EM13c: Unauthorized Access to Performance Pages

I noticed an interesting security problem (exploit?) on Oracle Enterprise Manager Cloud Control 13cR2 (I tested on EM13cR1 and it also exists on there). When you create an Enterprise Manager administrator, you need to grant some special privileges to that administrator if you want them to access the performance pages, but it seems there’s an alternative way to access the performance pages without requiring extra privileges.

Let’s say I created a new administrator with (more...)

DOAG 2016

I had a great time at DOAG 2016. It’s one of the best run conferences I’ve been to! I did a quick cameo during the keynote to talk about performance in Oracle’s cloud. Nothing like being on stage with a guy wearing a tie. :) Thanks Andrew for inviting me to say a few words.


That was fun! Here’s a link to the paper I referenced:

Oracle Cloud Performance Testing Results


Then I did (more...)

Which SQLcl build am I running?

This is something I discovered a few minutes ago by pure coincidence and it’s not documented as far as I know.


You can enter version or show version and it will tell you the exact SQLcl build that you’re executing.

Filed under: Oracle, SQLcl Tagged: Oracle, SQLcl

Advanced Oracle memory profiling using pin tool ‘pinatrace’

In my previous post, I introduced Intel Pin. If you are new to pin, please follow this link to my previous post on how to set it up and how to run it.

One of the things you can do with Pin, is profile memory access. Profiling memory access using the pin tool ‘pinatrace’ is done in the following way:

$ cd ~/pin/pin-3.0-76991-gcc-linux
$ ./pin -pid 12284 -t source/tools/SimpleExamples/obj-intel64/pinatrace.so

The pid is (more...)

#DOAG2016 wrap up


Another DOAG is over and here are my summary.

Day 1

Unfortunately the early train from duesseldorf arrives not before 9:30, so I missed the first morning slot. But on the other hand I this was the slot where I had to decide between 8 presentations, which I’m interested in.

The first soft skill presentation was about creative techniques beyond brain storming. The mentioned 3 techniques was all unknown for me, maybe I give it (more...)

Oracle Midlands : Event #18

Don’t forget Oracle Midlands Event #18 next week!


If you live near, please show your support for the event and come along. It’s free thanks to the sponsorship by RedStackTech.



Oracle Midlands : Event #18 was first posted on November 17, 2016 at 4:06 pm.
©2012 "The ORACLE-BASE Blog". Use of this feed is for personal non-commercial use only. If you are not reading this article in your feed reader, then the (more...)

Introduction to Intel Pin

This blogpost is an introduction to Intel’s Pin dynamic instrumentation framework. Pin and the pintools were brought to my attention by Mahmoud Hatem in his blogpost Tracing Memory access of an oracle process: Intel PinTools. The Pin framework provides an API that abstracts instruction-set specifics (on the CPU layer). Because this is a dynamic binary instrumentation tool, it requires no recompiling of source code. This means we can use it with programs like the Oracle (more...)

Playing with SUBSTR and INSTR

hawk:(SYS@hawk):PRIMARY> r
  1  SELECT handle,
  2  SUBSTR(handle, INSTR(handle,'/',-1)+1)                extract_last_field,
  3  SUBSTR(handle, 1, (INSTR(handle,'/',-1,1)-1))         remove_last_field,
  4  SUBSTR(handle, 1, (INSTR(handle,'/',1,2))-1)          extract_first_field,
  5  SUBSTR(handle, INSTR(handle,'/',1,2), length(handle)) remove_first_field
  6* FROM v$backup_piece_details



hawk:(SYS@hawk):PRIMARY> r
  1  SELECT name,
  2  SUBSTR(name, INSTR(name,'/',-1)+1)              extract_last_field,
  3  SUBSTR(name, 1, (INSTR(name,'/',-1,1)-1))       remove_last_field,
  4  SUBSTR(name, 1, (INSTR(name,'/',1,2))-1)        extract_first_field,
  5  SUBSTR(name, INSTR(name,'/',1,2),  (more...)

Creating a RAC cluster using Ansible (part 1)

In my previous blog post i explained how Vagrant can be used to create a 2-node VM environment for deploying a RAC cluster on it. In this post i want to dive into how to actually do the RAC install using ansible so you can easily create a RAC test environment on eg. your laptop.

I have created a git repo with the files that i am using for this blog post, this git repo (more...)

Creating Oracle Big Data Lite VM on Proxmox

The Oracle Big Data Lite VM available on Oracle technet, provides a pre built environment for learning about a number of key Oracle products, including Oracle 12c database, Big Data Discovery and Data integrator as well as Cloudera Distribution – Apache Hadoop (CDH 5.8.0).

The download ultimately delivers an OVA “appliance” file for use with Oracle VirtualBox, but there isn’t anything to stop you running this as a VM on proxmox 4, (more...)

Cloud Control 13c Release 2 (13cR2) : It’s Alive!

o-enterprisemgr-13c-clr-2769481I delayed our upgrade from Cloud Control 13cR1 to 13cR2 until I finished all my travelling. It’s not really fair to make a major change then swan off round the world. 🙂

Yesterday was the day. I got in and started the upgrade, following the process I documented here and it worked. 🙂


I guess I shouldn’t be surprised. I had tested it all at home anyway.

We now have Cloud Control 13cR2 monitoring all out Dev and (more...)

Redo a blogpost

This blogpost is about the Oracle redo log structures and redo efficiency in modern Oracle databases. Actually, a lot of subtle things changed surrounding redo (starting from Oracle 10 actually) which have gone fairly unnoticed. One thing the changes have gone unnoticed for is the Oracle documentation, the description of redo in it is an accurate description for Oracle 9, not how it is working in Oracle 10 or today in Oracle 12.1.0. (more...)

My session at #AIOUG #Sangam16 – Transition from Oracle DBA to Big Data Architect

Big thanks to all those who turned up for my early morning session on Saturday Nov 12th, 2016. I know it was a tough call after a week’s work but thanks for making the right decision. A full-house is an extreme delight for a speaker. You can download the session deck either from the Sangam … Continue reading

Oracle ACE Program : Some more opinions

I’ve written about the Oracle ACE Program a number of times over the years, including the following.

I’ve also recorded a video on the subject.

Some things have come up in conversation a few times recently that lead me to believe there are some misunderstandings about what the label “ACE” means and (more...)

Optimizer Compatibility, Short Pants and Hot Sauce

OK, so I’m all over the map, (technology wise) right now.  One day I’m working with data masking on Oracle, the next it’s SQL Server or MySQL, and the next its DB2.  After almost six months of this, the chaos of feeling like a fast food drive thru with 20 lanes open at all times is starting to make sense and my brain is starting to find efficient (more...)

Distributed Trap

Here’s an interesting (and potentially very useful) observation from an OTN database forum thread that appeared at the end of last week. It concerns the problems of pulling data from remote systems, and I’ll start by building some data:

rem     Script:         remote_insert_2.sql
rem     Author:         Jonathan Lewis
rem     Dated:          Nov 2016
rem     Last tested

create table t1
with generator as (

Yes, Storage Arrays Can Deduplicate Oracle Database. Here Is Exactly Why It Doesn’t Matter!

I recently had some cycles on a freshly installed Dell EMC XtremIO Storage Array. I took this opportunity to prepare a blog entry about the never-ending topic of whether or not storage arrays are able to reduce physical data capacity through deduplication of blocks in Oracle Database.

Of Course There Is Duplicate Data In Oracle Datafiles

Before I continue, let me say something that may come as a surprise to you. Yes, Oracle Database has (more...)

Oracle 12cR2: Database parameters

For those in a desperate need to learn all 4841 database parameter variations of the…

Oracle DBaaS database available

Just created by first Extreme Performance database in the cloud.oracle.com. So just after a…

Oracle Manuals available now!

Have a look what’s new and cool in the full Oracle manuals / documentation…