Mailing-List: contact derby-dev-help@db.apache.org; run by ezmlm
Precedence: bulk
Reply-To: <derby-dev@db.apache.org>
Message-ID: <4828378.1202579887871.JavaMail.jira@brutus>
Date: Sat, 9 Feb 2008 09:58:07 -0800 (PST)
From: "Bryan Pendleton (JIRA)" <jira@apache.org>
To: derby-dev@db.apache.org
Subject: [jira] Commented: (DERBY-3094) Grouping of expressions causes
 NullPointerException
In-Reply-To: <17254827.1191312770742.JavaMail.jira@brutus>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable


    [ https://issues.apache.org/jira/browse/DERBY-3094?page=3Dcom.atlassian=
.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D1256=
7336#action_12567336 ]=20

Bryan Pendleton commented on DERBY-3094:
----------------------------------------

Note that there are *two* ProjectRestrictResultSet instances in the tree:
 - the inner PRN operates on the bulk table scan, and projects columns
   "a" and "b" from table "xx" out of the table scan using projection "e1".
 - then the GroupedAggregateResultSet processes the rows, and
   computes the COUNT(*) into the 3rd column of the template row
 - then the outer PRN takes the grouped results and projects columns
   "a", "(expression)", and "COUNT(*)" out of the grouped result row.

At the instant of the crash, the outer PRN is performing that final
projection, and it is looking for a row from result set 2.

But this is wrong; it ought to be looking for a row from result set 1.

In the debugger, I can see that result set 1's current row is correct:
it has the right columns, with the right values.

I can also see that, *later* in projection method "e3", there is another
call to getColumnFromRow() which passes result set number 1.

So that seems like additional evidence that the core of the problem is
that projection method "e3" generated invalid code which is
trying to access result set 2 when it should have been accessing
result set 1.

Since the column in question is column 2, which is the expression
a*(b/100.000000), I'm wondering whether the inner PRN and the
outer PRN are somehow accidentally sharing the expression
information for this result column expression, when one of them should
have renumbered the result set for the expression to point to the
different result set.

This feels really familiar, like we just worked on some problems with
result set number handling and result column expressions recently;
I'll spend a bit of time searching JIRA to see if I can refresh that memory=
.


> Grouping of expressions causes NullPointerException
> ---------------------------------------------------
>
>                 Key: DERBY-3094
>                 URL: https://issues.apache.org/jira/browse/DERBY-3094
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 10.3.1.4
>         Environment: Windows XP, Eclipse 3.2.2, java 1.5.0.11
>            Reporter: Peter Balon
>            Assignee: Bryan Pendleton
>            Priority: Critical
>
> Following steps to reproduce the bug:
> create table xx (a double, b double);
> insert into xx values (2, 3);
> select a, a*(b/100.000000), count(*) from xx  group by a, a*(b/100.000000=
);
> Starting run
> select a, a*(b/100.000000), count(*) from xx=20
> group by a, a*(b/100.000000)
> Run successful
> SQL State =3D 38000 SQL Code =3D 20000 SQL Message =3D Bei der Auswertung=
 eines Ausdrucks wurde die Ausnahme 'java.lang.NullPointerException' ausgel=
=C3=B6st. Exception message =3D java.sql.SQLException: Bei der Auswertung e=
ines Ausdrucks wurde die Ausnahme 'java.lang.NullPointerException' ausgel=
=C3=B6st.
> Work around:
> select a, a*(b/100.000000), count(*) from xx group by a, b, a*(b/100.0000=
00)=20
> Stack trace from application:
> java.sql.SQLException: Bei der Auswertung eines Ausdrucks wurde die Ausna=
hme 'java.lang.NullPointerException' ausgel=C3=B6st.
> =09at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unkn=
own Source)
> =09at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source=
)
> =09at org.apache.derby.impl.jdbc.Util.seeNextException(Unknown Source)
> =09at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLExcepti=
on(Unknown Source)
> =09at org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(=
Unknown Source)
> =09at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown =
Source)
> =09at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown =
Source)
> =09at org.apache.derby.impl.jdbc.EmbedResultSet.closeOnTransactionError(U=
nknown Source)
> =09at org.apache.derby.impl.jdbc.EmbedResultSet.movePosition(Unknown Sour=
ce)
> =09at org.apache.derby.impl.jdbc.EmbedResultSet.next(Unknown Source)
> =09at de.arcor.billy.report.views.designer.ReportViewerView.setInput(Repo=
rtViewerView.java:255)
> =09at de.arcor.billy.report.views.designer.ReportViewerView.createPartCon=
trol(ReportViewerView.java:113)
> =09at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReferenc=
e.java:332)
> =09at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java=
:197)
> =09at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPar=
tReference.java:566)
> =09at org.eclipse.ui.internal.Perspective.showView(Perspective.java:1675)
> =09at org.eclipse.ui.internal.WorkbenchPage.busyShowView(WorkbenchPage.ja=
va:987)
> =09at org.eclipse.ui.internal.WorkbenchPage.access$13(WorkbenchPage.java:=
968)
> =09at org.eclipse.ui.internal.WorkbenchPage$13.run(WorkbenchPage.java:351=
4)
> =09at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:6=
7)
> =09at org.eclipse.ui.internal.WorkbenchPage.showView(WorkbenchPage.java:3=
511)
> =09at de.arcor.billy.report.data.ReportDataAdvisor$2.perspectiveChanged(R=
eportDataAdvisor.java:268)
> =09at de.arcor.billy.system.actions.AbstractOpenPerspectiveActionDelegate=
$1.run(AbstractOpenPerspectiveActionDelegate.java:66)
> =09at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
> =09at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.=
java:123)
> =09at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3325)
> =09at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2971)
> =09at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1930)
> =09at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1894)
> =09at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.j=
ava:422)
> =09at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149=
)
> =09at de.arcor.billy.product.Billy.run(Billy.java:15)
> =09at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformA=
ctivator.java:78)
> =09at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApp=
lication(EclipseAppLauncher.java:92)
> =09at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(=
EclipseAppLauncher.java:68)
> =09at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.=
java:400)
> =09at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.=
java:177)
> =09at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> =09at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> =09at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
> =09at java.lang.reflect.Method.invoke(Unknown Source)
> =09at org.eclipse.core.launcher.Main.invokeFramework(Main.java:336)
> =09at org.eclipse.core.launcher.Main.basicRun(Main.java:280)
> =09at org.eclipse.core.launcher.Main.run(Main.java:977)
> =09at org.eclipse.core.launcher.Main.main(Main.java:952)
> Caused by: java.sql.SQLException: Java-Ausnahme: ': java.lang.NullPointer=
Exception'.
> =09at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unkn=
own Source)
> =09at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source=
)
> =09at org.apache.derby.impl.jdbc.Util.javaException(Unknown Source)
> =09at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLExcepti=
on(Unknown Source)
> =09... 42 more
> Caused by: java.lang.NullPointerException
> =09at org.apache.derby.exe.ac9b638174x0115x5f93x1332x0000046fd8a01b.e10(U=
nknown Source)
> =09at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> =09at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> =09at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
> =09at java.lang.reflect.Method.invoke(Unknown Source)
> =09at org.apache.derby.impl.services.reflect.ReflectMethod.invoke(Unknown=
 Source)
> =09at org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.doProjec=
tion(Unknown Source)
> =09at org.apache.derby.impl.sql.execute.ProjectRestrictResultSet.getNextR=
owCore(Unknown Source)
> =09at org.apache.derby.impl.sql.execute.ScrollInsensitiveResultSet.getNex=
tRowFromSource(Unknown Source)
> =09at org.apache.derby.impl.sql.execute.ScrollInsensitiveResultSet.getNex=
tRowCore(Unknown Source)
> =09at org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.getNextRo=
w(Unknown Source)
> =09... 37 more

--=20
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.