KScope14 – on my way home

For some reasons I got lounge access here at Seattle airport when going home fra KScope14. So I can use the last couple hours here lounging comfortably writing a few words about an awesome week here.

This was my fifth consecutive KScope and I plan to go every year. That is one awesome konference for developers and it just gets better every year. I'll be at KScope15 in Florida for sure! I had a great (more...)

MEMBER OF comparison of PL/SQL and SQL

In the Kscope14 sunday symposium today, Steven Feuerstein explained that MEMBER OF syntax was slow in SQL and fast in PL/SQL. I challenged him that perhaps it was missing indexes on the nested table? My mistake - I got the task of testing it and see if that was the case... So I tested and was surprised at the answer.

I'm creating a nested table type and a table with a column of that type (more...)

Nice evening in Nieuwegein

Thursday I went for a quick trip to Nieuwegein for the Amis KScope Preview. Nice evening :-)

After a train to Copenhagen and a plane to Amsterdam, I checked in at the CitizenM hotel at Shiphol airport. A bit different hotel - toilet and shower in big glass tubes in the room - but actually fairly nice for a single traveller.

Patrick Barel was kind enough to pick me up, so getting to the Amis (more...)

Mini-KScope in Nieuwegein

Can't wait until KScope14 in Seattle?

Or can't make it to Seattle?

Then you can see some of the presentations at a preview at the AMIS offices in Nieuwegein, where some of the KScope14 presenters will try out their presentations in Database development, APEX and ADF tracks. I've been invited to do my presentation on analytic functions, so I'll be there ;-)

It'll be Thursday June 12th 2014. See the agenda here and more details (more...)

See you all in Seattle

In June 2014 I hope to see a whole lot of you at ODTUG's awesome conference Kscope14...

You will not regret going to Kscope14. There is a ton of great content and loads of awesome brainpower to pick ;-) And if you can find the time for it in (more...)

SQL Book Club – Any recommendations?

I got a note from Steven Feuerstein the other day about a group of developers in Stockholm starting an SQL Book Club. What a great idea :-) Anyway, they had asked Steven if he had any recommendations for good books on Advanced SQL. And Steven asked me the same question...


Top selling items – revisited in 12c

April last year I blogged about TOP-N reporting using Top selling items as example. In Oracle 12c we now have a new FETCH FIRST syntax, so in this post I'll revisit the Top selling items example showing where and how FETCH FIRST can be used and where you still need (more...)

Active Data Guard and Invalidations

To provide data source for our datawarehouse (in a seperate MS SQL database, god help it, but that's beside the point :-), we have a setup where we have several views where the datawarehouse connection user has been granted select rights.

When we got Active Data Guard in the spring, (more...)

Half-day masterclass on Analytic Functions (I hope :-)

I've presented on Analytic Functions twice now - at ODTUG KScope12 and UKOUG 2012. Both times I've felt that an hour is not nearly enough to both teach how to use analytics as well as show use cases of how analytics can really be used for solving a lot of (more...)

What I’m doing end of June 2013

It is that time again...

Time to go mingle with the best of the best, learn much, teach what I can, suffer information overload, have fun, enjoy life, and much much more...

In short - time for ODTUG KScope13 \o/ \o/

Hotel and flight has been booked half a year (more...)

PL/SQL Challenge Authorship

The PL/SQL Challenge site by Steven Feuerstein is great for learning various SQL and PL/SQL techniques. I am one of the quiz authors - I write most of the SQL quizzes (and one or two PL/SQL quizzes now and then.)

That means there is now accumulated quite a bit of my work as quizzes - each quiz demonstrating some knowledge of SQL. I could replicate this work as blog posts as well, but instead it is now possible for you to search all my quizzes on PL/SQL Challenge.

I have added that link to the right-hand menu of the (more...)

ROWS versus default RANGE in analytic window clause

I have talked at KScope about the difference between ROWS and RANGE in the analytic window clause, but haven't yet blogged about it. Recently while working out a quiz for the PL/SQL Challenge I discovered yet another reason for remembering to primarily use ROWS and only use RANGE when the actual problem requires it.

From my KScope presentation examples here is a simple case of a rolling sum of salaries:

select deptno
, ename
, sal
, sum(sal) over (
partition by deptno
order by sal
) sum_sal
from scott.emp
order by deptno
, sal

    DEPTNO ENAME             SAL     (more...)

The KScope Charitable Dinner Raffle

Do you want a chance for a dinner with me at KScope13 in New Orleans chatting about SQL? And at the same time get a warm charitable feeling inside helping the volunteers rebuilding New Orleans?

If yes, then read on :-) ...

In January ODTUG started a little competition where you could win a dinner for two at KScope13 in New Orleans by telling about your favorite experience from KScope. I entered a little story from KScope12 where I presented on analytic functions.

Surprise, surprise - I won \o/ ... But as I haven't spotted any other entries in the competition, I (more...)

Recursive subquery graph traversing

In December a user Silpa asked a question on AskTom on "Bi-directional hierarchical query," which inspired me to fool around with recursive subquery factoring (available from version 11.2) giving Silpa a solution which he seemed to find useful. Since then I've fooled around a little more with it, particularly concerning cycles in the graph data.

Silpa gave a table like this for testing:

create table network_table (
origin number
, destination number

And some data as well:

insert into network_table values (11, 12)
insert into network_table values (12, 13)
insert into network_table values (14, 11)

I’m evaluated…

UKOUG 2012 evaluations have arrived - I think I did OK :-).

On a scale from 1 to 6 my scores were:

  • Topic: 5.5
  • Content: 5.5
  • Presentation skills: 4.83
  • Quality of slides: 5
  • Value of presentation: 5.67
I'm quite happy with those scores - particularly that the 6 people that filled out evaluation schemas thought they got a lot of value from the presentation. The skills score is fair, I had expected a bit less as I know I am not world class presenter - but I hope practice makes better :-)

The comments also makes (more...)

Formspider comes to Denmark

For the Danish Oracle User Group (DOUG) I'll be hosting a Formspider event in Copenhagen January 21st 2013. I look forward to seeing Yalim Gerger demonstrate this alternative to APEX or ADF or Forms.

The event will take place in my company's classroom at Banestrøget 17, 2. th., 2630 Tåstrup, which is 2 minutes walk from Høje Tåstrup train station.

Program for the afternoon:
  • 13:30 - 14:30 Introducing Formspider, the Web 2.0 framework for PL/SQL developers
Yalim Gerger, Founder&CEO of Formspider talks about the vision and the benefits of the Formspider Framework.

Thank you, UKOUG 2012

So, I'm about to leave UKOUG 2012. I had a good time and learned quite a bit from the smart people gathered in Birmingham ;-)

Thank you to those attending my presentation on analytic functions - I hope you learned something from it. If you need to take a closer look, both presentation and scripts can be found here.

Birmingham Airport next stop...

Analytic FIFO multiplied – part 3

This is part 3 of a three part posting on analytic FIFO picking of multiple orders. Part 3 shows how to combine the FIFO developed in part 1 with the analytics used for the better route calculation in an earlier blog post.

We use the same tables and same data as part 1, so read part 1 for the setup.

When combining the FIFO for multiple orders with the route calculation, we get this nice piece of sql:

with orderlines as (
select o.ordno
, o.item
, o.qty
, nvl(sum(o.qty) over (
partition by o. (more...)

Analytic FIFO multiplied – part 2

This is part 2 of a three part posting on analytic FIFO picking of multiple orders. Part 2 shows an alternative way of doing the same thing as part 1 did - but this time using recursive subquery factoring in Oracle v. 11.2.

We use the same tables and same data as part 1, so read part 1 for the setup.

And just to recap - here's the picking list developed in part 1:

with orderlines as (
select o.ordno
, o.item
, o.qty
, nvl(sum(o.qty) over (
partition by o.item
order by o. (more...)

Analytic FIFO multiplied – part 1

I have blogged before about Analytic FIFO picking as well as talked about it at KScope12 and will do again at UKOUG2012.

A few days ago Monty Latiolais, the president of ODTUG, had a need to do this - not just for one order which he already had developed the technique for, but for multiple orders, where the FIFO picking for the second order should not consider the inventory that was already allocated to the first order, and so on.

So here is a three-part demo of how to do this.

First we setup the same inventory as (more...)