Transaction size limit & Data Truncation

Hello,

I use the PostgreSQL 7.0.2 JDBC Driver.

I can see that very long transaction are not supported. Is there any
limit in the transaction size?

My second querstion is about data truncation. As I can see postgresql
JDBC driver doesn't report a DataTruncation warning when  a data
value is truncated. Is there any other way to detect data truncation?

Thanks in advance for your help.

Best Regards,
Sofia Alexaki