Re: 12.2.0.1 scheduler tables not being purged

  • From: Sayan Malakshinov <xt.and.r@xxxxxxxxx>
  • To: "Beckstrom, Jeffrey" <jbeckstrom@xxxxxxxxx>
  • Date: Tue, 25 May 2021 18:04:57 +0300

What do you mean?
You will see delete statements, just compare their predicates with your old
logs and you'll see which predicates exclude your data.
For example, if you have rows with non-null dbid

Best regards,
Sayan Malakshinov
Oracle performance tuning expert
Oracle Database Developer Choice Award winner
Oracle ACE Associate
http://orasql.org

On Tue, May 25, 2021, 17:52 Beckstrom, Jeffrey <jbeckstrom@xxxxxxxxx> wrote:

I’m not sure if a trace will tell WHY certain rows ARE being deleted and
OTHERS are NOT.



*From:* Sayan Malakshinov <xt.and.r@xxxxxxxxx>
*Sent:* Tuesday, May 25, 2021 10:22 AM
*To:* Beckstrom, Jeffrey <jbeckstrom@xxxxxxxxx>
*Cc:* Karthikeyan Panchanathan <keyantech@xxxxxxxxx>;
oracle-l@xxxxxxxxxxxxx
*Subject:* Re: 12.2.0.1 scheduler tables not being purged



Hi Jeffrey,



That's pretty easy to investigate:

1. execute purge job:

SQL> exec Dbms_scheduler.run_job('PURGE_LOG');

2. find DELETEs from SYS.SCHEDULER$ tables:
https://github.com/xtender/xt_scripts/blob/master/find_sql.sql
<https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fxtender%2Fxt_scripts%2Fblob%2Fmaster%2Ffind_sql.sql&data=04%7C01%7Cjbeckstrom%40gcrta.org%7C573d45b138fb41146d2a08d91f8889d7%7Cebe8e20736ec47f48cb8f5f757605f5d%7C1%7C0%7C637575494595062396%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=hBKdaooXyzlwq4jg22i9SWf2fgKxb5biI8%2BKFwsZOkE%3D&reserved=0>

(or you can trace it with sql_trace level 1 and get them from a trace file)



SQL> @find_sql "DELETE%SCHEDULER$%" all



it will return a few SQL_IDs:

INST_ID SQL_ID         EXECS   ELAEXE SQL_TEXT_TRUNC
------- ------------- ------ -------- -------------------------------------
      1 1xcngwj6ypnkx      1  .010972 DELETE FROM
SYS.SCHEDULER$_JOB_RUN_...
      1 7kvy2vdfs9ffv      1  .005409 DELETE FROM
SYS.SCHEDULER$_EVENT_LO...
      1 av3n8cwad6f2n      1  .003241 DELETE FROM
SYS.SCHEDULER$_EVENT_LO...
      1 bycc25ggkmbmw      1  .003204 DELETE FROM
SYS.SCHEDULER$_WINDOW_D...



[I've shortened the output to make it more readable]



3. Get their full text:

1xcngwj6ypnkx:
DELETE FROM SYS.SCHEDULER$_JOB_RUN_DETAILS
WHERE LOG_ID IN (
  SELECT E.LOG_ID
  FROM SYS.SCHEDULER$_EVENT_LOG E,
       SYS.SCHEDULER$_CLASS C
  WHERE E.TYPE# = 66
    AND E.CLASS_ID = C.OBJ#(+)
    AND (E.FLAGS IS NULL OR BITAND(E.FLAGS, 2)=0)
    AND OPERATION NOT LIKE 'CHAIN%'
    AND E.LOG_DATE < :B2 - NUMTODSINTERVAL(NVL(C.LOG_HISTORY, :B1 ), 'DAY')
)
/
7kvy2vdfs9ffv
DELETE FROM SYS.SCHEDULER$_EVENT_LOG
WHERE DBID IS NULL
  AND LOG_ID IN (
      SELECT E.LOG_ID
      FROM SYS.SCHEDULER$_EVENT_LOG E,
           SYS.SCHEDULER$_CLASS C
      WHERE E.TYPE# = 66
        AND E.CLASS_ID = C.OBJ#(+)
        AND (E.FLAGS IS NULL OR BITAND(E.FLAGS, 2)=0)
        AND OPERATION NOT LIKE 'CHAIN%'
        AND E.LOG_DATE < :B2 - NUMTODSINTERVAL(NVL(C.LOG_HISTORY, :B1 ),
'DAY')
      )
/
av3n8cwad6f2n:
DELETE FROM SYS.SCHEDULER$_EVENT_LOG
WHERE DBID IS NULL
AND LOG_ID IN (
           SELECT E.LOG_ID
           FROM SYS.SCHEDULER$_EVENT_LOG E
           WHERE E.TYPE# = 69
           AND E.LOG_DATE < :B2 - NUMTODSINTERVAL(:B1 , 'DAY')
           )
/

[I have formatted them...]



4. So you can now analyze why these queries do not delete your old data.

For example, sql_id: av3n8cwad6f2n "DELETE FROM SYS.SCHEDULER$_EVENT_LOG
WHERE DBID IS NULL ..." deletes only rows where DBID is null and type#=69,
so you can check your DBID and TYPE#:

select dbid, type#, count(*)

from SYS.SCHEDULER$_EVENT_LOG

group by dbid, type#;



etc...



On Tue, May 25, 2021 at 4:52 PM Beckstrom, Jeffrey <jbeckstrom@xxxxxxxxx>
wrote:

Looks like very recent information is purging but not all information.
Checked several databases and all doing something similar.



select trunc(log_date),count(*) from sys.dba_scheduler_job_run_details
group by trunc(log_date) order by 1





TRUNC(LOG
COUNT(*)

--------- ----------

These go back to 2011

02-JUN-20         16


03-JUN-20
18

04-JUN-20
18

05-JUN-20
16

06-JUN-20
106

07-JUN-20
112

08-JUN-20
     16

09-JUN-20
18

10-JUN-20
18

11-JUN-20         17


12-JUN-20
18

13-JUN-20
106

14-JUN-20        111


15-JUN-20
18

16-JUN-20
16

17-JUN-20         18


18-JUN-20
13

19-JUN-20
16

20-JUN-20         11


21-JUN-20
102

22-JUN-20
18

23-JUN-20
16

24-JUN-20
18

25-JUN-20
18

26-JUN-20
16

27-JUN-20         11        - from here on looks like
purging

25-APR-21
4

26-APR-21
8

27-APR-21          8


28-APR-21
8

29-APR-21
8

30-APR-21
8

01-MAY-21
10

02-MAY-21
9

03-MAY-21
      8

04-MAY-21
8

05-MAY-21
8

06-MAY-21         11



*From:* Beckstrom, Jeffrey
*Sent:* Tuesday, May 25, 2021 8:09 AM
*To:* Karthikeyan Panchanathan <keyantech@xxxxxxxxx>;
oracle-l@xxxxxxxxxxxxx
*Subject:* RE: 12.2.0.1 scheduler tables not being purged



The attached shows no rows from June 28, 2020 to April 24, 2021 so some
data is being purged.Howver there is a lot of data from June 27, 2020 and
earlier.



*From:* Beckstrom, Jeffrey
*Sent:* Tuesday, May 25, 2021 7:43 AM
*To:* Karthikeyan Panchanathan <keyantech@xxxxxxxxx>;
oracle-l@xxxxxxxxxxxxx
*Subject:* RE: 12.2.0.1 scheduler tables not being purged



Select * from dba_scheduler_global_attribute ;



ATTRIBUTE_NAME


--------------------------------------------------------------------------------

VALUE


--------------------------------------------------------------------------------

MAX_JOB_SLAVE_PROCESSES





LOG_HISTORY

30



DEFAULT_TIMEZONE

US/Eastern



LAST_OBSERVED_EVENT





EVENT_EXPIRY_TIME





CURRENT_OPEN_WINDOW





EMAIL_SERVER





EMAIL_SERVER_ENCRYPTION

NONE



EMAIL_SERVER_CREDENTIAL





EMAIL_SENDER





FILE_WATCHER_COUNT

0





11 rows selected.



*From:* Beckstrom, Jeffrey
*Sent:* Tuesday, May 25, 2021 7:33 AM
*To:* Karthikeyan Panchanathan <keyantech@xxxxxxxxx>;
oracle-l@xxxxxxxxxxxxx
*Subject:* RE: 12.2.0.1 scheduler tables not being purged



There is no object called dba_shcheduler_global_Attirbute.



The scheduler shows “purge_log” as running with no failures.



*From:* Karthikeyan Panchanathan <keyantech@xxxxxxxxx>
*Sent:* Monday, May 24, 2021 4:32 PM
*To:* Beckstrom, Jeffrey <jbeckstrom@xxxxxxxxx>; oracle-l@xxxxxxxxxxxxx
*Subject:* Re: 12.2.0.1 scheduler tables not being purged



Dbms_scheduler.run_job(‘PURGE_LOG’)



That should purge job log.



Please check dba_shcheduler_global_Attirbute where
attribute_name=‘LOG_HISTORY’ to see log history value







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------------------------------

*From:* oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx> on
behalf of Beckstrom, Jeffrey <jbeckstrom@xxxxxxxxx>
*Sent:* Monday, May 24, 2021 2:45:42 PM
*To:* oracle-l@xxxxxxxxxxxxx <oracle-l@xxxxxxxxxxxxx>
*Subject:* 12.2.0.1 scheduler tables not being purged



What purges the scheduler tables? We are seeing entries going back to
2011. The sys owned purge_log job does show as being scheduled with no
failures.





select min (log_date) from dba_scheduler_job_log;

MIN(LOG_DATE)
---------------------------------------------------------------------------
03-OCT-11 10.00.01.100000 PM -04:00



select min (log_date) from sys.SCHEDULER$_EVENT_LOG;

MIN(LOG_DATE)
---------------------------------------------------------------------------
03-OCT-11 10.00.01.100000 PM -04:00



Jeffrey Beckstrom

Greater Cleveland Regional Transit Authority

1240 W. 6th Street

Cleveland, Ohio 44113






--

Best regards,
Sayan Malakshinov

Oracle performance tuning engineer

Oracle ACE Associate
http://orasql.org
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