ORA-20200: The instance was shutdown between snapshots

ORA-20200: The instance was shutdown between snapshots

The AWR Report is only generated using snapshots from period that instance was Started. If any shutdown occurrs it break stats and AWR can’t generate a report comparing a period where stats belong a old Instance Startup.

This occurrs because Instance stats is not persistent accross reboots, (as the name says is a Instance), so all stats get reseted in every reboot.

When generating reports between hours is easy identify when instance was started, but when generating awr reports between many days this become a painfull task if instance was restarted multiples times during a desired period.

How to find the best Interval to Generate your AWR Reports?

set pagesize 1000

set linesize 1000

(or)

SET LINESIZE 200

SET PAGESIZE 200

UNDEF num_days

COL startup_time FOR a30

COL db_name FOR a10

COL snap_start FOR 9999999

COL snap_end FOR 9999999

COL start_interval FOR a25

COL end_interval FOR a25

COL range_interval FOR a40

COL qtd_snaps FOR 999

SELECT s.startup_time, di.instance_name, MIN(snap_id) snap_start, MAX(snap_id) snap_end, MIN(end_interval_time) start_interval, MAX(end_interval_time) end_interval, EXTRACT(DAY FROM(MAX(end_interval_time) ) - MIN(end_interval_time) ) || ' Days(s) ' || EXTRACT(HOUR FROM(MAX(end_interval_time) ) - MIN(end_interval_time) ) || ' Hour(s) ' || EXTRACT(MINUTE FROM(MAX(end_interval_time) ) - MIN(end_interval_time) ) || ' Minute(s) ' range_interval, MAX(snap_id) - MIN(snap_id) qtd_snaps FROM dba_hist_snapshot s, dba_hist_database_instance di WHERE di.dbid = s.dbid AND   di.instance_number = s.instance_number AND   end_interval_time > DECODE(&&num_days,0,TO_DATE('31-JAN-9999','DD-MON YYYY'),3.14,s.end_interval_time,TO_DATE(SYSDATE,'dd/mm/yyyy') - (&num_days - 1) ) GROUP BY s.startup_time, di.instance_name ORDER BY startup_time ASC;

STARTUP_TIME                   INSTANCE_NAME    SNAP_START SNAP_END START_INTERVAL            END_INTERVAL              RANGE_INTERVAL                           QTD_SNAPS

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

20-AUG-20 02.36.53.000 PM      MQMPROD                   1        4 20-AUG-20 03.30.09.329 PM 20-AUG-20 06.30.07.232 PM 0 Days(s) 2 Hour(s) 59 Minute(s)                 3

20-AUG-20 07.41.25.000 PM      MQMPROD                   5       14 20-AUG-20 07.52.26.815 PM 21-AUG-20 02.31.00.607 AM 0 Days(s) 6 Hour(s) 38 Minute(s)                 9

22-AUG-20 02.05.58.000 AM      MQMPROD                  15       36 22-AUG-20 02.16.38.541 AM 22-AUG-20 01.00.12.251 PM 0 Days(s) 10 Hour(s) 43 Minute(s)               21

In above output is easy identify what SNAP_ID to use without keep trying and getting ORA-20200 or by reading a huge list of snaps.

The above query is NOT valid to get SNAP_ID to generate AWR Global RAC Report.