I have recently updated a 20+ year old PowerBuilder app that, before migration, was using an Oracle 7 driver to connect without issue to an Oracle 11 database. After switching to the ORA Oracle driver (the one meant for Oracle 11,12,19), it causes the application to hang and sometimes crash. My workaround is to just install and use the Oracle 10 driver. The application also performs faster with the O10 driver.
I'm looking for some tips on things I should be looking for to help better diagnose and ultimately fix this issue. I'm also using the Oracle 11 client and will be trying to upgrade both database and client to Oracle 19 soon.