Securefile in 12c – part 2

In a previous post, I noted that the parameter db_securefile changes from PERMITTED in 11g, to PREFERRED in 12c.  Jonathan Lewis raised the interesting question of what happens when you upgrade to 12c from 11g, where a partitioned table may already have some basicfile LOBs defined.  This blog post explores that.

We’ll start with “PERMITTED” mode, and create a table with two partitions. We can see that at table level and partition (more...)

Using Tiered Storage in Alluxio


Alluxio is an open source memory speed virtual distributed storage system. An brief overview of Alluxio has been covered in a previous blog. This post will cover one of the most powerful features of Alluxio, which is its tiered storage capabilities.

Speaking at OOW 2016: Write powerful scripts with EMCLI

This will be my first time to attend Oracle Open World, and I’ll speak about Enterprise Manager Command-Line Interface (EMCLI) Scripting” on User Group Sunday. I already presented it on several conferences, heard people’s feedback and modified the content to improve my presentation. Now I will focus more on practical information, share sample scripts that can be used in real world scenarios. Hope to see you there!

Session ID: UGF3543
Session Title: Oracle Enterprise Manager (more...)

Oracle Open World 2016 – What GoldenGate sessions are there?

Well, it is that time of year again; the streets of San Francisco will be crowded with members of the Oracle community! As everyone in the Oracle community descends onto the bay area, there will be excitement about the things that will be announced this year. Sure a lot of it is going to be about “cloud” and what direction Oracle is taking with their “cloud” strategy. Besides, “cloud” there will be a lot of (more...)

Happy birthday to …. well … us :-)

Last year on September 1, the AskTom site was resurrected under Apex 5 with myself and Chris Saxon manning the fort to deliver as much value to the Oracle community as the esteemed previous custodian of the site did in the many years preceding us.

In the last year, we have

  • answered ~2,500 questions
  • taken and followed up on ~3000 reviews

It’s great fun and very rewarding working on the AskTom site.  We get (more...)

Raspberry Pi- Common Configuration Issues

The following issues in this post are common challenges experienced by Raspberry Pi, (RPI) owners and I’m consistently frustrated with the ridiculous answers out on the internet for them!  No fear, trusty Raspains!  I’m here to offer you the correct and [pretty easy] answers that will actually fix the problems and won’t lead you to searching for hours on the internet.

We techies know that no matter what, going back to (more...)

How Many ASM Disks Per Disk Group And Adding vs. Resizing ASM Disks In An All-Flash Array Environment

I recently posted a 4-part blog series that aims to inform readers that, in an All-Flash Array environment (e.g., XtremIO), database and systems administrators should consider opting for simplicity when configuring and managing Oracle Automatic Storage Management (ASM).

The series starts with Part I which aims to convince readers that modern systems, attached to All-Flash Array technology, can perform large amounts of low-latency physical I/O without vast numbers of host LUNs. Traditional storage (more...)

Delphix Sessions at Oracle Open World 2016!

Oracle Open World 2016 is almost here…where did the summer go??


With this upon us, there is something you attendees need and that’s to know about what awesome sessions are at Oracle Open World from the Delphix team!  I gave my options up as is the tragedy of switching companies in late spring from Oracle, but you can catch some great content on how to reach the new level (more...)

Conference Report: NoCOUG 2016 summer conference at Chevron

The Northern California Oracle Users Group (NoCOUG) is a volunteer-run 501(c)(3) organization and the longest-running Oracle users group in the world. It organizes a full-day conference every quarter and publishes a quarterly Journal. The summer conference at Chevron was the 119th quarterly conference organized by NoCOUG.(read more)

An introduction to Oracle PL/SQL for beginners

PL/SQL offers the entire suite of structured programming mechanisms, such as condition checking, loops, and subroutines, as shown in the following figure. (read more)

An excellent review of where we are, where it all came from, and where we are going‏

About the book he reviewed for the August 2016 issue of the NoCOUG Journal, Brian had this to say: “You should read this book. If you are starting out in a database-related career—which I think includes most, if not all, programming jobs—or if you are changing fields within the broader database field, the information in this book will be very helpful in the interview and on the job. I learned a great deal about things (more...)

A day in the life of a problem solver

P.O.I.S.E.D. is the acronym I invented for the performance tuning method described by Chris Lawson in The Art and Science of Oracle Performance Tuning; it stands for Problem, Observation, Interpretation, Solution, Execution, and Documentation.(read more)

Parallel_index hint

Prompted by a recent OTN posting I’ve dug out from my library the following demonstration of an anomalty with the parallel_index() hint. This note is a warning about  how little we understand hints and what they’re supposed to mean, and how we can be caught out by an upgrade. We’ll start with a data set which, to match a comment made in the origina posting rather than being a necessity for the demonstration, has an (more...)

After OpenWorld…

Don’t forget that there’s lot of great content still to come your way throughout the rest of the year.

I’ll be part of the OTN Tour in Bangalore, Sydney and Brisbane.

And for a change of pace… I’ll be doing a keynote  at UKOUG !  (I’m the person in the list below who isn’t a senior director or vice president Smile)

Hope to see you at some or all of these events.



Resizing ASM Disks On Modern Systems. Real Application Clusters Doesn’t Make It Any More Difficult. An XtremIO Example With RAC.

My recent post about adding space to ASM disk groups by resizing them larger, as opposed to adding more disks, did not show a Real Application Clusters example. Readers’ comments suggested there is concern amongst DBAs that resizing disks (larger) in a RAC environment might somehow be more difficult than in non-RAC environments. This blog entry shows that, no, it is not more difficult. If anything is true it is that adding disks to ASM (more...)

Simple Cold Backup using tar

At times, I find it much simpler to shutdown my test database and create cold backup which will allow me to revert from any errors.

$ echo $ORACLE_SID

$ tar -cvzf /media/sf_OracleSoftware/$ORACLE_SID_$USER_`hostname -s`_backup.tar.gz .

$ ll /media/sf_OracleSoftware/DB01_oracle_arrow_backup.tar.gz
-rwxrwx---. 1 root vboxsf 382676286 Aug 28 13:09  (more...)

Started at Amazon! … want to join me?




(Disclamer: any opinions expressed here are fully my own and not representative of my employer)


photo by alvaroprieto  (cc 2.0)

Super excited to be working at Amazon on my passion which is performance data visualization and database monitoring. Suffice it to say this is the most excited I’ve been about work in my career and I’ve had ample opportunity to work on database performance in the past such as at (more...)

Oracle Database Cloud (DBaaS) Performance Consistency – Part 3

This is the third part of this installment, comparing the performance consistency of the DBaaS cloud offering with a dedicated physical host. This time instead of burning CPU using logical I/O only (see part 2) the test harness executes a SQL statement that has to perform physical I/O mostly, and to be more precise this round is a read-only test, so doesn't include any modification to data (except the logging and any other background (more...)

Smarter DG Broker in Oracle 12c

In Oracle 11G, DG Broker needed to be told whether the standby database was physical or logical. The command to add database in 11G was something like this:



Oracle 12c is definitely smarter and can figure it out on its own. The “ADD DATABASE” syntax is simpler:

DGMGRL for 64-bit Windows: Version – 64bit Production

Copyright (more...)

Being An ACE – What’s In It For THEM?

I’ve been an Oracle ACE for about 7 years now, and have never written about it. Other Oracle ACEs have written about this over the years (like this post by Tim Hall), so I didn’t feel the need to write my own post. Lately, I’ve been thinking about the Oracle ACEs from a different perspective, … Continue reading Being An ACE – What’s In It For THEM?