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)
(more...)

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...)