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how to find out where oracle is using paging and swapping (merged) [message #127183] Sat, 09 July 2005 10:38 Go to next message
ravivkumar
Messages: 34
Registered: April 2005
Location: chennai
Member

hi
currently we have db buffer cache of 230mb,
now i am going to increase it to 350mb, oracle uses around 600mb, total RAM is 2 gb,
now i want to know wheather oracle is going for paging or swapping and how to findout that ...

Ravi
Re: how to findout whether oracle is using paging and swaping [message #127275 is a reply to message #127183] Mon, 11 July 2005 00:45 Go to previous messageGo to next message
deepa_balu
Messages: 73
Registered: March 2005
Member

To analyze paging and swapping, use the following commands. Commands used in Berkeley UNIX based systems will be marked as BSD. Commands used in ATT system V will be marked as ATT.


1. vmstat 5 5 (BSD)

procs memory page disk faults cpu

r b w avm fre re at pi po fr de sr d0 s1 d2 s3 in sy cs us sy id

0 0 0 0 1088 0 2 2 0 1 0 0 0 0 0 0 26 72 24 0 1 98


Note: There are NO pageouts (po) occurring on this system. There are also 1088 * 4k pages of free RAM available (4 Meg). It is OK and normal to have page out (po) activity. You should get worried when the number of page ins (pi) starts rising. This indicates that you system is starting to page.


2. pstat -s (BSD)

12112k allocated + 3252k reserved = 15364k used, 37280k available


Note: pstat will also give you the amount of RAM and SWAP currently available on your machine.


3. sar -wpg 5 5 (ATT)

09:54:29 swpin/s pswin/s swpot/s pswot/s pswch/s

atch/s pgin/s ppgin/s pflt/s vflt/s slock/s

pgout/s ppgout/s pgfree/s pgscan/s %s5ipf


09:54:34 0.00 0.0 0.00 0.0 12

0.00 0.22 0.22 0.65 3.90 0.87

0.00 0.00 0.00 0.00 0.00


Note: There is absolutely no swapping or paging going on. (swpin,swpot,ppgin,ppgout).


4. sar -r 5 5 (ATT)

10:10:22 freemem freeswp

10:10:27 790 5862


This will give you a good indication of how much free swap and RAM you have on your machine. There are 790 pages of memory available and 5862 disk blocks of SWAP available
how to findout whether oracle is using paging and swaping in window 2000 server [message #127300 is a reply to message #127183] Mon, 11 July 2005 02:46 Go to previous messageGo to next message
ravivkumar
Messages: 34
Registered: April 2005
Location: chennai
Member

hi
currently we have db buffer cache of 230mb,
now i am going to increase it to 350mb, oracle uses around 600mb, total RAM is 2 gb,
now i want to know wheather oracle is going for paging or swapping and how to findout that ...

os is windows 2000 server .

and how to set separate keep ,default , recycle buffers for each object .


Ravi
Re: how to findout whether oracle is using paging and swaping in window 2000 server [message #127309 is a reply to message #127300] Mon, 11 July 2005 03:35 Go to previous messageGo to next message
girish.rohini
Messages: 744
Registered: April 2005
Location: Delhi (India)
Senior Member
HI

You can define the different pools in pfile itself for the database using parameters:
DB_CACHE_SIZE: for default buffer pool
DB_KEEP_CACHE_SIZE: for keep buffer pool
DB_RECYCLE_CACHE_SIZE: for recycle buffer pool

After this when u create any object, storage buffer pool has to be defined.
eg:
create index x... storage(buffer_pool keep);


As for paging/swapping issue, if I am correct, only paging is supported in windows.

Regds
Girish
Re: how to find out where oracle is using paging and swapping (merged) [message #127339 is a reply to message #127183] Mon, 11 July 2005 05:32 Go to previous messageGo to next message
Maaher
Messages: 7062
Registered: December 2001
Senior Member
Topics merged.

MHE
Re: how to find out where oracle is using paging and swapping (merged) [message #127415 is a reply to message #127183] Mon, 11 July 2005 10:20 Go to previous messageGo to next message
smartin
Messages: 1803
Registered: March 2005
Location: Jacksonville, Florida
Senior Member
Just curious, but what is the technical difference between paging and swapping? I've always thought of them as the same thing, interchangeable terms. Basically it is data that is written out of RAM onto disk when RAM isn't big enough to hold all the data that a program needs. Is there a difference?
Re: how to find out where oracle is using paging and swapping (merged) [message #127429 is a reply to message #127415] Mon, 11 July 2005 11:35 Go to previous message
srinivas4u2
Messages: 66
Registered: June 2005
Member
Hi Martin,

When swapping happens the whole program is transferred from the memory unlike paging.

-Sri
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