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v$librarycache [message #201316] Fri, 03 November 2006 08:34 Go to next message
Anand Ramaswamy
Messages: 111
Registered: January 2005
Senior Member
Hi All,
I recently queried v$librarycache of a database. Below is the output:


NAMESPACE	GETHITRATIO	PINHITRATIO	RELOADS		INVALIDATIONS
SQL AREA	0.89		0.98		4,089,675.00	4,234,997.00
TABLE/PROCEDURE	0.94		0.91		43,911.00	0.00
BODY		1.00		1.00		132.00		0.00
TRIGGER		1.00		1.00		346.00		0.00
INDEX		0.88		0.82		3.00		0.00
CLUSTER		0.99		0.98		0.00		0.00
OBJECT		1.00		1.00		0.00		0.00
PIPE		1.00		1.00		0.00		0.00
JAVA SOURCE	1.00		1.00		0.00		0.00
JAVA RESOURCE	1.00		1.00		0.00		0.00
JAVA DATA	0.97		0.99		5.00		0.00


As seen the GetHitRatio & PinHitRatio of some namespace is less than 90%. Is it normal to have such a low hit ratios?
If not how can we improve them.

Thanks in advance
qA
Re: v$librarycache [message #201490 is a reply to message #201316] Sat, 04 November 2006 15:46 Go to previous messageGo to next message
kimant
Messages: 201
Registered: August 2006
Location: Denmark
Senior Member
Have You any performance problems on the database, or are You bored and just looking for switches and knobs to turn?

Are You sad that some objects are not kept in the cache at all times?

You could increase shared pool.
But if You are lowering db cache to do so, it might make performance worse.

Have You looked at using Automatic memory tuning?

Br
Kim
Re: v$librarycache [message #201498 is a reply to message #201490] Sat, 04 November 2006 23:16 Go to previous messageGo to next message
Anand Ramaswamy
Messages: 111
Registered: January 2005
Senior Member
Hi Kim,
I have not heard about Automatic Memory Tuning. Can you throw some light on that?

Regards
Re: v$librarycache [message #201537 is a reply to message #201498] Sun, 05 November 2006 13:35 Go to previous message
kimant
Messages: 201
Registered: August 2006
Location: Denmark
Senior Member
No problem:

http://www.oracle.com/technology/products/manageability/database/sga.html

Wink
Kim
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