Going by the original poster's use of the word "suffering", there were at least 2 <unprintable> bugs in 8i prior to 8.1.7.4, if the versions are relevant in this case.
----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Wednesday, December 03, 2003 9:39 PM > > My current understanding is: > a) For normal buffer gets, > the latch is acquired, > the chain is scanned > the buffer is pinned > the latch is released > the buffer is used > -- > the latch is acquired > the pin is dropped > (although the pin may be held > for the duration of the SQL or pl/sql > call if Oracle expects to revisit the buffer) > > b) Consistent gets - examination > the latch is acquired > the chain is scanned > if the buffer can be found it read > the latch is dropped > > Iin case (b), Oracle can make use of a > shared read latch - where the underlying > CPU supports it. > > But I may be wrong - especially about (b), > and I haven't identified all the cases where > an examination is legal. > > > Question 2 - the best answers come from Steve Adams. > But in summary, think library cache latch children - you > may need to validate several objects in the library cache > at once, and they could be covered by different child latches. > > Latches have a level#, from 0 to 9, and there is a precedence > of latch acquisition across levels that is designed to stop latch > acquisition deadlocks (again see S.A.). > > The holding of multiple latches also explains the presence of > the column named (something like) waits_holding in v$latch. > You have waited for this latch whilst holding another latch. > > > Regards > > Jonathan Lewis > http://www.jlcomp.demon.co.uk > > The educated person is not the person > who can answer the questions, but the > person who can question the answers -- T. Schick Jr > > > One-day tutorials: > http://www.jlcomp.demon.co.uk/tutorial.html > > > Three-day seminar: > see http://www.jlcomp.demon.co.uk/seminar.html > ____UK___November > > > The Co-operative Oracle Users' FAQ > http://www.jlcomp.demon.co.uk/faq/ind_faq.html > > > ----- Original Message ----- > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> > Sent: Wednesday, December 03, 2003 4:19 AM > > > Hi All, > > My system is suffering in cache buffer chain,I found the reason. > My general questions is > 1) > When the process holding the latch how long the latch will be held ,until > the hase chain is read or > the process goes to the particular block and return the rows(output) ? > > 2) > When the situation will occur for the process to hold two latches(different > or same) simultaneously ? > > Please reply. > > Syed. > > > > > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Jonathan Lewis > 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: Binley Lim 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).
