MS SQL Server SelectMethod Performance

Question

I was having problems connecting to a MS SQL Server 2000 database using datasources.
With transactional operations, JDBC throws me the following exception:
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Can't start manual transaction mode because there are cloned connections.I found in the Internet that this issue wolud be solved setting the DataSource property selectMethod=cursor, but many people says that this configuration has many performance implications.
Can anyone tell me more about this issue???

Answer 1

Can you pin point a particular TopLink query tied to the " FETCH_APICURSOR* " call in the app and post how it is being created?
My guess is that the application is specifying the TopLink query object to return a cursor or stream and not closing it in all cases, or keeping them open for a long period - did you say they were leaking, or is it just that a large number are open at a time leading to performance problems?
This streams+cursors are described in the TopLink docs here
http://docs.oracle.com/cd/E21764_01/web.1111/b32441/qryadv.htm#CJGJBHGJ
or the 10g docs here:
http://sqltech.cl/doc/oas10gR3/web.1013/b13593/qryadv010.htm
If this is the case, you might want to use a different strategy such as pagination instead of cursors, described here:
http://docs.oracle.com/cd/E17904_01/web.1111/b32441/optimiz.htm#CHDIBGFE
Best Regards,
Chris