db.person.find( { "role" : "DBA" } )

Wow! it has been a while since I posted something on my blog post. I have been very busy, moving to MongoDB, learning, learning, learning…finally I can breath a little and answer some questions. Last week I have been helping my colleague Norberto to deliver a MongoDB Essentials Training in Paris. This was a very nice experience, and I am impatient to deliver it on my own. I was happy to see that

I think you should submit an abstract

This is not your typical posting from me. But I just received a LinkedIn message and it got me motivated  enough to write this.

A colleague, who has been working with Oracle for over 15 years, sent me a message about the pearls of working for a consulting company that has kept him on the road for about a year now. He's had enough and is looking for something else that will keep him close (more...)

The Danger of Moving Incrementally Updated Datafile Copies

When I sat down at my desk yesterday morning I was greeted with some disturbing email alerts notifying me that one of the NFS mounts on my standby database host was full. This was the NFS mount that held an image copy of my database that is updated daily from an incremental backup. The concept and an example can be found in the documentation. With a 25Tb database, waiting to restore from backups is not (more...)

Learn a bit Oracle Scheduler with BROKEN state

On Oracle Database, DBAs can check broken job for Oracle Job (dbms_job) at *_JOBS.BROKEN column. Anyway, DBAs have changed from DBMS_JOB to DBMS_SCHEDULER. So, I was curious How to check broken job for Oracle Scheduler (DBMS_SCHEDULER)? After found out... DBAs can check on *_SCHEDULER_JOBS.STATE column.

STATEVARCHAR2(15)Current state of the job:

When does Oracle Scheduler change STATE to be BROKEN?
Then, (more...)

The Twelve Days of NoSQL: Day Twelve: Concluding Remarks

On the twelfth day of Christmas, my true love gave to me Twelve drummers drumming. The relational camp put productivity, ease-of-use, and logical elegance front and center. However, the mistakes and misconceptions of the relational camp prevent mainstream database management systems from achieving the performance level required by modern applications. For example, Dr. Codd forbade […]

The Twelve Days of NoSQL: Day Eleven: Mistakes of the relational camp

On the eleventh day of Christmas, my true love gave to me Eleven pipers piping. Over a lifespan of four and a half decades, the relational camp made a series of strategic mistakes that made NoSQL and Big Data possible. The mistakes started very early. The biggest mistake is enshrined in the first sentence of […]

The Twelve Days of NoSQL: Day Ten: Big Data

On the tenth day of Christmas, my true love gave to me Ten lords a-leaping. The topic of Big Data is often encountered when talking about NoSQL so let’s give it a nod. In 1998, Sergey Brin and Larry Page invented an algorithm for ranking web pages (The Anatomy of a Large-Scale Hypertextual Web Search […]

The Twelve Days of NoSQL: Day Nine: NoSQL Taxonomy

On the ninth day of Christmas, my true love gave to me Nine ladies dancing. NoSQL databases can be classified into the following categories: Key-value stores: The archetype is Amazon Dynamo of which DynamoDB is the commercial successor. Key-value stores basically allow applications to “put” and “get” values but each (more...)

The Twelve Days of NoSQL: Day Eight: Oracle NoSQL

On the eighth day of Christmas, my true love gave to me Eight maids a-milking. Soon after publishing a scathing indictment of NoSQL in May 2011, Oracle abruptly reversed course and released its own NoSQL offering in September 2011 at OpenWorld. Oracle removed the NoSQL criticism from its website but (more...)

The Twelve Days of NoSQL: Day Seven: Schemaless Design

On the seventh day of Christmas, my true love gave to me Seven swans a-swimming. As we discussed on Day One, NoSQL consists of “disruptive innovations” that are gaining steam and moving upmarket. So far, we have discussed functional segmentation (the pivotal innovation), sharding, asynchronous replication, eventual consistency (resulting from (more...)

The Twelve Days of NoSQL: Day Six: The False Premise of NoSQL

On the sixth day of Christmas, my true love gave to me Six geese a-laying. The final hurdle was extreme performance, and that’s where the Dynamo developers went astray. The Dynamo developers believed that the relational model imposes a “join penalty” and therefore chose to store data as “blobs.” (more...)

The Twelve Days of NoSQL: Day Five: Replication and Eventual Consistency

On the fifth day of Christmas, my true love gave to me Five golden rings. By now, you must be wondering when I’m going to get around to explaining how to create a NoSQL database. When I was a junior programmer, quite early in my career, my friends and I were assigned (more...)

Presenting at UKOUG Tech13 Conference

It’s been a while since I put anything on this blog, most likely down to a combination of being overly busy in my previous life at UKOUG and not having anything to say that couldn’t be said in 140 characters.

Anyway, I’ll be at the UKOUG Tech13 Conference in Manchester (more...)

DBA or Developer?

I've always considered myself a developer and a LOWER(DBA). I may have recovered perhaps one database and that was just a sandbox, nothing production worthy. I've built out instances for development and testing and I've installed the software a few hundred times, at least. I've done DBA-like duties, but (more...)

Upgrade to Oracle Enterprise Manager Cloud Control 12c Release 3 (

Just a quick wrap up on EM12cR3 upgrade. I have to say that I was pleasantly surprised that everything went so smooth. I didn’t expected anything else, but with so how many products and components we have there I got few things in mind. The version I got was already (more...)

Improving data move on EXADATA V


This is the last post in this series and I’ll not introduce anything new here, but rather just summarise the changes explained and talk a bit about the value the solution delivers to the organisation.

Let’s first review the situation we faced before implementing the changes.

The cost of writing (more...)

Demystifying Big Data for Oracle Professionals

Ever wonder about Big Data and what exactly it means, especially if you are already an Oracle Database professional? Or, do you get lost in the jargon warfare that spews out terms like Hadoop, Map/Reduce and HDFS? In this post I will attempt to explain these terms from the perspective (more...)

Improving data move on EXADATA IV

Reducing storage requirements

In the last post in this series I talked about how we sped up the move of data from operational to historical tables from around 16 hours down to just seconds. You find that post here.

The last area of concern was the amount of storage this (more...)

Improving data move on EXADATA III

Moving to history tables

In the last post I talked about how we made the speed of actually writing all those log-records much faster. It has to date been so fast that no a single report of a problem has been filed. you find that post here.

Once the data (more...)

Improving data move on EXADATA II

Writing log records

The last post in this series introduced the problem briefly. You find that post here.

In this post I’ll talk about the changes made to make that writing of log records fast enough. There were 50 million records that was written. Each of them pretty much in its (more...)