The Hitchhiker’s Guide to the EXPLAIN PLAN: The story so far (Part 11–23)

On the Toad World site, I’m writing a series of blog posts and Wiki articles on the subject of EXPLAIN PLAN. I’m using EXPLAIN PLAN as a motif to teach not just SQL tuning but also relational theory, logical database design, and physical database design. In a year’s time, I hope to have enough material for […]

Fedora PostgreSQL Install

Somebody asked how to put PostgreSQL on my Fedora image with Oracle Database 11g and MySQL. It’s fairly simple. You can check for the current download at yum.postgresql.org and then download it like this as the root user:

yum localinstall http://yum.postgresql.org/9.3/fedora/fedora-20-x86_64/pgdg-fedora93-9.3-1.noarch.rpm

You should see the following output when the download is (more...)

The Hitchhiker’s Guide to the EXPLAIN PLAN: The story so far

Part 1—DON’T PANIC: Even experienced application developers may not understand EXPLAIN PLAN output. As the great Renaissance artist Leonardo da Vinci said in his dicourse on painting: “Those who are in love with practice without science are like the sailor who gets into a ship without rudder or compass, who is never certain where he […]

Editor’s Choice award at ODTUG Kscope14: NoSQL and Big Data for the Oracle Professional

My paper on NoSQL and Big Data won the Editor’s Choice award at ODTUG Kscope14. Here are some key points from the paper: The relational camp made serious mistakes that limited the performance and usefulness of the relational model. NoSQL is based on the incorrect premise that tables in the relational model must be mapped to […]

Is your database secure? Are you sure? Are you *really* sure?

Credit for finding this bug is given to Daniel Ekberg – https://www.linkedin.com/profile/view?id=10435009. He got the official credit given by Oracle Corp for helping out with security related bugs in the January 2014 CPU. He found the bug and had the tenacity to track down and prove that it was a bug and not just a flaw in the logging mechanism where this first was indicated to occur.

Today is the day when (more...)

The Hitchhiker’s Guide to the EXPLAIN PLAN (Act II)

Over at ToadWorld … Part 5: SQL Sucks! Part 6: Trees Rule Part 7: Don’t pre-order your EXPLAIN PLAN Part 8: Tree Menagerie The story so far: A relational database is “a database in which: the data is perceived by the user as tables (and nothing but tables)  and the operators available to the user for (for […]

My MySQL database impressions

I have been in the data and database world for over a decade now, working with mainly Oracle and data integration projects with Salesforce.

I have also spent time working with MySQL a relational database with open source roots, now part of Oracle. In this post I want to talk about my impressions of MySQL and some tips and tricks I learned working with it.

First and for all, you will have to be ready (more...)

The people behind the NoCOUG Journal

Now in its 28th year, the NoCOUG Journal is the oldest Oracle user group publication in the world. No other small user group in the world has a printed journal. Most large user groups do not have printed journals either. But little NoCOUG does. I am the editor of the NoCOUG Journal and—I must confess—I get sad when I see […]

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:
  • DISABLED
  • RETRY SCHEDULED
  • SCHEDULED
  • RUNNING
  • COMPLETED
  • BROKEN
  • FAILED
  • REMOTE
  • SUCCEEDED
  • CHAIN_STALLED

When does Oracle Scheduler change STATE to be BROKEN?
Then, (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 (12.1.0.3)

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...)

New interesting feature of Oracle 12c

This looks like an interesting feature of Oracle 12c. I’m still not sure about the security implications but it does say interesting things about pure network monitoring security tools. Now, more than ever, what you see on the network can be something completely different than what runs on the database. So, you can see a […]

Improving data move on EXADATA V

Wrap-up

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...)

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...)