[DERBY-1329] ASSERT failure/IndexOutOfBoundsException with correlated subquery for UPDATE ... SET ... WHERE CURRENT OF ... statement.

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 10.0.2.0, 10.0.2.1, 10.1.1.0, 10.1.2.1, 10.1.3.1, 10.2.1.6
• Fix Version/s: 10.1.3.1, 10.2.1.6
• Component/s: SQL
• Assignee: A B
• Reporter: A B
• Created: 17/May/06 01:17
• Updated: 09/Jun/06 03:57
• Resolved: 09/Jun/06 03:56

Description

If in a statement of the form "UPDATE ... SET ... WHERE CURRENT OF ..." the SET clause includes a correlated subquery that has a predicate referencing the table that is being updated, Derby will fail with an ASSERT failure in sane mode and an IndexOutOfBounds exception in insane mode.

For example, if we have a cursor CUR1 for the results of a SELECT query on BASICTABLE1, and then we try to execute the following update statement:

update BASICTABLE1 set C3 = (SELECT CC3 FROM
BASICTABLE2 WHERE BASICTABLE1.ID=BASICTABLE2.IID)
where current of CUR1

the result in SANE mode will be:

org.apache.derby.shared.common.sanity.AssertFailure: ASSERT FAILED tableNumber is expected to be non-negative.

and in INSANE mode will be:

java.lang.IndexOutOfBoundsException: bitIndex < 0: -1

The failure occurs during preprocessing of the subquery node when Derby is trying to "categorize" a predicate to see if it is pushable. The exact code is in ColumnReference.categorize():

public boolean categorize(JBitSet referencedTabs, boolean simplePredsOnly)

{ if (SanityManager.DEBUG) SanityManager.ASSERT(tableNumber >= 0, "tableNumber is expected to be non-negative"); referencedTabs.set(tableNumber); return ( ! replacesAggregate ) && ( (source.getExpression() instanceof ColumnReference) || (source.getExpression() instanceof VirtualColumnNode) || (source.getExpression() instanceof ConstantNode)); }

We get to this code for a ColumnReference who's tableNumber is -1, which means that, in sane mode, the assert will fire; in insane mode, we'll call "referencedTabs.set()" passing in a -1, which leads to the IndexOutOfBoundsException.

This failure occurs in embedded and with both clients, and occurs in 10.0, 10.1, and the 10.2 trunk.