Thanks, Anjo. When session switching occurs does the new session get the same sid and serial#? And what happens with the session being "switched/replaced" - does the transaction it was performing get commited/rollbacked? I don't see XCTEND markers before those pesky WAIT #0 in the trace file. Also if session gets switched, wouldn't this terminate sql trace for the session (in my case it doesn't)?
Thanks, Boris Dali. --- Anjo Kolk <[EMAIL PROTECTED]> wrote: > > > Cursor 0 also happens in oracle due to session > switching (multiple > sessions in the same process), oracle apps uses that > but it also could > happen with certain other application servers > (haven't investigated it). > > Anjo. > > > -----Original Message----- > Boris Dali > Sent: Monday, January 05, 2004 3:59 PM > To: Multiple recipients of list ORACLE-L > > > Thanks, Cary. > > Could you elaborate what do you mean by "wait events > associated with COMMIT processing"? Why does Oracle > need this "exchange of messages" with the client > (well, with the app server really in my case of a > 3-tier deployment) to perform a commit? > > > In any event, as I described earlier in my case I > think Cursor #0 doesn't fall in neither of the two > uses you mentioned. > > Bug 2425312 is RPC related as I understand. I don't > work distributed (single DB) and app server (and > clients - thin) don't have their own SQL engine, so > all SQL processing is happening strictly on the DB > server. So this doesn't seem to apply to me. > > And I see Cursor #0 used with no commits/rollbacks > as > part of one Oracle transaction. > > > I see these WAIT #0 flying back and forth between DB > and the app server sometimes 20 times just before > stored procs are called and I can't figure out why. > Another bug? > > Thank you, > Boris Dali. > > --- Cary Millsap <[EMAIL PROTECTED]> wrote: > > Boris, > > > > Cursor #0 seems reserved for two special uses: (1) > > wait events > > associated with COMMIT processing (also, of > course, > > ROLLBACK and > > SAVEPOINT), and (2) wait events associated with > > dbcalls not instrumented > > because of bug 2425312. > > > > > > Cary Millsap > > Hotsos Enterprises, Ltd. > > http://www.hotsos.com > > > > Upcoming events: > > - Performance Diagnosis 101: 1/27 Atlanta > > - SQL Optimization 101: 2/16 Dallas > > - Hotsos Symposium 2004: March 7-10 Dallas > > - Visit www.hotsos.com for schedule details... > > > > > > -----Original Message----- > > Boris Dali > > Sent: Thursday, January 01, 2004 10:29 AM > > To: Multiple recipients of list ORACLE-L > > > > Thanks a lot for your reply, Cary. > > > > One follow-up question. What would motivate "a > chat" > > of sometimes 5, sometimes 10-20 'SQL*Net message > > to/from client' consecutive wait lines emitted to > > the > > trace file in the following manner: > > > > WAIT #0: nam='SQL*Net message to client' ela= 2 > > p1=1413697536 p2=1 p3=0 > > WAIT #0: nam='SQL*Net message from client' ela= > 678 p1=1413697536 p2=1 > > > p3=0 WAIT #0: nam='SQL*Net message to client' ela= > 1 > > p1=1413697536 p2=1 p3=0 > > WAIT #0: nam='SQL*Net message from client' ela= > 3463 > > p1=1413697536 p2=1 p3=0 > > WAIT #0: nam='SQL*Net message to client' ela= 1 > > p1=1413697536 p2=1 p3=0 > > WAIT #0: nam='SQL*Net message from client' ela= > 3322 > > p1=1413697536 p2=1 p3=0 > > .... > > > > I see this pattern of "message exchanges" before > > calling a stored code from the app server (OCI), > so > > using forward attribution it is a call to a stored > > code that it to blame correct? > > I can't of course eliminate a call to a stored > code > > but is there something that can be done to > minimize > > amount of these 'SQL*Net message...' lines? While > > the > > latency of these waits is low, these 3-5 > > milliseconds > > get accumulated slowly, but surely. > > > > Also does cursor #0 has some special meaning in > > traces? I can't seem to create a test-case where I > > get > > cursor #0 emitted for me and yet tracing real > > applications I see it all over (like in the > excerpt > > above) > > > > > > I guess I have more than one follow-up question > :-( > > > > Thanks, > > Boris Dali. > > > > --- Cary Millsap <[EMAIL PROTECTED]> wrote: > > > > >.... > > > >WAIT #31: nam='SQL*Net message to client' ela= > 1 > > > p1=1413697536 p2=1 p3=0 > > > >WAIT #31: nam='SQL*Net message from client' > ela= > > > 692 p1=1413697536 p2=1 > > > p3=0 > > > >WAIT #31: nam='SQL*Net message to client' ela= > 1 > > > p1=1413697536 p2=1 > > > p3=0 >FETCH > > > > > > #31:c=0,e=261,p=0,cr=7,cu=0,mis=0,r=4,dep=0,og=4,tim=2001475650589 > > > >WAIT #31: nam='SQL*Net message from client' > ela= > > > 2295 p1=1413697536 > > > p2=1 p3=0 > > > >.... > > > > > > Boris, "SQL*Net message..." events are > > > "between-call" events. Their > > > times are not included in the following dbcall's > > > elapsed time. But it > > > *is* appropriate to "blame" the dbcall that > > follows > > > for the time > > > consumed by the event. That is, if you can > > eliminate > > > the dbcall that > > > follows, then you can eliminate the between-call > > > event (and its elapsed > > > time). The "assignment of blame" is what > "forward attribution" is > > > about. > > > > > > > > > Cary Millsap > > > Hotsos Enterprises, Ltd. > > > http://www.hotsos.com > > > > > > Upcoming events: > > > - Performance Diagnosis 101: 1/27 Atlanta > > > - SQL Optimization 101: 2/16 Dallas > > > - Hotsos Symposium 2004: March 7-10 Dallas > > > - Visit www.hotsos.com for schedule details... > > > > > > > > > -----Original Message----- > > > Boris Dali > > > Sent: Monday, December 29, 2003 9:39 AM > > > To: Multiple recipients of list ORACLE-L > > > > > > I don't have the book with me right now, but I > am > > > obviously missing something in the "forward > > > attribution" concept as it doesn't seem to help > me > > > in > > > explanation of the following lines: > > > > > > .... > === message truncated === ______________________________________________________________________ Post your free ad now! http://personals.yahoo.ca -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Boris Dali 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). 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