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https://issues.apache.org/jira/browse/DERBY-6750?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14152341#comment-14152341
]
Knut Anders Hatlen commented on DERBY-6750:
-------------------------------------------
The bug goes even further back, if you use an INNER JOIN instead of a NATURAL
JOIN:
{code:sql}
SELECT * FROM (
SELECT 1 AS X FROM SYSIBM.SYSDUMMY1
) Q1 INNER JOIN (
SELECT X FROM (
SELECT 1 AS X FROM SYSIBM.SYSDUMMY1
) Q2 UNION SELECT X FROM (
SELECT 2 AS X FROM SYSIBM.SYSDUMMY1
) Q3
) Q4 on Q1.X = Q4.X
{code}
The above query hangs all the way back to 10.2.1.6. It returns a result on
10.1.3.1. On 10.1.2.1 and earlier, it fails with a NullPointerException.
> Query parsing seems to hang forever in ColumnReference.getSourceResultSet
> -------------------------------------------------------------------------
>
> Key: DERBY-6750
> URL: https://issues.apache.org/jira/browse/DERBY-6750
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.11.1.1
> Reporter: Ralf Menzel
>
> We have an application that programmatically generates queries. For some
> queries the call of Connection.prepareStatement never returns. I took one of
> these queries and simplified until I got the following query:
> SELECT * FROM (
> SELECT 1 AS X FROM SYSIBM.SYSDUMMY1
> ) Q1 NATURAL JOIN (
> SELECT X FROM (
> SELECT 1 AS X FROM SYSIBM.SYSDUMMY1
> ) Q2 UNION SELECT X FROM (
> SELECT 2 AS X FROM SYSIBM.SYSDUMMY1
> ) Q3
> ) Q4;
> When I execute this query with ij it never produces a result.
> A typical stack trace of our application when it hangs starts like this:
> java.lang.Exception: test timed out after 250 milliseconds
> at
> org.apache.derby.impl.sql.compile.ColumnReference.getSourceResultSet(Unknown
> Source)
> at
> org.apache.derby.impl.sql.compile.BinaryRelationalOperatorNode.getScopedOperand(Unknown
> Source)
> at
> org.apache.derby.impl.sql.compile.Predicate.getPredScopedForResultSet(Unknown
> Source)
> at
> org.apache.derby.impl.sql.compile.SetOperatorNode.pushOptPredicate(Unknown
> Source)
> at org.apache.derby.impl.sql.compile.UnionNode.optimizeIt(Unknown
> Source)
> at
> org.apache.derby.impl.sql.compile.ProjectRestrictNode.optimizeIt(Unknown
> Source)
> at
> org.apache.derby.impl.sql.compile.OptimizerImpl.costPermutation(Unknown
> Source)
> at org.apache.derby.impl.sql.compile.SelectNode.optimize(Unknown Source)
> at
> org.apache.derby.impl.sql.compile.ProjectRestrictNode.optimizeIt(Unknown
> Source)
> at
> org.apache.derby.impl.sql.compile.OptimizerImpl.costPermutation(Unknown
> Source)
> at org.apache.derby.impl.sql.compile.SelectNode.optimize(Unknown Source)
> at
> org.apache.derby.impl.sql.compile.DMLStatementNode.optimizeStatement(Unknown
> Source)
> at
> org.apache.derby.impl.sql.compile.CursorNode.optimizeStatement(Unknown Source)
> at org.apache.derby.impl.sql.GenericStatement.prepMinion(Unknown Source)
> at org.apache.derby.impl.sql.GenericStatement.prepare(Unknown Source)
> at
> org.apache.derby.impl.sql.conn.GenericLanguageConnectionContext.prepareInternalStatement(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement20.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement30.<init>(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedPreparedStatement40.<init>(Unknown
> Source)
> at org.apache.derby.jdbc.Driver40.newEmbedPreparedStatement(Unknown
> Source)
> at org.apache.derby.impl.jdbc.EmbedConnection.prepareStatement(Unknown
> Source)
> ...
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