Showing posts with label BookReview. Show all posts
Showing posts with label BookReview. Show all posts

6.29.2011

Book Review by Aman Sharma

A very positive and elaborated review by Aman Sharma for our Oracle 11g R1/R2 Real Application Clusters Essentials book.

Book Review.

A big thank you to Aman for his wonderful and very honest review.

Enjoy reading,

Jaffar

3.05.2010

Book Review: Oracle 11g Streams Implementer's Guide

I know its been more than a month I had promised to write a review on this book at my blog. The fact is that I was occupied by too many production critical  issues that doesn't allow me to concentrate on any thing. Nevertheless, I took sometime time to fulfill my promise and here is my chapter-by-chapter review:

Chapter 1: All the Pieces: The Parts of an Oracle 11g Streams Environment
I strongly believe in that the basic understanding of any architecture is the most important factor for  the successful implementation.This is one of the most vital chapter of the book where it discussed thoroughly setting about various types of streams environments, such as, single database, bi-directional, master-to-master plus it also talked about the their architecture and some internal mechanics.  Some very important key factors that are involved in the implementation phase, like, the importance of network design involved between the sites, important initialization parameters that are needed to tweak for the good performance also have been discussed in this chapter.

Conclusion: The chapter contains a thorough explanation about the streams setup and architecture.

Chapter 2: Plot Your Course: Design consideration
This chapter provides the guidelines on the details to be considered during the streams design phase. It talks about the business requirement of your data, talks about the strategies on 'Who, What, when, Where, Why and How' terms. The other important key factor involved in the implementation is about the resource requirements on the server and the additional cost involved with the implementation.
Conclusion: The chapter provides the insights needed to design and the strategies, server resources and other important factors required during the stream implementation phase.

Chapter 3 : Prepare the Rafts and Secure Your Gear: The pre-work before configuring Oracle 11g Streams
This chapter talks about the the pre configuration work that is needed  for streams implementation. Where it discussed the importance of having reliable and stable network setup, important database parameters, setting up supplemental logging on the database, required Streams Administrator user and its permissions. It also suggest to have a separate tablespace for the LogMiner to avoid using SYSTEM or SYSAUX tablespaces are being used.

Conclusion: Over all, its a nice chapter discussing the pre work that is required for the streams implementation.

Chapter 4: Single-Source Configuration
This chapter demonstrated how to setup a single-source (uni-directional) streamed environment utilizing one of the convenient methods, Enterprise Manager (DB Console) wizards. Subsequently discussed the code which run behind the screen step-by-step. It also demonstrated how to schedule the jobs.

Conclusion: The first hands-on chapter for the readers.

Chapter 5: N-Way Replication
This chapter neatly explains about building N-Way replication(between multiple sources) topic, such as, pre-planning, techniques,avoiding conflicts, setup and etc.

Conclusion: It contains some very good examples which is can be very handy.

Chapter 6: Get Fancy with Streams Advanced Configurations
As the heading states, this chapter explained some of the advanced configuration features of Streams, such as, synchronizing capture, tag, rules, heterogeneous replication (basics) and etc. I particularly liked all the examples shows on its way of explanation about the advanced features.

Conclusion: A bit lengthy chapter, but, contains very useful set of examples.

Chapter 7 : Document What You Have and How It Is Working
I must totally agree with the authors on this point (preparing documents). This chapter started with a strong question, 'concern of loosing a key member of any team?'. Correct me if I am wrong saying if there is any boring part for the technical guys is the documentation part, don't you agree with my guys? The goal of this chapter is to use some of the Oracle packages to learn how to document, set up and monitor Streams environment.

Chapter 8: Dealing with the Ever Constant Tides of Change
This chapter has discussed the techniques for identifying and troubleshooting issues with Streams when there is a change or even no changes made. There is an in-depth explanation about the approach while doing any changes to the Stream environment, whether the change directly reflects the Streams environment or may impact from the outside of the environment.

Conclusion: A good proactive chapter.

Chapter 9: Appendix and Glossary
This chapter discussed various other options, such as Streams on Oracle RAC, Oracle GolddenGate and alternative method of monitoring streams.

Overall Impression:
I strongly recommend this book to fellow Oracle DBAs who are planning to setup Streams Environment or also who already implemented the streams and wanted to monitor their environment. I thoroughly enjoyed and learned many practical implementation details and insights in this book.  Finally, I thank Shernell at Packt Publications for providing me an opportunity to read and write a review for this book.

1.27.2010

Book Review: Oracle 11g Streams Implementers Guide

Very soon I will be receiving the 'Oracle 11g Streams Implementers Guide' ebook by Packt Publishing  and will spend some time to read the book to write the review on my blog. In the meantime, if you want to learn more about this book, you can visit here.

Happy reading,

Jaffar

4.28.2009

Oracle 11g Scheduler book by Packt Publishing

Mr. Ronald Rood wrote a book on Oracle Scheduler, titled 'Mastering Oracle Scheduler in 11g Oracle Databases' and the book will be out somtime in May. 

When publishers were seeking for technical reviewrs on this book,  I have shown my interest to be part of the reviewers team.  My inital impression on this book was not satisfactory one, I ask myself, a book on Scheduler?.  Beleive me, after reviewing the book, I realized the real strngths of Oracle Scheduler and how it can be utilized flly in complex scenarios.  Now, I am really happy to be part of the reviewers team for this book and I did learn few new Oracle 11g Scheduler enhancements and planning to implement few some of the features that suits to our requirements.

The book is due this May and for more details and pre-order details, you can use the following link:

3.01.2008

Oracle Automatic Storage Management - Book Review

I have borrowed this book from my colleague to read during the week-end and at the same time, thought of writing a summary/review. When I told my idea, I knew that my family disliked this, specially during week-end.

The book started with the ‘Foreword’ page consists of ‘History of ASM’ headline which is written by Bill Bridge (an architect in Oracle over 18 yrs and the creator of ASM).

He revealed few interesting points about ASM history, like when did he get an Idea about ASM, how it can be useful with Oracle technology and the total time which took to build ASM technology.

Chapter 1 – Storage Stack Overview

This chapter starts explaining an overview about Disk drive technology, disk layouts, Disk Drive performance, different class of storage system architectures (such as SAN, NAS, DAS and SCSI) .

RAID levels also been discussed, and storage arrays concepts too.

Conclusion:

It might look interesting, but, I have skipped this chapter in order to read more about ASM concepts.


Chapter 2 – ASM Instances

This chapter starts on a note about ASM introduction, managing ASM (startup/shutdown) instances, few important ASM Instance parameters (such as instance_type, asm_diskstring & asm_diskgroups), ASM instance new background processes, V$ ASM views, ASM installation, upgrade and patching concepts.

It also talk about the significance of two ASM files, the ‘ab_.dat ‘ and the ‘hc_.dat’ that are present under $ORACLE_HOME/dbs directory.

These files are used by the RDBMS instances for env. Information and health check monitoring.

Note : Beware, these files should not be deleted.

Conclusion:

Nothing new has been offered in this chapter. This information is already available in the Oracle documents.

Chapter 3 – ASM disk

This chapter starts explaining about logical term LUN and explained about creating LUNs, LUN optimal sizes and what is the minimum disk size (4mb) and maximum (2 power 32 MB). Also, explained disks discovery(asm_disktring init parameter) and explained the meaning of disk header status (Former, Candidate, Member & Provisioned).

It also talks about the disk preparation/configuration on different OS, such as, Solaris, AIX and Windows and how to use the asmtool & asmtoolg utilities.

Conclusion:

Nothing new offered in this chapter as well.

Chapter 4 – Diskgroups and Failure Groups.

This chapter started explaining about ASM diskgroup concepts and why ASM diskgroups are differ from typical LVM (logical volume manager). Also discussed ASM diskgroups redundancy types (normal, high and external) and their practice.

In the next segment of this chapter, it talk about Creating Diskgroups, default ASM Disk Names & how to change default disk naming convention and Diskgroup Numbers. An interesting point was made, i.e., “you are not restricted to having two failure groups for normal redundancy and three for high redundancy”.

Couple of new feature of v11g ASM, ASM Preferred Read, Diskgroups Attributes and Fast Disk Resync have been discussed.

In the last segment of this chapter, it explained I/O concepts and I/O failures. The chapter finished explaining about the Space Management Views and important columns that need to consult for space management.

Conclusion:

This chapter gave some good inputs about I/O errors, 11g new features, ASM extent management , understanding of redundancy level and etc.

Chapter 5 – ASM Space Allocation and Rebalance

I particularly liked this chapter, it presented deeper insights about ASM Space allocation, operations, such as ASM AU (Allocation Units), ASM Extents distribution evenly among existing disks, how ASM Strips works, and difference between coarse and fine-grained striping types and which type of striping is good for what type of database files.

It also discussed when to change the default values of _asm_ausize (deault 1m) & _asm_stripesize (128k/1M) and how to set/change values for VLDs databases.

I also like the way author explained about ASM Rebalance operation concepts and the impact of setting various values to the ASM_POWER_LIMIT init parameters.

I really like the point “It is commonly believed that adding and dropping a disk against the same diskgroup required two separate rebalance activities. In fact, disks can be dropped and then added and a single rebalance command can be evenly distribute the I/O”. It shows how to avoid two rebalancing operations on this occasion.

A 11g new feature Fast Rebalancing which overhead of ASM-to-ASM and ASM-toRDBMS messaging also been discussed.

Conclusion:

I really enjoyed reading this chapter which gave me great insight of ASM extent mechanism, rebalancing and striping internals. It also provides few very useful scripts.

Chapter 6 – ASMLIB Concepts and Overview:

Since I have not worked much on Linux, I have quickly reviewed this chapter about ASMLIB API which is currently available on Linux OS.

This chapter explains the benefits of ASMLIB API, and the following functionality of ASMLIB:

  • Device Discovery
  • I/O processing
  • Performance and reliability

Explained ASMLIB configuring, Managing disk in ASMLIB, Upgrading ASMLIB, Migrating to ASMLIB and troubleshooting ASMLIB.


Chapter 7 – ASM Files, Alias and Templates

This chapter explains about the default ASM Filenames, creating tablespaces, ASM Alias and Templates.

Conclusion:

Nothing new offer in this chapter.

Chapter 8 – ASM Command-Line

This chapter explained about the ASMCMD (unix based) utility and its usage. It starts explaining existing means to manage and access ASM and its components.

I really liked the following 11g new features:

Bad Block Remapping in ASMCMD. Starting with 11g, when ASM redundancy is used, it is possible to recover bad sot by restoring the data from their mirror copy using the ‘remap’ command.

Note : ‘remap’ don’t fix logical errors or corruptions detected by the RDBMS.

ASMCMD Copy:

Starting with 11g, moving datafiles in and out of ASM made easy with “copy” command introduced in ASM.

Conclusion:

11g couple of new features about ASMCMD utility worth to know.


Chapter 9 – Managing Databases in ASM

This chapter started on a note on how to use ASM while creating databases and covered some good points about the internal functionality of CSS (Cluster Synchronize Services) daemon/process, how RDBMS interacts with ASM, important background process (role of RBAL, ASMB & 00nn b/g), few vital parameters that influence ASM performance (like, processes + add 16, large_pool add additional 60k and shared_pool size additional memory to store extent maps and concluded with good examples of converting ASM no non-ASM and vice-versa.

Conclusion:

Explained well about CSS internal behavior, how RDBMS communicates with ASM instance, converting instances from ASM-to-Non ASM and vice versa.


Chapter 10 – ASM Persistent Data Structures

Stars explaining about MEATADATA and where does ASM stores the metadata, and different types of metadata. ASM has two main classes of metadata, physical and virtual metadata.

Physical metadata which located at fixed locations on disk contains the following:

  • Disk Header
  • Allocation Table(AT)
  • Free Space Table (FST)
  • Partnership Status Table (PST)

Virtual Metadata stored in ASM files and contains the following:

  • File Directory
  • Disk Directory
  • Active Change Directory (ACD)
  • Continuing Operations Directory (COD)
  • Template Directory
  • Alias Directory
  • Attribute Directory
  • Staleness Directory
  • Staleness Registry


Chapter 11 – ASM Operations

This chapter is one of those chapters I liked in this book. It really explains how ASM works internally on the following condition:

  • First time when RDBMS instance tries to access an ASM file.
  • Operations on ASM Files
  • File creation
  • File open
  • File input/output (I/O)
  • File close
  • File delete

It also talk about the variable sized extents and Striping types (such as Coarse and fine-grind), Resync, Rebalancing and ASM Instance Recovery & Crash Recovery concepts.

Conclusion:

This is one of interesting chapters present in this book which offers an internal mechanism of ASM functionality on the above mentioned operations.


On APPENDIX

Appendix A: explained about ASM and Storage Array Configurations.

Appendix B : Troubleshooting – In page, it discussed about ASM startup issues, Diskgroup mounting issues, Space related Issues and a walkthrough of an ASM alert log.

Appendix C: Scripts and Tips - Automatically Starting up and Shutting down ASM instance in Non-RAC env.

Migrating Individual Non-ASM datafiles to ASM.


Overall thoughts:

This book is recommended for someone who serious wants to study about ASM technology and its in & outs.

Having a copy of this book is better than scanning 100th of Oracle documents.

This book is summarized and explained all ASM contents to a great extent.

For me, I liked 4 chapters in this books and might need another read.

Happy Reading


Jaffar