PRB: MS Oracle Driver 1.0 Limitation in MTS Environment

• Microsoft Transaction Server 1.0
• Microsoft Visual C++, 32-bit Editions, version 5.0

SYMPTOMS

When the Microsoft Oracle ODBC driver version 1.0 (build 2.00.006325) is used, concurrent queries performed by objects in the same Microsoft Transaction Server (MTS) package may exhibit slow performance.

CAUSE

Version 1.0 of the Microsoft Oracle ODBC driver is thread safe at the driver level. The ODBC driver can only handle one request at a time. This means that only one MTS client can access the driver at a time while the others wait. If multiple clients are simultaneously trying to run queries, performance may be slow. If the queries are long or there are a lot of clients, performance could be seriously impacted.

MTS assigns a separate thread to each client activity. Only one thread can access the driver at a time while the others must wait for the current request to finish. This is an issue for other multithreaded environments such as Internet Information Server (IIS) as well.

NOTE: This article assumes that the Oracle ODBC driver is being used in separate non-transactional MTS components.

RESOLUTION

Currently there is no workaround for the problem.

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Keywords          : TSrvODBC TSrvProg
Technology        : odbc
Version           : WINNT:1.0,5.0
Platform          : winnt
Issue type        : kbprb