[DERBY-4688] With Derby 10.6 and higher, selecting object columns from system tables ERROR XN020: Error marshalling or unmarshalling a user defined type

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 10.7.1.1
• Component/s: Network Client
• Labels: derby_triage10_9
• Urgency: Low
• Issue & fix info: Release Note Needed, Repro attached, Workaround attached
• Bug behavior facts: Embedded/Client difference, Regression
• Assignee: Unassigned
• Reporter: Katherine Marsden
• Created: 02/Jun/10 23:49
• Updated: 10/Jul/12 18:50

Description

If derby.jar is not in the classpath when a client selects an object from a system table, for example selecting ALIASINFO from SYS.SYSALIASES an error will result, eg.
ERROR XN020: Error marshalling or unmarshalling a user defined type: org.apache.
derby.catalog.types.RoutineAliasInfo

To reproduce, put only derbyclient.jar and derbytools.jar in your classpath and connect to a running server and run:
ij> connect 'jdbc:derby://localhost:1527/wombat;create=trrue';
ij> select * from sys.sysaliases
> > ;
ALIASID |ALIAS

SCHEMAID

JAVACLASSNAME

&

&

SYST&

ALIASINFO

SPECIFICNAME

--------------------------------------------------------------------------------
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ERROR XN020: Error marshalling or unmarshalling a user defined type: org.apache.
derby.catalog.types.RoutineAliasInfo
ij>

With the 10.5 client it gives the text of the procedure or function definition for ALIASINFO may have been useful to someone, e.g.
SQLCAMESSAGE(IN SQLCODE INTEGER,IN SQLERRML SMALLINT,IN SQLERRMC VARCHAR(2400),I
N SQLERRP CHAR(8),IN SQLERRD0 INTEGER,IN SQLERR&

I am not sure what can or should be done about this issue. Workaround include:

• Cast the value to LONG VARCHAR in the query.
• Put the server jars in the classpath if you want to use the objects.
• Remove extraneous columns if they are not used.

I am not sure what can or should be done about this issue, but a release note would at least help mitigate it.

Issue Links

• is related to: DERBY-4691 The Reference Guide should say that SYSCOLPERMS.COLUMNS and SYSCOLUMNS.COLUMNDEFAULT are not part of Derby's public api
• relates to: DERBY-5852 dblook fails with client if derby.jar is not in classpath with java.sql.SQLException: Error marshalling or unmarshalling a user defined type
• relates to: DERBY-4491 The network client changes UDTs into Strings and returns their type as LONGVARBINARY.