Re: reads by KTSJ
Date: Wed, 13 May 2020 14:17:43 -0400
Message-ID: <CAMHX9JJnnL2+Zqdx1+STNSFutFvnSypd=TM13=V3Lp_enAV-YA_at_mail.gmail.com>
You mentioned that there were some *buffer busy waits* showing up too?
Instead of relying on the block address & DBA_EXTENTS query (maybe this
block has been reused by something else by now?), you can use ashtop to see
which *block class* the buffer busy waits were against. A random example
from my lab:
SQL> _at_ash/dashtop event*2 *"event='buffer busy waits'" sysdate-90 sysdate
Total
Also the *[ktspsc_segmon] submitted segfix task* messages in your
tracefiles are interesting.
SQL> SELECT description FROM x$ktsjtaskclass ORDER BY 1;
DESCRIPTION
Seconds AAS %This EVENT2
--------- ------- ------- ---------------------------------------------
38360 .0 88% buffer busy waits [*data block*]
4680 .0 11% buffer busy waits [*undo data*]
540 .0 1% buffer busy waits [*undo header*]
130 .0 0% buffer busy waits [*file header block*]
AIM scheduler
Affinitize segment for IM Hash Index
CLISLAVE
DROPTEMP
...
SEG DICT UPDATE
SYSAUX FILE OFFLINE CHECK
SYSAUX FILE ONLINE CHECK
*Segment Fixstate*
Segment Monitor
...
Indeed there's a KTSJ task class called "Segment Fixstate", so maybe Oracle's autonomously fixing something under the hood :)
--
Tanel
https://tanelpoder.com
--
http://www.freelists.org/webpage/oracle-l
Received on Wed May 13 2020 - 20:17:43 CEST