How would pinning a table impact tables that may have a frequent update?

For eg lets say in a case where your customer information that is created and 
updated frequently on a daily basis, is stored in the People form, and is 
accessed when creating and updating incident records for them?

My understanding when you pin objects to memory, the read is not a frequent 
read. I do not know at what intervals the memory is updated or if it is updated 
as soon as there is a change on that object. Anybody with knowledge of that?

If the read is as frequent as an update or an insert, what impact would that 
have on pinning it to the database?

Joe

From: patrick zandi 
Sent: Thursday, September 08, 2011 2:44 PM
Newsgroups: public.remedy.arsystem.general
To: arslist@ARSLIST.ORG 
Subject: Re: Performance question CTM:People timing

** I have done this in the past:: pin "user" (T30 for me) table, this will drop 
IO to database.. have see this alot.. 



On Thu, Sep 8, 2011 at 2:36 PM, Guillaume Rheault <guilla...@dcshq.com> wrote:

  ** 
  Hi Joe, 

  I got to disagree with you again... but I guess this is what makes this ARS 
list fun!

  Pinning a table into memory is not an overkill, it is quite simple to do, you 
can ask your Oracle DBA. Since the cost of physical memory is lower and lower 
every year, it is actually more cost-effective to add some more memory to your 
database server and pin look-up tables, than optimizing the searches to these 
look-up tables; optimizing the searches will involves one or more of the 
following:

  - Possible DBA time to analyze the performance of queries
  - Remedy Admin/Developer/Consultant time to figure where those sub-optimal 
searches are being issued from, and modify them
  - Possible customizations to the ITSM application (which is what everybody is 
trying to avoid)

  Pinning a table into memory involves:

  - Small amount of DBA time to alter the T table to pin it.
  - Small amount of sys admin to add memory in the database server (this cost 
is a one time cost)

  See, when you pin the table in memory, it does NOT matter if your queries are 
crappy or inefficient, since the table data is in memory; that's the beauty of 
it!

  While you are at it, you may as well pin the T table related to the User form.

  cheers, Guillaume




------------------------------------------------------------------------------

  From: Action Request System discussion list(ARSList) [arslist@ARSLIST.ORG] on 
behalf of Joe Martin D'Souza [jdso...@shyle.net]

  Sent: Thursday, September 08, 2011 12:33 PM 

  To: arslist@ARSLIST.ORG
  Subject: Re: Performance question CTM:People timing



  ** 

  Yes I agree you would want to avoid pinning a table to memory whose contents 
are changed continuously by way of modifications or additions.. This would 
result in frequent memory writes which would beat the purpose of why you choose 
to pin it to memory in the first place.

  While the CTM:People table is a good candidate as its contents change less 
frequently in most standard environments, unless it’s a B2C environment where 
you maintain your customer base in your CTM:People form, if the table size is 
as small as 140K, just optimizing searches on it is more than enough, and 
pinning it to memory is an overkill.. Optimizing searches on this table when 
records are about that much or even upto half a million, would return the 
search in less than a fraction of a second anyways..

  Joe


  From: Guillaume Rheault 
  Sent: Thursday, September 08, 2011 12:15 PM
  Newsgroups: public.remedy.arsystem.general
  To: arslist@ARSLIST.ORG 
  Subject: Re: Performance question CTM:People timing

  ** 
  Joe,

  well, I disagree with your rationale... actually because it is not a large 
table, you can pin in it memory.
  Generally speaking, you only pin into memory look-up tables that are used 
heavily, and the people form/table is a good candidate.
  You definitely do not want to pin a transactional table (like the incident 
form).

  Guillaume




------------------------------------------------------------------------------

  From: Action Request System discussion list(ARSList) [arslist@ARSLIST.ORG] on 
behalf of Joe Martin D'Souza [jdso...@shyle.net]
  Sent: Thursday, September 01, 2011 2:19 PM
  To: arslist@ARSLIST.ORG
  Subject: Re: Performance question CTM:People timing


  ** 

  For only 140K records I don’t think you need to do anything out of the 
ordinary to boost up performance. If your statistics were not updated, it does 
make sense as Oracle didn’t know it had to use indexes and was perhaps 
attempting table scans assuming the table has no records if the statistics 
information it had for row count was 0 or thereabouts prior to updating it..

  Personally I don’t really think you can consider CTM:People with around 140 K 
records to be a large object. Its big but not that big enough to be considered 
to pin to memory..

  Joe

  From: John Sundberg 
  Sent: Thursday, September 01, 2011 1:31 PM
  Newsgroups: public.remedy.arsystem.general
  To: arslist@ARSLIST.ORG 
  Subject: Re: Performance question CTM:People timing

  ** True... good suggestion. 




  Fundamentally - I was looking for what is "normal" -- what we were seeing was 
what we thought was slow. But - just cause you think something is slow - does 
not mean that it is slow. Sometimes -- you have to look to your neighbors and 
compare. 


  So - thanks to all that shared their timings and system info.





  -John



  On Sep 1, 2011, at 8:30 AM, Guillaume Rheault wrote:

  ** 
  One more way to make things even faster in Oracle is to "pin" the underlying 
T table into memory.
  Ask the DBA over there to do that

  -Guilalume




------------------------------------------------------------------------------

  From: Action Request System discussion list(ARSList) [arslist@ARSLIST.ORG] on 
behalf of John Sundberg [john.sundb...@kineticdata.com]
  Sent: Thursday, August 25, 2011 7:25 AM
  To: arslist@ARSLIST.ORG
  Subject: Re: Performance question CTM:People timing


  ARSlist: "Where the Answers Are"_ 
  _attend WWRUG11 www.wwrug.com ARSlist: "Where the Answers Are"_ 



-- 
Patrick Zandi
_attend WWRUG11 www.wwrug.com ARSlist: "Where the Answers Are"_

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