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Re: Log switch query

From: Howard J. Rogers <howardjr_at_www.com>
Date: Fri, 6 Oct 2000 10:39:33 +1000
Message-ID: <39dd11cb@news.iprimus.com.au>

"Wolfgang Kremser" <wolfang.kremser_at_colt.at> wrote in message news:bk0D5.5$tZ4.120_at_stuart.coltnet.at...
> in my opinion the checkpoint interval is too short ... its in the
> initXXX.ora defined
>
> greetings Wolfgang

That may well be, but issuing a checkpoint doesn't force a log switch (though the converse is of course true).

As for the original question?

Well, a quick glance at the alert log shows you switch redo logs every three minutes or so, which is way, way, way too often. Your log members (all of them) to be much bigger to slow that down to something approaching a more reasonable logswitch per half hour, or per hour etc. Given that they are currently only 5Mb big (if I can read correctly, which is often problematic), you should be looking at re-creating your logfiles at around 50 to 75Mb or even larger, and then dropping the old ones.

When you're switching at a reasonable frequency, see what is happening to your archive sizes then.

I can't think of anything that will force a log switch other than the extra things you mentioned, but when the redo subsystem is being put under stress like this, who knows what is going on. Sort that out first, and then see what's happening.

Regards
HJR
>
> Mike Hartas <michael.hartas_at_pancredit.com> wrote in message
> news:8ri17s$2i7$1_at_nnrp1.deja.com...
> > Hi,
> > What can force a log switch other than redo log filling or an alter
> > system switch logfile?. reason I asked is I'm looking at a list of
> > achived logs and only every other one seems to be the size of a redo
> > log. the alert log dosn`t show any alter system commands. what is going
> > on ?
> >
> > Cheers, Mike.
> >
> > archive dir sample -
> > -rw-r----- 1 oracle dba 5243392 Oct 5 13:38 PANL1_41717.dbf
> > -rw-r----- 1 oracle dba 2008064 Oct 5 13:40 PANL1_41718.dbf
> > -rw-r----- 1 oracle dba 5243392 Oct 5 13:43 PANL1_41719.dbf
> > -rw-r----- 1 oracle dba 1871872 Oct 5 13:45 PANL1_41720.dbf
> > -rw-r----- 1 oracle dba 5243392 Oct 5 13:49 PANL1_41721.dbf
> > -rw-r----- 1 oracle dba 1413120 Oct 5 13:50 PANL1_41722.dbf
> >
> > alert log sample -
> >
> > Completed database checkpoint by background
> > Thu Oct 5 13:35:03 2000
> > ARCH: Archival stopped
> > Thu Oct 5 13:35:03 2000
> > Beginning database checkpoint by background
> > Thu Oct 5 13:35:03 2000
> > Thread 1 advanced to log sequence 41717
> > Current log# 3 seq# 41717 mem#
> > 0: /gbmdclp1/oradata4/PANL/redo/PANLlog_3_1.dbf
> > Current log# 3 seq# 41717 mem#
> > 1: /gbmdclp1/oradata5/PANL/redo/PANLlog_3_2.dbf
> > Current log# 3 seq# 41717 mem#
> > 2: /gbmdclp1/oradata6/PANL/redo/PANLlog_3_3.dbf
> > Thu Oct 5 13:35:05 2000
> > ARCH: Archival started
> > Thu Oct 5 13:35:07 2000
> > Completed database checkpoint by background
> > Thu Oct 5 13:38:25 2000
> > Beginning database checkpoint by background
> > Thu Oct 5 13:38:25 2000
> > Thread 1 advanced to log sequence 41718
> > Current log# 2 seq# 41718 mem#
> > 0: /gbmdclp1/oradata4/PANL/redo/PANLlog_2_1.dbf
> > Current log# 2 seq# 41718 mem#
> > 1: /gbmdclp1/oradata5/PANL/redo/PANLlog_2_2.dbf
> > Current log# 2 seq# 41718 mem#
> > 2: /gbmdclp1/oradata6/PANL/redo/PANLlog_2_3.dbf
> > Thu Oct 5 13:38:26 2000
> > Completed database checkpoint by background
> > Thu Oct 5 13:40:02 2000
> > ARCH: Archival stopped
> > Thu Oct 5 13:40:03 2000
> > Beginning database checkpoint by background
> > Thu Oct 5 13:40:03 2000
> > Thread 1 advanced to log sequence 41719
> > Current log# 1 seq# 41719 mem#
> > 0: /gbmdclp1/oradata4/PANL/redo/PANLlog_1_1.dbf
> > Current log# 1 seq# 41719 mem#
> > 1: /gbmdclp1/oradata5/PANL/redo/PANLlog_1_2.dbf
> > Current log# 1 seq# 41719 mem#
> > 2: /gbmdclp1/oradata6/PANL/redo/PANLlog_1_3.dbf
> > Thu Oct 5 13:40:04 2000
> > ARCH: Archival started
> > Thu Oct 5 13:40:06 2000
> > Completed database checkpoint by background
> > Thu Oct 5 13:43:21 2000
> > Beginning database checkpoint by background
> > Thu Oct 5 13:43:21 2000
> > Thread 1 advanced to log sequence 41720
> > Current log# 3 seq# 41720 mem#
> > 0: /gbmdclp1/oradata4/PANL/redo/PANLlog_3_1.dbf
> > Current log# 3 seq# 41720 mem#
> > 1: /gbmdclp1/oradata5/PANL/redo/PANLlog_3_2.dbf
> > Current log# 3 seq# 41720 mem#
> > 2: /gbmdclp1/oradata6/PANL/redo/PANLlog_3_3.dbf
> > Thu Oct 5 13:43:25 2000
> > Completed database checkpoint by background
> > Thu Oct 5 13:45:02 2000
> > ARCH: Archival stopped
> > Thu Oct 5 13:45:03 2000
> > Beginning database checkpoint by background
> > Thu Oct 5 13:45:03 2000
> > Thread 1 advanced to log sequence 41721
> > Current log# 2 seq# 41721 mem#
> > 0: /gbmdclp1/oradata4/PANL/redo/PANLlog_2_1.dbf
> > Current log# 2 seq# 41721 mem#
> > 1: /gbmdclp1/oradata5/PANL/redo/PANLlog_2_2.dbf
> > Current log# 2 seq# 41721 mem#
> > 2: /gbmdclp1/oradata6/PANL/redo/PANLlog_2_3.dbf
> > Thu Oct 5 13:45:05 2000
> > ARCH: Archival started
> > Thu Oct 5 13:45:05 2000
> > Completed database checkpoint by background
> > Thu Oct 5 13:49:10 2000
> > Beginning database checkpoint by background
> > Thu Oct 5 13:49:10 2000
> > Thread 1 advanced to log sequence 41722
> > Current log# 1 seq# 41722 mem#
> > 0: /gbmdclp1/oradata4/PANL/redo/PANLlog_1_1.dbf
> > Current log# 1 seq# 41722 mem#
> > 1: /gbmdclp1/oradata5/PANL/redo/PANLlog_1_2.dbf
> > Current log# 1 seq# 41722 mem#
> > 2: /gbmdclp1/oradata6/PANL/redo/PANLlog_1_3.dbf
> > Thu Oct 5 13:49:12 2000
> > Completed database checkpoint by background
> > Thu Oct 5 13:50:02 2000
> > ARCH: Archival stopped
> > Thu Oct 5 13:50:03 2000
> > Beginning database checkpoint by background
> > Thu Oct 5 13:50:03 2000
> > Thread 1 advanced to log sequence 41723
> > Current log# 3 seq# 41723 mem#
> > 0: /gbmdclp1/oradata4/PANL/redo/PANLlog_3_1.dbf
> > Current log# 3 seq# 41723 mem#
> > 1: /gbmdclp1/oradata5/PANL/redo/PANLlog_3_2.dbf
> > Current log# 3 seq# 41723 mem#
> > 2: /gbmdclp1/oradata6/PANL/redo/PANLlog_3_3.dbf
> > Thu Oct 5 13:50:06 2000
> > ARCH: Archival started
> > Thu Oct 5 13:50:08 2000
> > Completed database checkpoint by background
> >
> >
> >
> >
> >
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>
>
Received on Thu Oct 05 2000 - 19:39:33 CDT

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