Some customers have experienced problems with the new Ignite Top Plans feature. The symptoms of the problems are errors in the Ignite error log similar to:
Error retrieving Plan Hashes for batch 1: ORA-12152: TNS:unable to send break message
Other errors may accompany this problem and trace files may also be generated.
All versions of DPA
The workaround for this problem is to setup a logon trigger on the monitored database for the Ignite user to set a session level variable.
1. Pause the automatic monitor restart feature in the Ignite GUI. To do this, click the “Scheduler” button in the Ignite toolbar and change the “Repository Scheduling Status” setting to “Paused”.
2. Stop the Ignite monitor for the database
3. Log into the monitored database as SYSTEM (or some DBA user) and create the trigger with the code below.
4. Restart the monitor for the database and re-enable the automatic scheduler (opposite of Step 1).
CREATE OR REPLACE TRIGGER ignite_logon_trg
AFTER LOGON ON DATABASE
IF UPPER(USER) = UPPER(‘&IgniteUser’) THEN
EXECUTE IMMEDIATE ‘ALTER SESSION SET “_cursor_plan_unparse_enabled” = FALSE’;
The cause of the problem is Oracle Bug 6356566 that affects STATSPACK and other tools along with Ignite.