Materialized views: fast refresh, complete refresh or recreate?

Have you ever wondered why it takes a century to completely refresh your materialized view? I did, so I did some testing.

Recently I was asked to support a customer whose database was extremely slow. As it turned out, some indexes had been created on a materialized view and that view was being refreshed. Soon I found that a large ‘delete from’ job was running, which turned out to be part of the complete refresh.

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Oracle InMemory compared to indexing

In August 2014 Oracle released its RDBM 12.1.0.2 with a potentially useful and exiting new option: Database InMemory. Upon reading about it it became clear to me that this is a powerful option, worth examining deeper.

This blog will briefly describe what InMemory is and what it isn’t. The emphasis however is on practical examples. I didn’t have a real database at hand for some ultimate real life experience, but a local (more...)

Cloud Control authorization with Active Directory

About 2 months ago I wrote an article about setting up user authentication in Cloud control, based on their account in the Active Directory. As promised, here is the second part describing Cloud Control authorization with Active Directory.

A small recap about why this could be useful:

If your company is preferring Microsoft Active Directory (further named AD) as a source of truth (or at least you´re trying to) you should be using the AD (more...)

Oracle Restart to autostart your oracle database, listener and services on linux.

Half a year ago, my colleague Remco wrote an article on auto starting the listener and the databases after a host reboot. As usual with Oracle, there are several solutions. In a previous job, I learned to appreciate Oracle Grid infrastructure to do the same. And then some more.

Oracle Grid Infrastructure can be downloaded and used for free. It serves many purposes, especially for ASM and RAC,but as it turns out, it can be (more...)

PostgreSQL Database

How time flies, last March I explained how to install and configure PostgreSQL on Windows. It was my intent to start posting more content on PostgreSQL but I was distracted by another writing commitment on Oracle Database 12c PL/SQL Advanced Programming Techniques, which should be available in November. It tempted me away from PostgreSQL because I got to write about how to use Java inside Oracle Database 12c, which was fun. Having (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...)

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 […]

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...)