As far as I know, the jury is still out - I haven't had a chance yet to see if (a) the problems Dan found in 9.0.1.1 are fixed and (2) I like the way it works. Also, it does require 9i and I'm not yet ready to go there with everything. Even with 9i and system managed undo, rule #4 will still be in effect!
Don Granaman [certifiable OraSaurus] ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Saturday, June 29, 2002 9:38 PM Don, 9i has system managed undo -- you don't think it works yet? Rachel --- Don Granaman <[EMAIL PROTECTED]> wrote: > I prefer to have OPTIMAL set and deal with "long running large > transactions" > another way - setting "OPTIMAL" on the developers! Granted, this > doesn't > work for 3rd party products, but I usually deal with in-house > applications. > Getting this to work requires: (1) having enough rollback segments, > (2) > large enough rollback segments that extends almost never occur, and > (3) NOT > having the "one giant rollback segment for large jobs", and, most > importantly, (4) all "batch-lookin' thingies" have to be reviewed by > the DBA > and optimized, by either the DBA or the developer - or both, until > they pass > muster. Using this, I rarely seen an ORA-01555 or a rollback shrink > (over > six months on the systems I'm working with now) - and when I do, I > know that > it (usually) means that somebody broke rule #(4). When that happens, > I > track it down and work with the developer to fix it. My experience > is that > the vast majority of developers are receptive - they actually like to > have > their code run without problems. > > Of course, this assumes that the "wasted" disk space for (1) and (2) > is not > a significant issue. It rarely is, but I work almost exclusively > with > (essentially) OLTP systems where space is typically less critical > than I/O > throughput capability and reliability. Usually, we have to add disks > for > performance rather than space. The database datafile drives are > typically > 36 GB (less often 18 GB) and are rarely "full", so a GB or two more > for > rollback tablespace is OK. If I had to operate under the space > constraints > that many seem to have, I might not set OPTIMAL either. > > I am looking forward to the day that this "no OPTIMAL" suggestion > fades into > the "myths and folklore" category. Either because of basic policy > changes > (e.g. the extents myth), a better Oracle algorithm (e.g. 10i system > managed > undo???), more intelligently designed batch processes in > applications, or > the trend towards ever-increasing drive size. > > Note: All this doesn't mean that I don't understand why so many use > the > "manual shrink" method. My philosophy differs in that not setting > OPTIMAL > should be a last resort, not a blanket policy. > > Don Granaman > [OraSaurus] > > ----- Original Message ----- > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> > Sent: Thursday, June 27, 2002 10:13 AM > > > One of the constant comments regarding rollback segments is not to > set > optimal. I am wondering why this setting is often discouraged. I have > my own > ideas, but I want to gather more opinions and experiences. > > Daniel W. Fink > Sr. Oracle DBA > MICROMEDEX > 303.486.6456 > > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Don Granaman > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 > San Diego, California -- Public Internet access / Mailing > Lists > -------------------------------------------------------------------- > 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). __________________________________________________ Do You Yahoo!? Yahoo! - Official partner of 2002 FIFA World Cup http://fifaworldcup.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rachel Carmichael INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- 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.com -- Author: Don Granaman INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- 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).
