Earlier this week I’ve attended RMOUG Training Days 2008 and one of the sessions was of particular interest. Mogens initiated very heated discussion about performance tuning methods that are currently in use and how inappropriate they all are because they still leave some chance for guesswork. No doubts that performance optimization has involved significantly in the recent years but there is still place for a lot of improvements. Thanks Mogens — you are invaluable BAAG supporter!

Daniel Fink was one of the presenters during that session and has done an interesting follow up. You probably know that couple month ago Dan expressed controversial idea that Oracle “wait interface is nearly useless”. My interpretation is that while wait interface removed a great deal of guesswork from performance troubleshooting, there is still a lot of times when analysts tend to rely on guesswork or don’t have other ways to go forward except educational guessing.

Now back to Dan’s most recent post — How useful are diagnostic/optimization tools?. I can’t agree more about incompleteness of performance tuning tools but can they ever be complete?

If you think about our life you would probably agree that every situation is unique. I don’t remember what philosopher said that “it’s not possible to enter a river twice in the same place”. Indeed, the current never stops and the river is never the same. No difference with Oracle and IT in general — there are no two exactly the same problems. Two situations could be similar if some differences considered to be unimportant but how do you know which differences are important and which not?

Imagine that many years ago you had several cases of latch contention that was caused by excessive parsing. You create a tool that provides suggestion to look into reducing parsing every time you have latch contention. We know now — this is obviously wrong, but in your experience at that time — it’s been always excessive parsing causing library cache latch contention. Finally, another situation showed that latch contention can be caused by hot blocks — cache buffers chains latch. It becomes clear that there are some differences that were not accounted for (i.e. unknown or claimed unimportant). That’s OK. Right? We are going to improve our tool and distinguish latches. That will work until other situations come up when contention for the same latch has a new distinctive reasons. Another time, it would be platform specific issue and so on and so forth.

As soon as we encounter new situation and new important criteria — we can improve our tool but it can’t be perfect and absolutely complete. Should we give up? Of course, no. Striving for perfection is the only way we can keep up and keep pushing the limits. Thanks god there are such people as Dan and Moans that push the limits.

PS: It’s been a while here without new activity. I remind to everyone that if they have something to say here — please do (just let me know and I set up your account for posting). Thanks to Simon and Niall for their support.

Find more about  , ,

One Response to “Can a Performance Tuning Tool be Complete?”  

  1. 1 Doug Burns

    Nice post, Alex. I was going to comment here or on Dan’s blog, but it grew a bit long ;-)
    http://oracledoug.com/serendipity/index.php?/archives/1382-How-useful-are-diagnosticoptimization-tools-Another-View.html

Leave a Reply


  • pvc blowjob pictures
  • soft video of woman masturbating
  • hot nude girl japanese
  • chubby little teen pussy
  • guy creampie in one pussy
  • Teenages sweden
  • black virgin girl free
  • black sluts videos
  • ass fuck tits girl
  • Big dicks ass
  • shocking home video
  • bliss lei getting jizz out pussy
  • Ssbbw sex videos
  • butt busting dildo video free online
  • sinna sues over topless pics
  • illegal movies young
  • girl fondling her breasts pics
  • young tight black teens
  • free nude naked wives fucking pictures
  • cuckhold and wife and blacks
  • Nude boobs bouncing
  • free first time amature anal
  • free young teen pussy galleries
  • erotic forced japanese tubes
  • extreme asian
  • Video big breast
  • Sexy tanned teens
  • free dorm room sex vids
  • amateur muscle videos
  • free online sexy naked girls
  • free pics ex wife
  • naked teen fanny
  • Best incest sex
  • columbian girls galleries
  • free females giving oral sex
  • movie dying young starring julia roberts
  • drunk naked hot lesbians videos
  • mallu movie sex cene vidio
  • testing lesbian monster sex toys
  • Angel locsin sex vidio
  • purple interracial mature
  • amateur teen sex auditions video
  • group miltf sex
  • texas teens interracial
  • ebony gaping hole pussy
  • free extreme bikini pics
  • mercy fuck movies
  • free xxx sex vdeo
  • Hardcore ebony sex videos
  • black or ebony desk
  • big boobs girlfriend amateur private video
  • free daily amateur movie
  • nude sex homemade movies
  • suck boy dick
  • little young teen girl models
  • amature fucking wife videos
  • naked pool videos
  • blonde cheerleader sexd
  • cameraman gets pussy
  • free hot young
  • small butt sex
  • free japan streaming vids
  • shave my pussy then eat it
  • kira kener mmf video
  • Aylen alvarez nude pics
  • big cock anal girl gallery
  • free wife swap videos
  • blonde milf sucking black cocks
  • girl with small firm tits fuck
  • naughty wives tits
  • fucking ass small girl
  • pussy ass babe
  • naked girl is hanged video bluff
  • non nude young girls with boys
  • free asian pantyhose sex video
  • hot wet naked teen valentine girls
  • girls naked on big brother
  • reality gallery
  • naked red headed pussy videos
  • amateur oral sex video mom
  • gorgeous wife doing anal
  • left in pussy
  • swinging wife true sex stories
  • hot young naked gir s
  • running bath water on my pussy
  • teem pictures
  • pussy ripped apart erotic stories
  • anal xxx first time
  • pretty girls nude photos pictures
  • a young girl in rags
  • briana banks hardcore
  • pictures of graphic sex
  • brunet xxx
  • Sex scene tits
  • skins show naked pictures
  • chubby chicks dick
  • watch girls gone wild megavideo
  • pussy bulge moved
  • hot blonde fucks large dicks
  • Hairy pussy fuck videos
  • free pics of miranda cosgrove naked
  • boobs dome movie
  • shemale transexual ladyboy daily gallery
  • david keith martz video
  • teen age girls and sex
  • picture of beths tits
  • beaytiful girls sex video
  • Sexy cars with girls
  • gallery before and after shaved
  • plantation ebony slave girl stories
  • free webcam girls nude
  • group sex films
  • sleeping beauty movie cast
  • asian hot teen sex free video
  • bbw anal video galleries
  • nude photo of indian teen girls
  • maira carys pussy
  • sexuail amateur personal web siotes
  • free pictures black braid styles
  • young erotic fantasy pictures
  • fat girl playing with tits
  • lingerie babes pics
  • teen fuck in bar
  • outdoor amateur girls ass
  • erin anderson sex video
  • blonde lesbian busty
  • long playing interracial amateur wife homemade
  • revenge teenage girls
  • black hairy pink pussy
  • Sex scene in the office
  • ripe pussy pic
  • couples have sex at the beach
  • interracial sex fourm
  • huge sex video
  • harold moore wife julie picture
  • wife sex threesome
  • young black women girls nudists
  • bring a white girl party
  • Lesbian teen squirting
  • wife gets two cock facial
  • shemale fucks teen girl
  • beautiful black women with big tits
  • gia lashay lesbian sex videos
  • older woman teen girls
  • anal dildoe video
  • female xxx wrestling japan
  • petite queue video erotique grosse big
  • most creamiest pussy
  • fuck teen powered by vbulletin
  • white women black men sex
  • free mp shemale vids
  • women over movies
  • Girls hostel sex video
  • girl plus girl sex orgasm
  • how get wife to suck
  • sweden amateur movie
  • amateur audition shy sex xxx
  • massive cock in wet pussy
  • Movies with sex scenes in them
  • old amateur mature women
  • free mother daughter lesbian movies
  • little boobs cone nipples pictures
  • teen spandex sex
  • interracial white wife dark meat
  • wet pussy sites
  • mature home photo galleries
  • naught teen girls
  • deep young pussy
  • tiffany teen fuck
  • wife cheating threesome
  • he wants to eat my pussy
  • amy lynn baxter pussy
  • model young girl bbs
  • nasty anal videos
  • caught wife letting lick her
  • i love thai pussy thumbs
  • free live video ass
  • naughty hardcore videos
  • skinny girl with huge nipples
  • teen asian girls naked
  • amature teen slut galleries
  • young teen swingers
  • enormous tits movies
  • redneck pussy pics
  • free latino pussy
  • youngbusty hardcore tube
  • make your own bikini pictures
  • latina blowjob galleries
  • images of shaved dicks
  • women anal movies
  • Hot girl photo shoot
  • free ass pics movies
  • hottest shemale gallery
  • Natural tits girls
  • free party tube
  • sexy latina ass
  • bizare sex pics
  • white teens black cocks alice
  • very sexy and naked video
  • asian teen mpgs
  • free interracial cute
  • movies for young ren
  • teen sex cool not erotic
  • ass and pussy closeup
  • teaching her throat video
  • pinkys tits biography pics movies
  • nudist girl party
  • Nikki sanderson sex scene
  • best free handjob movies
  • Teen scary movies
  • free very young naked teens movies
  • vid pic black girls
  • filipina teen babes