ODTUG ADF and Database Community Meetup at Oracle OpenWorld


Tuesday, September 20, 2016
5:00 PM to 7:00 PM
138 Minna Street, San Francisco, CA (map)

Oracle OpenWorld is a time for us to join together and learn all about what Oracle has to offer.  But let’s get real, it’s always nice to get free beer.  To help show us a good time here in San Francisco, our good friends in the Oracle ADF and Database developer group are planning a Oracle Developers (more...)

Denial of Service (DoS) attacks continue

It’s frustrating to have to spend time jumping off into web security and wordpress configurations when there are so many other things that are important to be doing. Today the DoS continued and the Jetpack solution didn’t seem to work. The other two solutions from Digital Ocean didn’t seem reasonable. One was to re-install wordpress with there install version. Nice that they offer a better security protected version but I didn’t feel like re-installing my (more...)

Denial of Service (DoS) attach on this site

This site had been running for a years with no big issues.
I had performance and system saturation issues about 3 years ago and then move the site to DigitalOcean.com.

They are inexpensive and the performance is awesome.

Then last Monday and every day since the site had been going down.
Simplest “solution” for me was just to get on and bounce the machine.

That cleared it up.

After this went on for a (more...)

Speaking at OOW 2016 on Sunday on Active Session History

Session ID: UGF3110

Advanced Active Session History Analytics
Moscone West—3020
09/18/16, 03:30:00 PM – 04:15:00 PM



SQLfail? SQLwin!

update sqlfail 
set    last_posting_date = date'2016-08-18';

It’s been a while since I’ve published here. You see, I’ve been kind of busy.

Back in January 2015 I was lucky enough to join Oracle as part of their Developer Advocate team. My focus is SQL.

You see I love working with SQL. And I love helping others. So joining the Developer Advocates was a great chance to combine these passions :)

Which leads some to ask:

Why is your site (more...)

How to resolve missing dependency on exadata-sun-computenode-minimum

I’ve been really busy last few months – except spending a lot of time on M25 I’ve been doing a lot of Exadata installations and consolidations. I haven’t posted for some time now but the good news is that I got many drafts and presentations ideas.

This is a quick post about an issue I had recently. I had to integrate AD authentication over Kerberos on the compute nodes (blog post to follow) but had (more...)

APEX & JavaScript, the modular way

On the 28th of July, I presented this topic at Kscope16. It was a great conference and if you ever have the chance to visit, definitely do so.

This approach is useful when you have to deal with a lot of JavaScript code in your application. The main goal is to create reusable components, which help you to speed up development and keep things nice and tidy. Why?

  • Hide implementation details of external JavaScript libraries/ (more...)

How to make Apple Airport wifi routers do remote logging.

This is a blog not related to Oracle products in any way.

Remote logging.
This post is specific to apple Airport Extreme and Express wifi routers. However, in general: if you have multiple (unix/linux) servers, it makes sense to centralise the (sys)logging of these servers, in order to get a better overview on what is happening on these servers. I would want to go as far as saying that if you don’t you are simply (more...)

Digital Transformation Partner of the Year!

UKOUG Awards

We are excited to announce AuraPlayer has been shortlisted for UKOUG’s 2016/2017
Digital Transformation Partner of the Year! This award provides recognition to Oracle Partners for their contributions to Oracle users by promoting digital transformation.

It has been such an incredible year watching our customer’s applications change from gray screens nailed onto a desktop to cutting-edge mobile applications. Digital transformations have been occurring in all industries including field service, public-sector and retail. We are so (more...)

Five Minutes That Will Make Users Happy

My kitchen has a very nice range hood over the cooktop. It has a powerful  fan and beautiful brushed steel finish. And it has a user experience like most IT systems: Lousy.

Let’s think about what a range hood does. It has two main functions:

  1. Start the fan to extract grease and fumes
  2. Turn on the light over the cooktop

Because of the shape of a range hood, the buttons to operate it are typically (more...)

Join predicate pushdown

When a query contains a regular or inline view, there are 3 basic strategies for the optimizer to choose from:

1) merge the view (no “VIEW” operation in the plan)
2) instantiate the view as the whole and join it to the rest of the query (the plan shows a VIEW “operation”)
3) push join predicates inside the view (the plan shows “VIEW PUSHED PREDICATE”).

The last strategy in that list is similar to a (more...)

Join cardinality

In my previous post I showed an example of how a query’s performance can be improved using the waste minimization technique. My focus was primarily on identifying and enforcing the correct plan, but I received some questions regarding the root cause of the problem: why the optimizer came up with a wrong join order? It’s a very interesting question, and it deserves a separate post so that it could be explored in detail.

Let’s take (more...)

SELinux blocked my .Xauthority

I was attempting to install an OEM management server on a new host in the lab using runInstaller.  Of course the installer is an X-windows app so I need to configure port forwarding to get the display back to MacBook.

I added the new host and its bastion to my ~/.ssh/config file to set up port forwarding:

ConnectTimeout 60
StrictHostKeyChecking ask
ProxyCommand none
UserKnownHostsFile ~/.ssh/known_Hosts
User oracle

Host newlaboms. (more...)

Subtleties – Part 3 (more workarounds for COLLECT DISTINCT in PL/SQL)

In Part 1 we saw that the SQL function COLLECT with the DISTINCT option is not natively supported in PL/SQL, and saw two workarounds – using dynamic SQL and using the SET function.
In Part 2 we saw that the SET function can operate on Nested Table but not on Varray.
In this post we’ll see two more workarounds.

Inline View

We can first remove the duplicates in an inline view, and then use the (more...)

AWR analysis: another case study

A few weeks ago, I received a request to review an AWR report for a database suffering from instance-level performance issues. Here are the the key parts of that report (with some masking):


DB Name         DB Id    Instance     Inst Num Release     RAC Host
------------ ----------- ------------ -------- ----------- --- ------------
XXXX           XXXXX     XXXXX               1  NO  XXXX

              Snap Id      Snap Time      Sessions Curs/Sess
            --------- ------------------- -------- ---------

Moving to Seattle! Our beautiful rental available in San Francisco


More news coming, but for now, we (family and I) are moving to Seattle! We will be giving up our gorgeous rental house in San Francisco thus it will be available to the next lucky family.

Elegant mediterranean style family home on a quiet tree lined street in a sweet residential neighborhood just minutes from downtown and the Peninsula. 

Photos of house


Perfect location for commuting to Peninsula on 280  or downtown SF (more...)

OEM Preferred Connect Strings

You can specify a connection string for database targets in two ways:  fill in the blanks and let OEM create the connection string (my preference) or paste a Preferred Connect String on the bottom of the page.


Our default setting in our shop is to use multi-threaded servers. On the rare occasion when we need to change if, we paste the connect string from tnsnames.ora in place and add the SERVER=DEDICATED parameter.

Some things to (more...)

Dropping constraint… what about the index?

In a recent release that I’ve been working on, we had to drop and recreate some of the unique/primary key constraints (due to columns being added into the constraint) on some of our tables.

Prior to working in this team, I had only ever come across explicitly creating the indexes for a table, similar to:

create table test_explicit_index (col1 number,
                                  col2 varchar2(30),
                                  col3 date);

create unique index col1_exp_pk on test_explicit_index (col1);

We can see the (more...)

Moving from PeopleSoft to the Oracle Cloud

Those of you who know me will know that I’m working at Cedar and we’re moving from PeopleSoft to the Oracle Cloud. I won’t talk about the company’s journey, but more how I’ve found the transition personally.

In brief, there’s a lot to learn.

Data Model knowledge

In the PeopleSoft world, once you know the table structures you could work significantly faster. Whether you were writing an SQR, an App Engine, an XMLP report, a (more...)

Oracle Audit Control part 3 – OS files

Just realized that I wrote a follow-up to Part 2 2 years ago and never posted it! So here’s the stripped-out key facts to round off auditing control a bit more:

Deleting O/S audit files is, like, totally necessary. In Oracle 12C (12.1), they are created by default as AUDIT_SYS_OPERATIONS defaults to TRUE now, so you are going to be filling up your AUDIT_FILE_DEST whether you realized it or not.

[NOTE: In theory, this (more...)