declare i number := 0; begin for c1 in ( select address, hash_value, sql_id from v$sql where last_active_time < sysdate - 1/24 and executions < 2 ) loop begin dbms_shared_pool.purge(c1.
address || ' ' || to_char(c1.hash_value), 'C'); i := i + 1; exception when others then dbms_output.put_line(c1.sql_ id); end; end loop; dbms_output.put_line('Cursors purged = ' || to_char(i)); end; /
I had faced some occourrences of this error in a 188.8.131.52 database recently.
ORA-07445: exception encountered: core dump [nstimexp()+45] [SIGSEGV] [ADDR:0x58] [PC:0x7F42ABB] [Address not mapped to object] 
After some investigation I found a match to Bug 3934729.
This issue is originally to matched to Bug 6918493, that is a reintroduction of Bug 2752985 but it’s fixed in 184.108.40.206.
However, on upgrading to 220.127.116.11 it’s a hit on Bug 3934729 which is fixed in 18.104.22.168.
Recommended actions are:
– Upgrade databases do 22.214.171.124 or higher. (best solution, but may require more efforts to validate the upgrade).
– Apply Patch 3934729: RANDOM ORA-07445 CORE DUMPS FROM DATABASE AND ORA-3113 FROM APPLICATION
– Set sqlnet.expire_time=0 (workaround)
– Ignore error.
After some research I decided to apply workaround, based on recommended usage of sqlnet.expire_time (Next weeks post is about this parameter :)).
This might be the root cause for the ORA-03135: connection lost contact and the actual value of this parameter on environment was 1, which is a very low value.
So, check which action is more suitable for your environment!
Hope it helps 🙂
Below some additional informations on my situation: