Re: RE: difference between child and parent latches?

From: K Gopalakrishnan <kaygopal_at_yahoo.com>
Date: Tue, 23 Mar 2004 04:57:34 -0800 (PST)
Message-ID: <20040323125734.2831.qmail@web41506.mail.yahoo.com>

Ryan:

My understanding is whenever/whereever,

a)single latch is not sufficiant to protect the entire data structure b)the contention for that particular latch is severe and the structure can be logically split in to multiple data structures

multiple latches are implemented and grouped as parent-child relationships.

So to answer your question, both are essentially same, but the child latches are created during instance startup (parents are defined in the code) and the number of children can be controlled by some underscore parameters.

Hope this answers your question ! if not Ask Steve Adams

Regards,
Gopal

• ryan.gaffuri_at_cox.net wrote:
  > i'm still having trouble understanding what the real difference is
  > between a parent latch and a child latch?
  > >
  > > From: K Gopalakrishnan <kaygopal_at_yahoo.com>
  > > Date: 2004/03/23 Tue AM 04:28:38 EST
  > > To: oracle-l_at_freelists.org
  > > Subject: RE: difference between child and parent latches?
  > >
  > > Paul:
  > >
  > > You will have only one latch if your shared pool is less than 250
  > MB.
  > > But the v$latch_children may (probably) have 7 entries, but only
  > one
  > > latch will be protecting the shared pool structures. This can be
  > > verified by checking the misses/sleeps for that particular child.
  > >
  > > Regards,
  > > Gopal
  > >
  

  ---

Please see the official ORACLE-L FAQ: http://www.orafaq.com

---

To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line.

--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------

Received on Tue Mar 23 2004 - 07:00:12 CST