Result Cache

Yesterday I thought I’d spend half an hour before breakfast creating a little demonstration of a feature; some time about midnight I felt it was time to stop because I’d found enough bugs to drive me up the wall. Today’s short post is just little warning: be VERY careful what you do with the PL/SQL result cache – if you use the results of database queries in the cache you may end up with inconsistent (more...)

RAM is the new disk – and how to measure its performance – Part 2 – Tools

In the previous article I explained that the main requirement for high-speed in-memory data scanning is column-oriented storage format for in-memory data. SIMD instruction processing is just icing on the cake. Let’s dig deeper. This is a long post, you’ve been warned.

Test Environment

I will cover full test results in the next article in this series. First, let’s look into the test setup, environment and what tools I used for peeking inside CPU hardware.

I (more...)

Oracle 12c RAC on Oracle Linux 7 using VirtualBox

virtualbox I’m a little late to the party here, but I’ve finally got round to updating the VirtualBox 12c RAC article for Oracle Linux 7.

It’s not hard to do these VirtualBox RAC installations, but I find the process of putting the articles together really tedious. There are so many screenshots. That’s why it’s taken a while to build up the motivation to (more...)

My nominations for the Oracle Database Developer Choice Awards 2015

I'm honored to have been nominated for the Oracle Database Developer Choice Awards 2015, in no less than three (!) categories: PL/SQL, Application Express (Apex) and Oracle REST Data Services (ORDS).

Here's a short video that explains what the Oracle Database Developer Choice Awards are all about:

If you are a regular reader of my blog, you are probably familiar with my contributions to the Oracle Database Developer community, but here is (more...)

Tracing Data Lineage and Impact Analysis in Oracle Enterprise Metadata Management 12c

At the beginning of the year, I wrote a couple of posts about Oracle Enterprise Metadata Management, one about how to install the tool and another one explaining the harvesting (importing) and stitching (relating) processes. A lot of things have happened since then, including a new version of OEMM released on May with some nice features as HTML 5 support, a workflow for business glossary and including the concept of groups in security.

OEMM is the (more...)

Log Buffer #441: A Carnival of the Vanities for DBAs

This Log Buffer Edition dives deep into the ocean of blogosphere and surfaces with some cool blog posts from Oracle, SQL Server and MySQL.


  • Lets Talk DB Perth
  • The Fundamental Challenge of Computer System Performance
  • Index Advanced Compression: Multi-Column Index
  • Middleware Diagnostics Advisor (MDA) Setup
  • Most people are now aware that in 12c, a VARCHAR2 has been extended from a maximum size of 4000 to 32767 bytes.

SQL Server:

Exadata X5 PDU – CLI already in use

Exadata X5-2 and X4-8B racks are delivered with the “Enhanced” PDU metering units connected via the Cisco switch. Although the documentation says they should have static addresses, they don’t. You need to configure them manually using serial console connection, this is described in my earlier post here.

However if you forget to exit the serial console connection to the PDU and then try to login using SSH later you’ll get the following message:

login as:  (more...)

SANGAM15 – See you there!

I mentioned my Oracle OpenWorld 2015 trip in a previous post. Yesterday evening I picked up my passport with my lovely new India visa in it!

The talks are written. The flights are booked. The hotel is booked. I have a visa. So that’s me sorted for SANGAM15 in November! :)

It’s going to be a rather hectic few days. I fly out, do the 2 day conference, then fly straight home. It looks like I (more...)

BI Publisher Tips and Techniques

A colleague of mine asked recently if we had any <evil term alert>best practices</evil term alert> for BI Publisher, the latest and greatest reporting tool we use within Enterprise Manager (the old tool, Information Publisher, is of course also still supported but this post is relevant to BI Publisher). As you would well know if you’ve been following my posts or heard me presenting at conferences, <evil term alert>best practices</evil term alert> is a term (more...)

Honored to be an Oracle Developer Choice Awards – Application Express Finalist

Originally posted on TH TECHNOLOGY:
I am honored to be a finalist in the Oracle Database Developer Choice Awards, in the Oracle Application Express category. I am most impressed with my fellow finalists – amazing devotion to helping the APEX community – and humbled to be included in such a crowd.  Congratulations to all! Please…

Optimizer statistics – parse time statistics aggregation

It’s getting harder and harder to find time for writing. Anyway, this post stays from a long time in my draft so, I think is time to finish and post it. That one is the last one from the optimizer statistics series. For now, of course :) After describing the horror around the way that […]

Part 3: Comparing Oracle Cloud Database Backups Options

Comparing Oracle Database Backup Service (ODBS) and Oracle Secure Backups (OSB) to Amazon Web Services (AWS)

This is part 3 of a 3 part series on “Getting Started with Oracle Cloud Backups”.

  • Part 1 covers setting up RMAN to backup directly to the new Oracle Cloud Database Backup Service (ODBS).
  • Part 2 covers setting up RMAN to backup directly to the cloud using Amazon Web Services (AWS) Simple Storage Service (S3).
  • Part 3 compares and (more...)

Part 2: Oracle Cloud Backups to AWS S3

Getting Started with Oracle Cloud Backups – Amazon Web Services (AWS)

This is part 2 of a 3 part series on “Getting Started with Oracle Cloud Backups”.

  • Part 1 covers setting up RMAN to backup directly to the new Oracle Cloud Database Backup Service (ODBS).
  • Part 2 covers setting up RMAN to backup directly to the cloud using Amazon Web Services (AWS) Simple Storage Service (S3).
  • Part 3 compares and contrasts the two services.



Exadata Software is Released

Good new features announced, such as finding Flash Cache and Flash Log statistics on AWR, automatic ASM data redundancy check even shutting down a storage server by pressing the power button or through ILOM, preventing Flash Cache population in cell to cell rebalance, disabling SSH on Storage Servers and running CellCLI commands from Compute Nodes via new ExaCLI utility. Find details in the MOS

Better Data Modeling: Showing Super & Sub Types in #SQLDevModeler (SDDM)

So this started with a not so innocent tweet from Jeff Smith: @GuillaumeSL i’m betting @KentGraziano could answer your question right away — Jeff Smith (@thatjeffsmith) September 14, 2015 // Well, I sort of answered at least part of the question (eventually),  but along the way the topic of using super types and sub types […]

Recommendations to Address Cloud Performance Issues via EM12c

So I’m going to start this post with an admission-  I don’t have access to a cloud environment to test this out, but I know what I would do first if I experienced slow response time on database creation or cloning via EM12c to the cloud and I would like to at LEAST post what I would do to give others the chance to test it out and see if it offers them some (more...)

ORDIM – Oracle Multimedia – Invalid after upgrade

ORDIM – The Oracle Multimedia component might be in INVALID state after the database upgrade to 12c. While I was testing the upgrade on test server, received below errors after the completion.

Serial   Phase #:69 Files: 1 Use of uninitialized value $gsRTInclusion in concatenation (.) or string at line 1500.
    Time: 49s

Phases [0-73]         End Time:[2015_08_08 08:06:45]

Grand Total Time: 4848s



DBMCLI for Exadata Database Servers

Monitoring database servers for hardware failures in Exadata used to be an issue. We have CELLCLI for storage servers where we can make many administration tasks and set SMTP configuration to receive e-mail for hardware failures. For the DB servers we were able to configure SMTP Client on database server's ILOMs for email alerts but it was not a straightforward and easy configuration as we do in

Submit an Abstract to RMOUG Training Days 2016!

As the Training Days Director for Rocky Mountain Oracle User Group, one of my tasks is not just running the conference for RMOUG, but also promoting it.

RMOUG Training Days was the first conference I ever attended, (2004) and the first one I ever presented at, (2009.)  Its one of the reasons my career is where it is now and how I stayed in touch with the man who is now my partner (more...)

Middleware Diagnostics Advisor (MDA) Setup

One of the areas I’ve been exploring recently is the setup and use of the Middleware Diagnostics Advisor, more commonly known as MDA. MDA is an advisor in EM12c that analyzes the entire stack and provides diagnostic findings by identifying root causes for any problems it discovers. It correlates and analyzes the input and offers advice on how to resolve the problem. For example, it can help you identify that slow SQL statements or a (more...)