Dennis, You in fact put all correct references and added the response to your own question and here is my justification: When I once browsed G. Millsap/jeff Holt book I got the impression that it is more application focused than single SQL. I say 'seems' as I have the book but did not yet read it, and reckon I may be wrong, not a problem. But decision had to be taken and transformed in action plan, so I created my DUC short list considered from a production DBA point of view - Which I am - and decided to go first for the lower layers of Oracle understandings, abandonning the rest for an hypthetical futur. Production DBA have usually marginal influence on subsequent release for specific applications in their data centers, especially when they deal whith tens of applications and hundreds DB (Dev,QA,PRD,STDBY). In this respect, conceptual and design mastering of a DB is just academic knowledge but at the stage where I live - production - it is too late. B.Polarski http://www.smenu.org ----- Message d'origine ---- De : Dennis Williams <oracledba.williams@xxxxxxxxx> À : bpolarsk@xxxxxxxxx Cc : oracle-l@xxxxxxxxxxxxx Envoyé le : Mercredi, 26 Juillet 2006, 7h50mn 47s Objet : Re: Query tuning exercise: what to look for in a 10053 trace Bernard, Over the years I've come to appreciate someone who can summarize a complex topic in a few succinct statements. Just to clarify for the rest of us, please confirm that you are referring to: - Oracle Wait Interface: A practical Guide to Performance Diagnostics and Tuning (Osborne Oracle Press Series) by Richmond Shee, Kirtikumar Deshpande, and K. Gopalakrishnan - Cost-Based Oracle Fundamentals by Jonathan Lewis (I didn't know this was out). - SQL Tuning by Dan Tow My only quibble is that there needs to be a place in your pantheon for - Optimizing Oracle Performance by Cary Millsap and Jeff Holt. I'm not sure what that does for your letter arrangement. Of course, since the topic is SQL statement tuning, you could argue that Cary looks more broadly to the application performance, rather than focusing on a specific SQL statement. Dennis Williams On 7/26/06, Bernard Polarski <bpolarsk@xxxxxxxxx> wrote: Here we find again the holy trinity : DUC Diagnose-Understand-Cure D : Why is my DB so slow --> Oracle wait interface (Oracle press) U : Why the CBO is doing that --> Cost based optimisation (JL) C : What should I do now --> Dan Tow, SQL tuning (Oreilly)