[DERBY-1252] Old clients with new server return wrong database metadata values for some methods

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 10.1.1.0, 10.1.2.1, 10.1.3.1
• Fix Version/s: 10.2.1.6
• Component/s: JDBC, Network Client, Network Server
• Urgency: Urgent
• Bug behavior facts: Regression
• Assignee: Dag H. Wanvik
• Reporter: Dag H. Wanvik
• Created: 26/Apr/06 04:59
• Updated: 30/Jun/09 15:55
• Resolved: 03/Aug/06 20:37

Description

With an old client (10.1.1, 10.1.2) accessing a new (10.2) server,
some metadata calls will return the wrong value for both the JCC and
the Derby clients:

deletesAreDetected(TYPE_SCROLL_INSENSITIVE) -> true
updatedAreDetected(TYPE_SCROLL_INSENSITIVE) -> true
ownDeletesAreVisible(TYPE_SCROLL_INSENSITIVE) -> true
ownUpdatesAreVisible(TYPE_SCROLL_INSENSITIVE) -> true

This happens because these values were changed for the 10.2 with
the addition of updatable scrollable insensitive result sets (DERBY-775),
combined with a weakness in the way the client and the server
cooperates to answer these metadata calls.

Presently, when the client application invokes these methods, the
results will be returned by the server without regard to the identity
of the client, i.e. the 2-tuple

{JCC or Derby client, client version}

.
The values to be returned for the methods in question are based solely
on the values found in the file metadata_net.properties, which is part
of the server.

In general, some database metadata is dependent on the combination of
the capabilities in the client and the server and the returned values
should reflect this, which in general implies negotiating (down) to
values which are correct for the actual combination of client and
server.

Issue Links

• is related to: DERBY-965 DatabaseMetadata method supportsResultSetConcurrency returns wrong result on network client