library cache lock -history

Hello,

I am having the following issue:

*** 2015-08-02 10:17:11.230

DBMS_STATS: GATHER_STATS_JOB: GATHER_TABLE_STATS('"CMDB"','"TOPOLOGY_CHANGES_1"','""', ...)

DBMS_STATS: ORA-04021: timeout occurred while waiting to lock object.

I found the issue was actually a 'library cache lock' one.

from AWR new event in top 10:

Event                 Waits    Total Wait Time (sec)    Wait Avg(ms)    % DB time    Wait Class

library cache lock    2    1689.4                    844685              7.6            Concurrency <==

Foreground Wait Events

Event    Waits    %Time -outs    Total Wait Time (s)    Avg wait (ms)    Waits /txn    % DB time

direct path read    1,850,276    0    8,640    5    172.81    38.95

db file sequential read    682,004    0    2,240    3    63.70    10.10

library cache lock    2    50    1,689    844685    0.00    7.62  <===NEW EVENT