performance tuning via outlines

7/25/2019 Performance Tuning via Outlines

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Oracle Performance Tuning Outline Method

Adarsh Vaish

July 9, 2009


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Background

Achievement

Introduction to Outlines

Creating & sing Outlines

!e"loyment & #aintenance Activities

$ros and Cons

%eerences

' & A

Agenda


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Background

Bet)een June to Octo*er 200+ timerame, !aily Billing$erormance )as *ecoming an Issue it )ould run intoBusiness hours regularly-

%oot Cause Analysis determined degradation o Auto.Invoice$erormance as the num*er one cause-

Auto.Invoice )ithin Oce/s Oracle %$ system is a 1tandard"rocess and there have *een no customiations-

!ue to Oracle de.su""ort risk and lack o source code, need

)as to come u" )ith an innovative method o $erormancetuning )ithout any code changes or a""lication o "atches-

Oracle 31tored Outlines4 aka 3$lan 1ta*ility4 method )as usedor tuning Auto.Invoice "erormance )ithout any code changes-


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Achievement

Auto.Invoice $erormance and Overall 1ystem Band)idth gainsachieved are illustrated *elo)6

Go-Live


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Introduction to Outlines

Oracle o"timier tries to choose *est e8ecution "ath to retrieve oru"date data ints can *e used to orce Oracle to use a s"eciic ordesired e8ecution "ath-

1tarting rom Oracle +-:, it is no longer re;uired to re)rite the1'< to add hints, they can *e "rovided )ithout touching the code-

=his eature is kno)n as 1tored Outlines, or $lan 1ta*ility, and theconce"t is sim"le6 1tore inormation in the data*ase that says6 3iyou see an 1'< statement that looks like >>> then insert thesehints in the ollo)ing "laces4-

I Outline is ena*led or the statement, Oracle automaticallyconsiders the stored hints and tries to generate an e8ecution "lanin accordance )ith those hints-

A stored outline consists o t)o com"onents . an 1'< statementthat you )ish to control, and a list o hints that Oracle should a""lyto that 1'< statement- Both com"onents are stored in the

data*ase in a schema called outln-


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Creating !sing Outlines

Outlines can *e created automatically *y Oracle or manually ors"eciic statements-

=he automatic creation o outlines is controlled using the3create@stored@outlines4 "arameter that can *e set at session orinstance level using the ollo)ing commands6

Once this "arameter is set at session or instance level outlines are"roduced or all statements e8ecuted *y the session or instanceres"ectively-

..1)itch O automatic creation o stored outlines-A


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Outlines can *e generated or s"eciic statements using theC%A= O=


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Outlines are stored in the O


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ou can test i an outline is *eing used )ith the VG1'< vie)-'uery the O=


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!e"loyment & #aintenance Activities

=his tuning method involves identiying an o"timal 8ecution"lan )hich is not getting used . A""lications team corede"loyment activities are "erormed *y the !BA team-

!BA Activities the Dirst =ime a e) Outline is Created

Create a stored outline or original statement LOutline :M Create stored outline or hinted statement LOutline 2M

31)a"4 the hints *et)een Outline : and Outline 2

In a nutshell, get the outline or our original statement and makeit use the ne) e8ecution "lan as i it )as hinted *y s)a""ing

the 2 Outlines-

!BA #aintenance Activities

A !ata*ase =rigger is created u"on 1tartu" to automaticallyena*le Outlines ater any maintenance do)ntime-


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Pros and Cons

$ros normous *eneits in terms o $erormance tuning i sourcecode is not availa*le or cannot *e tuned via ;uery re)rite-

As there is no code change involved ollo)ing additional*eneits are achieved6 #itigates Oracle de.su""ort risk

!e"loyment time is greatly reduced Can *e used )hen u"grading rom %ule Based to 'uery

O"timier or during ne) Oracle data*ase release- Outlines can *e moved *et)een systems *y category using

Im"ortR8"ort, thus hel"ing migrations *et)een =est and$roduction systems-

Cons By using a stored outline, the system may *e orcing the

o"timier to choose a dierent e8ecution "lan, so thereshould *e regular monitoring o the eects o the storedoutlines over time to make sure there is no negative im"act-


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"eferences

Oracle #anuals s"eciic to !ata*ase version

#etalink article 92202-:

el"ul e* %


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#uestions$

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