[DERBY-3033] select query results in nullpointer exception in skipScan()

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.2.2.0
• Fix Version/s: 10.3.2.1, 10.4.1.3
• Component/s: SQL
• Environment: Windows XP, Java 5.0, JDBC, Derby 10.2.2.0
• Bug behavior facts: Regression
• Assignee: Bryan Pendleton
• Reporter: Haolan Qin
• Created: 29/Aug/07 20:35
• Updated: 21/Jan/11 17:50
• Resolved: 06/Oct/07 02:58

Description

The following error was repeatedly thrown when we tried to run a select query via JDBC. Strangely, the exact same select query did not trigger any error when run from the command line console. After we added an index, the error went away completely.

java.lang.NullPointerException
at org.apache.derby.impl.sql.execute.NoPutResultSetImpl.skipScan(Unknown Source)
at org.apache.derby.impl.sql.execute.TableScanResultSet.openCore(Unknown Source)
at org.apache.derby.impl.sql.execute.IndexRowToBaseRowResultSet.openCore(Unknown Source)
at org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.openCore(Unknown Source)
at org.apache.derby.impl.sql.execute.JoinResultSet.openRight(Unknown Source)
at org.apache.derby.impl.sql.execute.JoinResultSet.openCore(Unknown Source)
at org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.openCore(Unknown Source)
at org.apache.derby.impl.sql.execute.SortResultSet.openCore(Unknown Source)
at org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.openCore(Unknown Source)
at org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.open(Unknown Source)
at org.apache.derby.impl.sql.GenericPreparedStatement.execute(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedStatement.executeStatement(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedPreparedStatement.executeStatement(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedPreparedStatement.execute(Unknown Source)
at org.apache.derby.impl.drda.DRDAStatement.execute(Unknown Source)
at org.apache.derby.impl.drda.DRDAConnThread.processCommands(Unknown Source)
at org.apache.derby.impl.drda.DRDAConnThread.run(Unknown Source)

Issue Links

• is related to: DERBY-1357 Short-circuit logic in optimizer appears to be incorrect...
• relates to: DERBY-4798 NPE in nested outer join
• relates to: DERBY-3097 Unnecessary if statement can be removed from BaseActivation.getColumnFromNow