[TAJO-674] ExplainLogicalPlan can cause NPE when a query includes derived tables

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Fix Version/s: 0.8.0, 0.9.0
• Component/s: Planner/Optimizer
• Assignee: Alvin Henrick
• Reporter: Hyunsik Choi
• Created: 07/Mar/14 02:33
• Updated: 02/Apr/14 01:05
• Resolved: 02/Apr/14 01:05

Description

The reproduction query is as follows:

SELECT distinct col1 FROM (SELECT * FROM col2 WHERE col3='2014-02-27') a

Addition information is that col3 is a partition key.

This query causes NPE as follows:

HTTP ERROR: 500
INTERNAL_SERVER_ERROR
RequestURI=/querydetail.jsp
Caused by:
java.lang.NullPointerException
at org.apache.tajo.engine.planner.BasicLogicalPlanVisitor.visitTableSubQuery(BasicLogicalPlanVisitor.java:230)
at org.apache.tajo.engine.planner.ExplainLogicalPlanVisitor.visitTableSubQuery(ExplainLogicalPlanVisitor.java:169)
at org.apache.tajo.engine.planner.ExplainLogicalPlanVisitor.visitTableSubQuery(ExplainLogicalPlanVisitor.java:29)
at org.apache.tajo.engine.planner.BasicLogicalPlanVisitor.visit(BasicLogicalPlanVisitor.java:93)
at org.apache.tajo.engine.planner.ExplainLogicalPlanVisitor.visitUnaryNode(ExplainLogicalPlanVisitor.java:115)
at org.apache.tajo.engine.planner.ExplainLogicalPlanVisitor.visitGroupBy(ExplainLogicalPlanVisitor.java:108)
at org.apache.tajo.engine.planner.ExplainLogicalPlanVisitor.visitGroupBy(ExplainLogicalPlanVisitor.java:29)
at org.apache.tajo.engine.planner.BasicLogicalPlanVisitor.visit(BasicLogicalPlanVisitor.java:75)
at org.apache.tajo.engine.planner.ExplainLogicalPlanVisitor.getBlockPlanStrings(ExplainLogicalPlanVisitor.java:71)
at org.apache.tajo.engine.planner.PlannerUtil.buildExplainString(PlannerUtil.java:701)
at org.apache.tajo.engine.planner.global.MasterPlan.toString(MasterPlan.java:263)
at org.apache.jsp.querydetail_jsp._jspService(org.apache.jsp.querydetail_jsp:231)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:109)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:389)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:486)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:380)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:363)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:417)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:534)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:864)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:533)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:207)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:403)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:522)