Oracle’s Real Application Cluster(RAC) is database’s industry’s most innovative, popular and (obviously) complex technologies. Using RAC and with a careful planning and proper design of the application, a shop can achieve immense scalability and performance without going for a very high end hardware. This is the reason, now a days, almost every shop that runs Oracle database, is having at least one implementation of RAC for sure and the numbers are keep on growing worldwide ensuring and establishing the fact that RAC is indeed one of the best technical milestones achieved by Oracle corp and with the upcoming releases of it for the version 11g, it has become even better!

You can read more about RAC from the below links,

http://www.oracle.com/us/products/database/options/real-application-clusters/index.html

http://en.wikipedia.org/wiki/Oracle_RAC

Being innovative technology means that RAC must be a complex piece of technology as well. Well, that should hardly come as any surprise since in RAC, there are many moving pieces and even within RAC, there is a lot that keeps on going all the time which makes it a tough thing to grasp. Though Oracle documentation does a very good job in explaining its in-how but still, its always welcome to have more information. That’s why, a book over such a complex technology is always a welcome thing. Being very advanced technology, there are just a handful of books available for it and the number is even lesser for the latest version 11.2. All these facts make the book, Oracle 11gR1/R2 Real Application Clusters Essentials from my friend Syed Jaffar Hussain and Ben Prusinski, published by Packt Publications a must-buy book!

There are always two approaches to write about a technical topic, write the internal but mostly, non-usable stuff in a real world and another, write what is going to be usable in the real life, production systems. The RAC Essential books does a very good job in making a dba very well aware about the RAC technology and holds her hand to go through with different aspects of it in a step-by-step process. The language chosen is simple, the layout within the chapters for the content is clean and doesn’t confuse one when he is reading the chapter.

The chapters start with the introduction of the high availability architecture making the reader understand that why such technology like RAC is needed. There can be several types of failures which may bring the business down and using RAC some of those failures can be taken away and one can still let the business run. With that introduction, the chapter goes into the introduction of several jewels under the umbrella of the MAA(Maximum Availability Architecture) which includes RAC, Data Guard, Streams and so on.This chapter should make the reader aware and confident about the technology and also would make him understand the necessity of it as well.

The chapter 2 starts with the RAC architecture thus diving deeper into the technical aspects of the RAC technology. This chapter also discusses the necessary hardware requirements such as network and storage, something which can be a very crucial factor in the RAC installation and configuration. With a very detailed presentation of it, the chapter goes more deeper with the explanation of some crucial processes of RAC with the discussion about ASM , the new features of 11.2 RAC and so on. With that knowledge in hand, the next chapter , chapter 3 should come easy for the reader since its about the installation and configuration of RAC. Since there are differences in the configuration of 11.1 and 11.2 RAC, the authors have tried to explain both the configurations so that the difference becomes evident to the reader.

The chapter 4 is devoted to the Automatic Storage Management(ASM). Those who are not keeping track with the latest new features of ASM, or even those who don’t know about ASM before, both should get a good deal of info about its architecture, configuration and most importantly the new things introduced in it by Oracle from 11.2. A detailed description of ASMCMD is also given which in itself has become a very elaborated utility from 11.2(there are about 60+ commands in it now compared to around 14 in the previous versions) .

The next chapters, 5, 6 , 7 and 8 covers up the most important that is needed by a production DBA to manage and administer a clustered environment. There is a lot that RAC offers and some things in RAC land are completely different compared from the single instance world. These chapters are covering the information about the debugging, handling the backups within the clustered environment and also about performance tuning, things which are not different compared to single instance but when done on RAC, come up with couples of new surprises which are covered up in these chapters. If you are not familiar with RAC before, I would suggest to read these chapters couple of times so that you can sync up the concepts and understand fully what’s there.

My favorite chapters from the entire book(just for the record, I liked the entire book) are the chapters 9 and 10 which cover up the part of upgrade and also some of the real world problems which both the authors are very well aware being old veterans in the database world. There are different ways that one can use to upgrade clustered environments and its not really a piece of cake many times. Since there can be many different bells and whistles that one would find in his own environment, may be not all the instructions given in the chapters may be applicable in the exact form but still, having an idea given here is going to be very useful for DBA to understand the entire life cycle of doing it. In the same way, its not possible that one would be lucky enough to see all the errors in his own environment, the chapter’s information about some of the real world issues related to RAC would come very handy when someone would see such things in his own world.

The 2nd last chapter is devoted to describe that how one can use the RAC in the E-biz environment. Strictly speaking about me here, since I am not having any knowledge about E-Biz, I just had a glance at it. But knowing that E-biz is a very complex piece of technology, the given information to manage it over RAC, I think it should come very useful to those DBA’s who manage it in their shops.

The book concludes with the discussion of some other components of MAA like data guard, streams and explains their usage with RAC. A detailed description of these components is provided in this chapter. Besides this, there is a very handy description of some the most useful goodies for the dba’s to be used in the clustered environment are given in a separate section. I guess that would be among the most used sections of the book.

Both Syed and Ben has done a very good job in choosing the topics , making their layout in terms of content and finally, writing them out. As I said already, RAC is something which needs that one must refer to a good book to understand it and since there is a lot of change in the 11.2 RAC, this book has come just in time for all who are willing to have a book which would prove as a very valuable addition in making the old concepts refreshed and describing the new concepts in a clear and simple manner! My sincere thanks and best wishes to Syed and Ben for their efforts to bring this book to us, the oracle community. And last but certainly not the least, my sincere thanks to Packt Publication as well for getting all the hard work done to make this book come to us. Well done guys!

I work as an Oracle consultant and most of the part of my work is related to train other Oracle professionals, letting them know that how this marvelous piece of software Oracle database, works! Though, we do discuss many things in the sessions, there are still tons of things which get skipped, either unwillingly because of lack of time,  or willingly because they are better explained than I could in some other book/note. Oracle docs is a mandatory reference from me to the delegates. In addition to it, I  also refer lots of MOS notes, articles, web links and books to my delegates since there is so much that’s written out there about Oracle at these places which at times, surpass even the standard Oracle docs as well.

Books, though being a very integral part in the learning, need to be very carefully chosen. I normally mention that even though one read 10 (bad) books about Oracle database, he/she still may not learn even a single thing. It takes a lot of effort to write a good book and when such kind of book becomes a part of your library, it becomes an asset of yours. At least, this is true for me for sure since I do purchase a lot of Oracle related books and because I spend my own personal money for this purpose, I take utmost care when I am making a purchasing decision. Today, I want to share with you one such book which I would surely recommend in my next DBA session,

Packt Publishing is doing a great work by giving opportunities to many authors to share their knowledge with the rest of the Oracle community. I got an offer by Packt Publishing earlier also to review their title Middleware Management with Oracle Enterprise Manager Grid Control 10g R5 by Debu Panda! You can read that review from here . Once again, I have got an opportunity by Packt to review another new title from them, Oracle Database 11g – Underground Advice for Database Administrators by April C.Sims. April has been working as a senior DBA with Utah University and also maintains an active Oracle related blog.

The very first thing that I liked about the book is that it was really concise. I mean, there are not too many chapters,just created to increase the count. Also the distribution of the content within the chapters has also come up very nice. April starts with telling us(which is very very important) that what we should an should NOT do when we are dealing with Oracle database. There are tons of times, I have seen people making things more serious, more worse just by not stopping at the first step where they went wrong and also, by not asking for help when they really need it! In the first chapter, April brings us these key points! A must thing to tell if you ask me!

The second chapter deals the standards that are related to Oracle database. I have seen many databases made and maintained like a complete mess, where the name of the database is something like SR1 which completely fails to tell us anything meaningful about the database, the tablespace and datafile names coming up like mytbs and mydatafile1.dbf. Now surely they are yours but you don’t need to put that in the names too since someone, who would come from outside won’t be able to understand it all. The same is true for the installation which happen where a DBA would like to happen, some times in a properly maintained way and sometimes, just where ever he likes! Sure enough that Oracle would work but in the longer run, this may become a complete mess to deal with. April, in her second chapter, makes us aware about these key points and also tells us how we can deal with them in a better by making us remind that there is an OFA standard given to the Oracle community long time back, which can help in such of kind of things. Also, she tells us about some tools and some references which would help help us whenever we would get struck anywhere.

Chapter 3 is my favorite chapter since I am completely addicted to know how things work within Oracle database internally. In this chapter, April takes us to some not-so-well-explained domains of Oracle like Oracle block dumps and how to read and use them, explains us the working of the internal parts of Oracle database architecture. In addition to these, she also explains to some new goodies offered by 11g like Automatic Memory Management! Overall, its a very interesting chapter and has become my personal favorite as well!

The next chapter deals with something which is now becoming a hot topic everywhere, Maximum Availability! In this chapter, April explains quite well how MAA architecture works and also its related components like ASM, Flashback , Flashback Logs etc. April also explains to us how we can use Grid Control for the same task. This chapter is the starting point for the next two chapters which deal with the technical stuff related to MAA in a more deeper manner.

Subsequent  chapters 5 and 6, as I said just now, go deeper into the MAA and in these, April shares with us some of the key components of it like Dataguard and Flashback which help a lot to achieve the minimum downtime approach requested by many shops. April covers up almost all what is needed to become highly available. A good description of complex technologies like Dataguard and also, how to do recoveries using both manual and 11g specific automated ways, give a very valuable information. April also explains quite extensively a very important and good tool, RMAN and its various uses, including the details of how to use it to make standby database in a very effective manner.

Since 11g is now the most latest release of Oracle database, there are and would be lots of migrations that would be happening from the pervious versions to 11g. The chapter 7 deals with the same topic and in it, April explains to us various ways to achieve a flawless migration to 11g with different approaches. Using this chapter as a reference and also the database upgrade guide, I believe , one would know everything that he needs to do a successful up gradation to 11g.

The last chapter, is a collection of information of various useful tools that can come very handy when it comes to performance tuning. Staring from ORION, ADDM, ASH , April explains to us Statspack, AWR and also the performance pages of the Enterprise Manager which are very helpful in order to both diagnose and troubleshoot performance related issues. April, in this chapter, not only talks about database related tuning tool but also touches the query tuning as well, explaining various things related to it like SPM , how statistics and optimizer works! Overall, the chapter comes up as a good reference for the performance tuning related material.

In addition to the material written by April based on her insights and experiences with Oracle database, she has also put up in almost every topic, a very extensive listing of Oracle’s My Oracle Support(MOS) document note ids. Its always very difficult to find the right document, especially when you need it the most, so this listing is very useful IMO! Those who are familiar with MOS, must agree to this that its not an easy task to find the right note for the right topic so kudos to April for doing efforts and collecting these documents id’s for us.

As I said before too, a good book is always going to remain useful and this book from April, is one of those few good ones! The book content is rich and also the language chosen is simple, making it a very good read even when it deals with such a complex technology like Oracle database. A good work done by April and a recommended book!

The review, can’t be called complete without me saying thanks to Packt Publishing for two things. One, for giving me an opportunity to get my hands on this book and review it and second, for getting this book out for Oracle community! As much effort it takes to write a good piece of literature, the same goes for getting it furnished and bringing it out for the public and Packt is going a great work in it! Hope we shall see more good Oracle related titles coming from Packt in the future as well!