Arup, Just picking up the thread on the BBWs. (Btw, I asked this question in this list - never got an answer!) The following undocumented parameter limits the numbe of CR copies in the Block buffers.
Name Value --------------------------------------------- ------------------------------ Description ---------------------------------------------------------------------------- --- _db_block_max_cr_dba 6 Maximum Allowed Number of CR buffers per dba What if there are more than 6 concurrent update requests for the same block. Would that not result in BBW? John Kanagaraj Oracle Applications DBA DBSoft Inc (W): 408-970-7002 Disappointment is inevitable, but Discouragement is optional! ** The opinions and statements above are entirely my own and not those of my employer or clients ** > -----Original Message----- > From: Arup Nanda [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, February 19, 2003 8:24 AM > To: Multiple recipients of list ORACLE-L > Subject: Re: Automatic Segment Space Management > > > Jay, > > I have been using ASSM for last five months in our Datawarehouse > environment. Haven't had a chance to play with the OLTP side, yet. > > Inserts are way faster as compared to system managed extent > allocation. I > read Don's article on DBAZINE. However, I would like to add > one caveat here: > ASSM does not *eliminate* buffer busy waits as the article claims; it > *reduces* them. BBW occur due to concurrent access to a > buffer by more than > one session. This will be the case regardless of number of > freelists. While > ASSM eliminates the freelist contention - thereby reducing > BBW in inserts - > it does not reduce the likelihood that more than one sessions > will try to > get the same block to the buffer cache simulataneously. > > Table drops appear a little slower in ASSM; but that could be > wrong - I > never timed dropping a table in the system managed mode. > > HTH. > > Arup Nanda > > > ----- Original Message ----- > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> > Sent: Wednesday, February 19, 2003 9:33 AM > > > > I'm continuing to introduce myself to 9i. I've been reading about > Automatic Segment Space Management, and I just wondered if > anybody had any > positive/negative experiences with it. I got some good info at: > > > > http://www.dbazine.com/burleson11.html > > > > > > Thank you, > > > > > > Jay Hostetter > > Oracle DBA > > D. & E. Communications > > Ephrata, PA USA > > > > > > > > **DISCLAIMER > > This e-mail message and any files transmitted with it are > intended for the > use of the individual or entity to which they are addressed > and may contain > information that is privileged, proprietary and confidential. > If you are not > the intended recipient, you may not use, copy or disclose to > anyone the > message or any information contained in the message. If you > have received > this communication in error, please notify the sender and > delete this e-mail > message. The contents do not represent the opinion of D&E > except to the > extent that it relates to their official business. > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > -- > > Author: Jay Hostetter > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web > hosting services > > > --------------------------------------------------------------------- > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > > the message BODY, include a line containing: UNSUB ORACLE-L > > (or the name of mailing list you want to be removed from). You may > > also send the HELP command for other information (like subscribing). > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Arup Nanda > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: John Kanagaraj INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
