Scheduler

How to Resolve ORA-27492: unable to run job: scheduler unavailable

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Error ORA-27492 Found error ORA-27492 when executed a tuning job. BEGIN   SYS.DBMS_SCHEDULER.RUN_JOB     (job_name             => ‘SYS.SQLTUNE_JOB_61535_2043’     ,use_current_session  => FALSE); END; Error at line 2 ORA-27492: unable to run job “SYS”.”SQLTUNE_JOB_61535_2043″: scheduler unavailable ORA-06512: in “SYS.DBMS_ISCHED”, line 209 ORA-06512: in “SYS.DBMS_SCHEDULER”, line 594 ORA-06512: in line 2 […]
PFILE and SPFILE

Where is the Location of PFILE?

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If we were trying to change parameters in an unfamiliar database that was handed over from other DBA, we have to figure it out whether the database started with SPFILE or PFILE. Moreover, if PFILE is used, you have to know the location of PFILE. Of course, we can ask the former DBA for the […]
Administration

How to Resolve ORA-00001: unique constraint (PERFSTAT.STATS$SQL_SUMMARY_PK) violated

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STATSPACK ORA-00001 Login as PERFSTAT and took a snapshot like the following statement. But it failed with ORA-00001. SQL> exec statspack.snap(i_snap_level=>5); BEGIN statspack.snap(i_snap_level=>5); END; * ERROR at line 1: ORA-00001: unique constraint (PERFSTAT.STATS$SQL_SUMMARY_PK) violated ORA-06512: at “PERFSTAT.STATSPACK”, line 1361 ORA-06512: at “PERFSTAT.STATSPACK”, line 2442 ORA-06512: at “PERFSTAT.STATSPACK”, line 91 ORA-06512: at line 1 This is […]
Administration

How to Suspend an Oracle Session

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Given a session was consuming lots of resource on Oracle database server, what should we do about the session? Killing the session might be an option for DBA, but all the uncommitted transactions will be rolled back and there could be no one knows how to continue the job.Set the target PID for debug.SQL> oradebug […]
Administration

How to Know Everything about an Unfamiliar Database

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In an unfamiliar environment, if there’s only oracle or grid account is available for DBA to use, how can he to know everything about the database in a short time?StandaloneFor a standalone, you can do this:Oracle Home[oracle@test ~]$ echo $ORACLE_HOME/u01/app/oracle/product/11.2.0Oracle SID (Instance Name)[oracle@test ~]$ echo $ORACLE_SIDORCLIf there’s no $ORACLE_SID, you may check smon, the background process […]
Initialization Parameter

When UNDO_RETENTION is Useless, When is Not

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At times, you may find out or feel that UNDO_RETENTION is useless at all. Raising the number of seconds cannot resolve ORA-01555. This is true under some specific conditions. Here I quote the requisites from the official document below: Fix-sized Undo Tablespace The UNDO_RETENTION parameter is ignored for a fixed size undo tablespace. The database […]
Auditing

Why Enable Unified Audit Trail in 12c

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In my opinion, the reason in short is that the unified audit systematically unify all required audit operations into a single, consolidated fashion.According Oracle 12c documentation, you can see what UA is about.The unified audit trail, which resides in a read-only table in the AUDSYS schema in the SYSAUX tablespace, makes this information available in […]