Home » RDBMS Server » Performance Tuning » Setting flash cache initialisation parameters (11g/r2 (OEL 5.5 running patch 9654983))
Setting flash cache initialisation parameters [message #470980] Wed, 11 August 2010 13:39 Go to next message
dsub42
Messages: 72
Registered: April 2010
Location: uk
Member
Hi could someone please help me to set up flash cache.,..

I have OEl 5.5 installed and patched.

I have my SSD mounted..

but when i ran the command 'alter system set db_flash_cache_file ='/media/ssd/' scope=spfile;'

.... I totally messed up my database, and It wouldn't startup giving ORA-01078: failure in processing system parameters...

I have now fixed this and am back to square one ...

Could someone plzzzz help me set up the initialisation params?
Re: Setting flash cache initialisation parameters [message #470981 is a reply to message #470980] Wed, 11 August 2010 13:48 Go to previous messageGo to next message
Michel Cadot
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Registered: March 2007
Location: Nanterre, France, http://...
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What does "plzzzz" mean? I couldn't find it in my dictionary.

Regards
Michel
Re: Setting flash cache initialisation parameters [message #470982 is a reply to message #470981] Wed, 11 August 2010 13:48 Go to previous messageGo to next message
dsub42
Messages: 72
Registered: April 2010
Location: uk
Member
really? wow thanks - really helpful!

So can anyone with actual experience of flash cache help?

Thanks

[Updated on: Wed, 11 August 2010 13:50]

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icon6.gif  Re: Setting flash cache initialisation parameters [message #470984 is a reply to message #470980] Wed, 11 August 2010 15:06 Go to previous messageGo to next message
LKBrwn_DBA
Messages: 487
Registered: July 2003
Location: WPB, FL
Senior Member

Did you also specify the "required" DB_FLASH_CACHE_SIZE initialization parameter?



[Updated on: Thu, 12 August 2010 09:08] by Moderator

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Re: Setting flash cache initialisation parameters [message #471051 is a reply to message #470984] Thu, 12 August 2010 01:52 Go to previous messageGo to next message
John Watson
Messages: 8935
Registered: January 2010
Location: Global Village
Senior Member
You need to specify a filename, not a directory (at least, I do on my simulation).
But "totally messed up" is not an Oracle error message, what was in the alert log for the failed startup?
Re: Setting flash cache initialisation parameters [message #471263 is a reply to message #471051] Fri, 13 August 2010 01:49 Go to previous messageGo to next message
John Watson
Messages: 8935
Registered: January 2010
Location: Global Village
Senior Member
Hi - did you get any further? What was the problem? Not many people have the opportunity to work with a flash cache, I for one would be interested to know your results. What performance did you get when comparing it to disc i/o? For instance,

select name,value from v$sysstat where name in ('physical read flash cache hits','flash cache inserts','physical reads','session logical reads');
select event,total_waits_fg,time_waited_micro_fg,time_waited_micro_fg / total_waits_fg from v$system_event where event in ('db flash cache write','db flash cache single block physical read','db flash cache multiblock physical read','db file sequential read','db file scattered read');

[Updated on: Fri, 13 August 2010 01:59] by Moderator

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Re: Setting flash cache initialisation parameters [message #513488 is a reply to message #470980] Mon, 27 June 2011 16:05 Go to previous message
Gollum
Messages: 2
Registered: June 2011
Junior Member
Hey, did you ever get his resolved?
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