Error ORA-12535: TNS:operation timed out has been occurring frequently since our database was converted to 9.2. The error manual suggests setting the CONNECT_TIMEOUT to 0 (for unlimited time to wait) and this was tried, but still the error. Next this parm was set to 60 (seconds) and still the error. The application is an ETL process which initiates from an NT machine, however, the databases are on Sun Solaris box.
Did you upgrade your client software on your Windows machine when you upgraded the database? You didn't specify your client software version, so you may want to look at upgrading it as well. This will most likely resolve your problem. Another thing to look at is to verify that any corporate firewall is not interferring with your connectivity.
If that does not solve your problem, then the only thing you can do is to generate a Net trace of your problem and upload it to Oracle Support. They will be able to identify the root cause of your problem.
Dig Deeper on Oracle database design and architecture
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.