The OakTable network is a network for the Oracle scientist, who believes in better ways of administering and developing Oracle based systems. The network is an informal organisation, which will get together at various Oracle events, for instance the Database Forum run by Miracle every year in Denmark, OracleWorld events and EOUG forums.
Člani omrežja OakTable že tretje leto aktivno sodelujejo na strokovnem srečanju slovenskega društva uporabnikov programske opreme Oracle. Letos so med predavatelji:
Christian Antognini, Švica
Since 1995 I have been focusing on understanding how the Oracle database engine works. My main interests range from logical and physical database design, the integration of databases with Java applications, to the cost-based optimizer and basically everything else related to performance management and tuning. I am currently working as a senior consultant and trainer at Trivadis AG (http://www.trivadis.com) in Zürich, Switzerland. If I am not helping one of my customers to get the most out of Oracle, I am somewhere lecturing on optimization or new Oracle database features for developers.
In addition to the Hotsos Symposium 2005 this year I hold about 15 courses, seminars or presentations (mainly for my company but for the Swiss and German user groups as well).
Predvanja na SIOUG 2009:
Interpreting Execution Plan
An execution plan describes the operations carried out by the SQL engine to execute an SQL statement. Every time you have to analyze a performance problem related to an SQL statement or simply question the decisions taken by the query optimizer, you must know the execution plan. Whenever you deal with an execution plan, you carry out three basic actions: you obtain it, you interpret it, and you judge its efficiency. The aim of this session is to describe in detail how you should perform the second of these three actions?in other words, how to read execution plans.
Parallel Processing
When you submit a SQL statement to a database engine, by default it is executed serially by a single server process. Therefore, even if the server running the database engine has several CPUs, your SQL statement runs on a single CPU. This means that the amount of resources used for the execution of a SQL statement is restricted by the amount of processing a single CPU can do. The purpose of parallel processing is to distribute the execution of a single SQL statement over several CPUs.
This session describes not only how parallel processing works, but also when to use it. In other words, how it can be used to improve performance. In addition, it also describes how to configure the database engine to efficiently support it.
Jože Senegačnik, Slovenija
Jože Senegačnik se je prvič srečal z Oracle bazo podatkov leta 1988, ko je bila Aktualna še verzija 4, prav takrat pa je prihajala v produkcijo nova verzija 5. V začetku svojega službovanja v IT je bil zadolžen za razvoj prostorskih informacijskih sistemov (GIS) za potrebe mesta Ljubljana. Od leta 1992 dalje je samozaposlen kot zasebni raziskovalec. Kot zunanji sodelavec firme Aster d.o.o. in kasneje S&T Slovenija je sodeloval pri izgradnji informacijskih sistemov na področju državne uprave, ki temeljijo na podatkovni bazi Oracle in se ukvarjajo s prostorskimi podatki.
Zadnjih 10 let se ukvarja predvsem z optimizacijo delovanja programske opreme in same relacijske baze Oracle. Jože je kot edini Slovenec član prestižnega svetovnega kluba Oracle gurujev OakTable. Je tudi
znan predavatelj tako na domačih strokovnih srečanjih, kot je na primer letna konferenca SIOUG, kot tudi mnogih mednarodnih srečanjih tako v Evropi kot ZDA. Predava tudi za Oracle University v okviru tako imenovanih »Celebrity« seminarjev. Jože je tudi pooblaščeni revizor informacijskih sistemov (CISA).
V prostem času je Jožetov konjiček petje in kuhanje, v zadnjih letih pa tudi letenje, ne le za zabavo ampak tudi, ko je gre za službeno pot v tujino bodisi za izvedbo predavanja ali obisk konference kjerkoli v Evropi.
Predavanja na SIOUG 2009:
Kako napisati dobro PL/SQL kodo?
Mnogokrat se zdi, da je pisanje PL/SQL kode povsem preprosto in razen poznavanja sintakse jezika skoraj ne zajhteva drugega znanja. Pa je res tako? Odgovor seveda ni povsem enostaven, še dodatno se zaplete takrat, ko napisana koda deluje prepočasi in nikakor ne ustreza zahtevam naročnika. V predavanju si bomo ogledali nekaj najbolj pogostih primerov, kako lahko z uporabo neprimernih tehnik programiranja onemogočimo učinkovito delovanje kode, ob enem pa si bomo tudi pogledali, kako lahko ugotovimo ozka grla v izvajanju PL/SQL kode.
RMAN v praksi
RMAN se je pojavil prvič v vreziji Oracle 8, od takrat dalje pa je njegova funkcionalnost vedno večja. V predavanju si bomo ogledali nekaj primerov uporabe RMAN-a, ki izkoriščajo njegovo manj znano funkcionalnost in segajo tudi na področje visoke razpoložljivosti brez nakupa dodatnih licenc. Dotaknili se bomo tudi možnosti optimizacije backupa in tudi restavracije podatkovne baze.
Randolph Geist, Nemčija, Oracle ACE
Randolf Geist has been working with Oracle software for 15 years now, since 2000 as freelance database consultant, focusing primarily on performance related issues, in particular helping people to understand and unleash the power of the Oracle cost based optimizer (CBO). He is writing on his blog about CBO related issues and also regularly contributing to the OTN forums. Randolf is an Oracle Certified Professional DBA (OCP DBA) for Oracle Version 8i, 9i and 10g. He is also maintaining SQLTools++, an open-source Oracle GUI for Windows (tm) which is available from Sourceforge.net and his homepage.
Predavanja na SIOUG 2009:
CBO fundamentals: Understanding the different modes of System Statistics
Understanding the different modes of System statistics aka. CPU costing and the effects of multiple blocksizes. One of the most important components of the Oracle database is still the optimizer, since everything the database does is SQL. This presentation explains what System Statistics mean to the cost based optimizer. It covers in-depth the different available System Statistics modes along with explanations and samples about the formulas and arithmetics used. Finally the effects of multiple non-standard block sizes are shown and why it is a bad idea in general to use them for "tuning" purposes.
Target audience are DBAs and developers who are looking for a deeper understanding how the cost-based optimizer works.
Anjo Kolk, Nizozemska, Oracle ACE Director
Anjo Kolk has been working for Oracle from 1985 to 2001 in Holland, Ireland, Japan and the USA. He is recognized as the father of the Oracle Response Time Tuning methodology (YAPP) which was first documented in the YAPP white paper in 1998 and publicly used in his website oraperf.com. He has been speaking at several Oracle conferences all over the world and nowadays he specializes in troubleshooting Performance problems in large scale Oracle based systems.
Predavanja na SIOUG 2009:
7 Levels of Application Efficiency
Tuning databases are the norm even when the applications are responsible for the problems. Obvious problems are SQL statements that need to be optimized, but scalability of an application is also limited by the implementation. This presentation will show four programs that solve the same problem with a difference in efficiency (almost by a factor of 50). It will explain how to implement scalable and efficient programs.
Why the middle tier is slowing down the database?
In Multi Tier Systems performance problems are quite often traced to the database. This presentation will have a look at these problems and show that most of these problems actually originated in the Middle Tier and that some times with very simple settings one can dramatically improve the performance.
