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September 2013

Book: Expert Oracle RAC 12c

A quick note, Expert Oracle RAC book co-written by me is available now: Expert Oracle RAC 12c. I have written about 6 chapters covering the RAC internals that you may want to learn :) I even managed to discuss the network internals in deep, after all, network is one of the most important component of a RAC cluster.

Legacy data release management is a losing battle

 Don’t Miss Out!  Live webinar on DevOps workflow  with demos and Q&A

Mark your calendar for Tuesday, September 10th when we’ll be giving a live demo of the DevOps workflow with Delphix and Red Gate Schema Compare for Oracle. The presentation will be followed by a Q&A session with James Murtagh. Register here!


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VirtualBox 4.2.18 Released…

VirtualBox 4.2.18 was released a little over a day ago. Not sure how I missed that one… :)

The downloads and changelog are in the usual places. Happy upgrading!



SQL Tuning Fundamentals: Execution Plans - September 17 Webinar

Register now and join me for my next webinar entitled "SQL Tuning Fundamentals: Execution Plans".

Hash Joins

I’ve written notes about the different joins in the past – but such things are always worth revisiting, so here’s an accumulated bundle of comments about hash joins.

Finding Oracle Home

business vision

Oracle IO on linux: database writer IO and wait events

This post is about database writer (dbwr, mostly seen as dbw0 nowadays) IO.
The testenvironment in which I made the measurements in this post: Linux X64 OL6u3, Oracle (no BP), Clusterware, ASM, all database files in ASM. The test environment is a (VMWare Fusion) VM, with 2 CPU’s.

It might be a good idea to read my previous blog about logwriter IO.

The number of database writers is depended on the number of CPU’s visible to the instance (when not explicitly set with the DB_WRITER_PROCESSES parameter), and seems mostly to be CEIL(CPU_COUNT/8). There might be other things which could influence the number (NUMA comes to mind). In my case, I’ve got 2 CPU’s visible, which means I got one database writer (dbw0).

DecOps Conundrum: Managing DB dependent development

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Business is caught in a conundrum of tightening budgets which means less systems and resources for developers which means fewer, slower, buggier applications for the business. The business depends on the applications and access to data.

How do you manage development when development depends on underlying databases? Database have no data control like source control for  code. For code it’s easy to have a trunk  with branches, merges with tools like SVN and GIT but when the  code depends on the underlying database state how do you manage it?

EM12c Enterprise Monitoring, Part IV

This is Part IV in a multi-part series, demonstrating how to take EM12c from out of the box to enterprise level.