When i was using Apache iBatis and Spring together, i got some weird exception for a long time.
It was,

"UnCategorizedSQLException" without any information in its SQL code or SQL state. That is SQL code is -999 and SQL state is null i think. I am not so sure of what i got. But this is the scenario.

I tried so many ways to fix it, i tried tuning my multi threads and changed the library jar files. But nothing helped me to sort out the problem.

After a long googling, my friend told me that frequent calling of select queries in iBatis makes it difficult run further queries. Its a known issue with iBatis with its caching mechanism.

So people facing these kind of problems, please try to reduce the number of frequent calling of select queries. Hope it will solve the issue.