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Home -> Community -> Mailing Lists -> Oracle-L -> RE: wait event:controlfile parallel write and sql*net more data f
He Dennis,
I can get a 100% hit ratio too!
See:
LOGICAL I/O PHYSICAL I/O BLOCK
USERNAME SYS_ID PROCESS BLOCKS BLOCKS CHANGES IDLE TIME
HITRATIO
OK, so it's only 99.98.
Here's how:
drop table c1;
drop table c2;
create table c1 as
select owner, table_name, tablespace_name
from dba_tables
where rownum < 10001
/
create table c2 as
select owner, table_name, tablespace_name
from dba_tables
where rownum < 10001
/
select
c1.owner
, c1.table_name
, c1.tablespace_name
, c2.owner
, c2.table_name
, c2.tablespace_name
from c1, c2
/
If I run this every 5 minutes from DBMS_JOB, I can keep my system Hit
Ratio
above 98%, and I won't need to do any tuning.
;^)
Jared
DENNIS WILLIAMS <DWILLIAMS_at_LIFETOUCH.COM>
Sent by: root_at_fatcity.com
08/06/2002 09:13 AM
Please respond to ORACLE-L
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
cc:
Subject: RE: wait event:controlfile parallel write and sql*net more data f
Chaos
Oracle continually writes to all copies of the control file. The thing
in
your report that jumps out at me is that you have zero (count 'em zero)
physical reads. You must have succeeded in caching all your data in
memory.
Congratulations. Also you seem to have few writes. My guess is that
controlfile parallel write is bubbling to the top in the absence of other
waits. Not a bad situation. You may want to look at add other disks in the
future, depending on how important recoverability is to this instance. If
you were to lose this disk, it might be difficult to recover this
database.
Dennis Williams
DBA
Lifetouch, Inc.
dwilliams_at_lifetouch.com
-----Original Message-----
Sent: Tuesday, August 06, 2002 10:39 AM
To: Multiple recipients of list ORACLE-L
from db-link.
hi, dbas:
I make a statspack report on one of my database and found a wait event that i did not see quite often.
This is a query intensive database, all 6 tables are snapshot from
a
master site and refresh every 1 hour.All other activity is query the
tables
and get a lot of data out of the database to middleware.
The following is the statspack,I looked at the Oracle reference
and
searched google for control file parallel write, but did not get much
valuable information.
Hope someone here can help me. Does this event really have adverse
impact on database performance, and how to tune it.I have three
controlfiles
on the same disk(only one disk in the server).
(One day activity)
Snap Id Snap Time Sessions
------- ------------------ --------
Begin Snap: 1238 06-Aug-02 10:43:39 30
End Snap: 1239 06-Aug-02 21:24:49 30
Elapsed: 641.17 (mins)
Cache Sizes
db_block_buffers: 156672 log_buffer: 2097152
db_block_size: 8192 shared_pool_size: 157286400
Load Profile
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: DENNIS WILLIAMS INET: DWILLIAMS_at_LIFETOUCH.COM Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: INET: Jared.Still_at_radisys.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Tue Aug 06 2002 - 13:28:24 CDT
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