Oracle: Slow connections
by Wolfram Saringer (2013-07-18)
last change: 2013-07-18
If connecting to an Oracle instance is slow but queries themselves are OK try tnsping. If that takes more than 100ms take
a look at your DNS configuration.
Check if name resolution works with all DNS servers configured in /etc/resolv.conf. Check for redundant domain entries as
well.
Another possible cause may be a large listener log file. Location can be found with 'lsnrctl status'