40

• Assignee: Vitalii Diravka
• Reporter: Holger Kiel
• Created: 31/Oct/16 12:13
• Updated: 03/Dec/18 10:53
• Resolved: 03/Dec/18 10:53

Description

NullPointerExceptions occur when a query with 'limit 0' is executed on a jdbc storage source (e.g. Mysql):

0: jdbc:drill:zk=local> select * from mysql.sugarcrm.sales_person limit 0;
Error: SYSTEM ERROR: NullPointerException


[Error Id: 6cd676fc-6db9-40b3-81d5-c2db044aeb77 on localhost:31010]

  (org.apache.drill.exec.work.foreman.ForemanException) Unexpected exception during fragment initialization: null
    org.apache.drill.exec.work.foreman.Foreman.run():281
    java.util.concurrent.ThreadPoolExecutor.runWorker():1142
    java.util.concurrent.ThreadPoolExecutor$Worker.run():617
    java.lang.Thread.run():745
  Caused By (java.lang.NullPointerException) null
    org.apache.drill.exec.planner.sql.handlers.FindHardDistributionScans.visit():55
    org.apache.calcite.rel.core.TableScan.accept():166
    org.apache.calcite.rel.RelShuttleImpl.visitChild():53
    org.apache.calcite.rel.RelShuttleImpl.visitChildren():68
    org.apache.calcite.rel.RelShuttleImpl.visit():126
    org.apache.calcite.rel.AbstractRelNode.accept():256
    org.apache.calcite.rel.RelShuttleImpl.visitChild():53
    org.apache.calcite.rel.RelShuttleImpl.visitChildren():68
    org.apache.calcite.rel.RelShuttleImpl.visit():126
    org.apache.calcite.rel.AbstractRelNode.accept():256
    org.apache.drill.exec.planner.sql.handlers.FindHardDistributionScans.canForceSingleMode():45
    org.apache.drill.exec.planner.sql.handlers.DefaultSqlHandler.convertToDrel():262
    org.apache.drill.exec.planner.sql.handlers.DefaultSqlHandler.convertToDrel():290
    org.apache.drill.exec.planner.sql.handlers.DefaultSqlHandler.getPlan():168
    org.apache.drill.exec.planner.sql.DrillSqlWorker.getPhysicalPlan():123
    org.apache.drill.exec.planner.sql.DrillSqlWorker.getPlan():97
    org.apache.drill.exec.work.foreman.Foreman.runSQL():1008
    org.apache.drill.exec.work.foreman.Foreman.run():264
    java.util.concurrent.ThreadPoolExecutor.runWorker():1142
    java.util.concurrent.ThreadPoolExecutor$Worker.run():617
    java.lang.Thread.run():745 (state=,code=0)
0: jdbc:drill:zk=local> select * from mysql.sugarcrm.sales_person limit 1;
+-----+-------------+----------------+------------+-------------+
| id  | first_name  |   last_name    | full_name  | manager_id  |
+-----+-------------+----------------+------------+-------------+
| 1   | null        | Administrator  | admin      | 0           |
+-----+-------------+----------------+------------+-------------+
1 row selected (0,235 seconds)

Other datasources are okay:

0: jdbc:drill:zk=local> SELECT * FROM cp.`employee.json` LIMIT 0;
+------+-----------+-----------+---------+--------------+------------+-------------+------------+--------------+-----------------+-----------+----------------+-------------+------------+---------+----------------+------------------+-----------------+---------+------------------+
| fqn  | filename  | filepath  | suffix  | employee_id  | full_name  | first_name  | last_name  | position_id  | position_title  | store_id  | department_id  | birth_date  | hire_date  | salary  | supervisor_id  | education_level  | marital_status  | gender  | management_role  |
+------+-----------+-----------+---------+--------------+------------+-------------+------------+--------------+-----------------+-----------+----------------+-------------+------------+---------+----------------+------------------+-----------------+---------+------------------+
+------+-----------+-----------+---------+--------------+------------+-------------+------------+--------------+-----------------+-----------+----------------+-------------+------------+---------+----------------+------------------+-----------------+---------+------------------+
No rows selected (0,309 seconds)

Issue Links

• is superceded by: DRILL-6850 JDBC integration tests failures