We have recently migrated database from 10g to 188.8.131.52 enterprise edition and now we are facing slow performance issue on database .
Morever we have observed that paging size has increased to 90% which was around 20-30% before migration.
and also CPU increased to 100%.
RAM : 16gb
SWAP : 8gb
sga_target : 9gb
pga : 2.3gb
Did you check
Things to Consider Before Upgrading to 184.108.40.206 to Avoid Poor Performance or Wrong Results [ID 1392633.1]
Slow Performance in Pick Release After Upgrade to RDBMS 220.127.116.11 (11gr2) [ID 1087099.1]
What do the AWR reports look like for the time when you are experiencing slowness?
There is also a new [url http://www.ora00600.com/scripts/11g/10g-to-11g-upgrade.html]resource manager plan in 11g which caused me issues after upgrading from 10g to 11g.
We'll need more details to see exactly what is slow.
Pl also see
Things to Consider Before Upgrading to 18.104.22.168 to Avoid Poor Performance or Wrong Results [ID 1320966.1]
TROUBLESHOOTING: Server Upgrade Results in Slow Query Performance [ID 160089.1]
Query Performance Degradation - Upgrade Related - Recommended Actions [ID 745216.1]