RE: Frequency of Log Switches

From: SAURY Alain <ASAURY_at_recherche.loreal.com>
Date: Thu, 30 Nov 2000 11:52:05 +0100
Message-Id: <10696.123304@fatcity.com>

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I beg to differ : I am running 8.1.6 on NT with log_checkpoint_timeout = =3D 300
and can have as much as 40 minutes between log switches.

I suppose that forcing a checkpoint does not forces a log switch = (whereas
the log switch forces the checkpoint).=20

Anybody having an idea on how to force a log switch ? Alain.

	-----Message d'origine-----
	De:	Kieran Murray [SMTP:Kieran.Murray_at_esat.com]
	Date:	jeudi 30 novembre 2000 10:46
	=C0:	Multiple recipients of list ORACLE-L
	Objet:	RE: Frequency of Log Switches

	Steven,

	try changing the initialization parameter LOG_CHECKPOINT_TIMEOUT to
be 900
	and set the LOG_CHECKPOINT_INTERVAL to be a very high value (greater
than
	the size of the redo logs),
	this will cause log switches every 15 minutes or when the log file
is full.
	Both of these values can=20
	be dynamically altered using ALTER SYSTEM.

	Regards,
	Kieran Murray
	Norkom Technologies,
	43 Upper Mount Street, Dublin 2, Ireland
	Tel:- +353 86 8117916

	-----Original Message-----
	Sent: 29 November 2000 22:03
	To: Multiple recipients of list ORACLE-L


	I know that the recommended optimal log switch interval is 30
minutes, and
	our log sizes of 20Mb average a little less than that.  Now that I
am
	looking to implement a standby database, my users have a requirement
that no
	more than 15 minutes of data should be lost if we need to fail over
to
	standby.  I was looking through the Oracle 8 reference (we are
running 8.0.5
	on SunOS 5.6) and I could not find one that would force a log switch
based
	on time, not size.  Is there one, or do I need to create a script
that
	simply forces a log switch every 15 minutes?

	TIA,
	-------------------------------------
	Steven Monaghan
	Oracle DBA
	MSC Industrial Direct Co., Inc.
	Melville, NY
	MonaghaS_at_mscdirect.com
	http://www.mscdirect.com
	-------------------------------------


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	Author: Steven Monaghan
	  INET: MonaghaS_at_mscdirect.com

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	--=20

	Author: Kieran Murray
	  INET: Kieran.Murray_at_esat.com

	Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
	San Diego, California        -- Public Internet access / Mailing
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I beg to differ=A0: I am running 8.1.6 = on NT with log_checkpoint_timeout =3D 300 and can have as much as 40 = minutes between log switches.

I suppose that forcing a checkpoint = does not forces a log switch (whereas the log switch forces the = checkpoint).

Anybody having an idea on how to force = a log switch=A0?

<BR><FONT SIZE=3D2 FACE=3D"Arial">Alain.</FONT>
</P>
<UL>
<P><A NAME=3D"_MailData"><FONT SIZE=3D1 FACE=3D"Arial">-----Message =

d'origine-----</A>
 De:     Kieran Murray [SMTP:Kieran.Murray_at_esat.com] Date:   jeudi 30 novembre 2000 10:46 =C0:      Multiple recipients of list ORACLE-L Objet:  RE: Frequency of Log Switches

Steven,

try changing the initialization = parameter LOG_CHECKPOINT_TIMEOUT to be 900 and set the = LOG_CHECKPOINT_INTERVAL to be a very high value (greater than the size of the redo = logs),
 this will cause log switches = every 15 minutes or when the log file is full.

<BR><FONT SIZE=3D2 FACE=3D"Courier New">Both of these values can =
</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">be dynamically altered using =

ALTER SYSTEM.

<P><FONT SIZE=3D2 FACE=3D"Courier New">Regards,</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">Kieran Murray</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">Norkom Technologies,</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">43 Upper Mount Street, Dublin =

2, Ireland
 Tel:- +353 86 8117916

-----Original = Message-----
 Sent: 29 November 2000 = 22:03
 To: Multiple recipients of list = ORACLE-L

I know that the recommended = optimal log switch interval is 30 minutes, and our log sizes of 20Mb average a = little less than that.  Now that I am looking to implement a standby = database, my users have a requirement that no more than 15 minutes of data = should be lost if we need to fail over to standby.  I was looking = through the Oracle 8 reference (we are running 8.0.5 on SunOS 5.6) and I could not = find one that would force a log switch based on time, not size.  Is = there one, or do I need to create a script that simply forces a log switch = every 15 minutes?

TIA, <FONT SIZE=3D2 FACE=3D"Courier =

New">-------------------------------------</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">Steven Monaghan</FONT>

Oracle DBA MSC Industrial Direct Co., Inc.<= /FONT>

<BR><FONT SIZE=3D2 FACE=3D"Courier New">Melville, NY</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">MonaghaS_at_mscdirect.com</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New"><A =

HREF=3D"http://www.mscdirect.com" =
TARGET=3D"_blank">http://www.mscdirect.com</A> <FONT SIZE=3D2 FACE=3D"Courier =

New">-------------------------------------</FONT>

This e-mail is intended for the = use of the addressee(s) only and may contain privileged, confidential, or = proprietary information that is exempt from disclosure under law.  If = you are not the intended recipient, please do not read, copy, use or disclose the = contents of this communication to others. Please notify the sender that = you have received this e-mail in error by replying to the e-mail.  = Please then delete the e-mail and destroy any

<BR><FONT SIZE=3D2 FACE=3D"Courier New">copies of it.&nbsp; Thank =
you.</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">-- </FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">Please see the official =

ORACLE-L FAQ: <A HREF=3D"http://www.orafaq.com" = TARGET=3D"_blank">http://www.orafaq.com</A>

<BR><FONT SIZE=3D2 FACE=3D"Courier New">-- </FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">Author: Steven Monaghan</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">&nbsp; INET: =

MonaghaS_at_mscdirect.com

Fat City Network = Services    -- (858) 538-5051  FAX: (858) = 538-5051
 San Diego, = California        -- Public Internet = access / Mailing Lists
 <FONT SIZE=3D2 FACE=3D"Courier =

New">-------------------------------------------------------------------=

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 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).

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New">*******************************************************************=

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TARGET=3D"_blank">http://www.marketplace.ie</A> Ireland's Home for = eBusiness
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<BR><FONT SIZE=3D2 FACE=3D"Courier New">-- </FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">Author: Kieran Murray</FONT>
<BR><FONT SIZE=3D2 FACE=3D"Courier New">&nbsp; INET: =

Kieran.Murray_at_esat.com

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