CREATE USER and ALTER USER – changing passwords and a New Year’s Resolution

Monday morning. The first day back at work in the New Year.
Still groggy, having been awoken from my slumber at the insistence of my Darth Vader Lego Alarm Clock, I stagger downstairs in search of coffee.
The clock was a Christmas present from Deb. Whilst clinking around the kitchen, I wonder whether it was intended as a subtle reminder of how she likes her coffee with only a little milk. Yes, she prefers it on the Dark Side.
Then I remember. I usually avoid New Year’s resolutions. I find them to be not unlike a cheap plastic toy at Christmas – there in the morning and then broken by the first afternoon.
This year however, is an exception.

In a recent post about APEX Authentication Schemes, I went to great lengths to ensure that a dynamic SQL statement to re-set a users password was safe from the possibility of injection.
Fortunately, Jeff Kemp took the time to point out a couple of issues with my approach.
As a result, this year, my resolution is to :
READ THE MANUAL.

What follows is the result of keeping this resolution ( so far, at least)…

Implementing a Database Authentication Scheme in APEX

The following tangential opening was written especially for Scott Wesley in the hope that he’ll be minded to point out any errors in what follows. The same applies to Jeff Kemp ( although I don’t know if he’s into the AFL).
Unlike me, both of these guys are APEX experts.

Football. It’s a term that means different things to different people.
To a European, it’s most likely to be a reference to good old Association Football ( or Soccer).
To an American, it’s more likely to be the Grid-iron game.
A New Zealander will probably immediately think of Rugby Union.
An Australian ? Well, it’s probably a fair bet that they’ll think of Aussie Rules Football.

On the face of it, the rules appear rather arcane to an outsider. 18-a-side teams kicking, catching and punching something that resembles a Rugby ball around a pitch that resembles a cricket oval. Then there is the scoring system.
“Nice Behind”, to an AFL player is more likely to be taken as a compliment of their skill at the game than an appreciation of their anatomy.

Then again, it’s easy to scoff at any sport with which you are unfamiliar.
For example, Rugby could be characterised as 30 people chasing after an egg. Occasionally, they all stop and half of them go into some strange kind of group hug. I wonder if the backs ever get paranoid because they think the forwards are talking about them ?

As for soccer, even afficionados will acknowledge that there’s something a bit odd about a game where 22 millionares spend lots of time chasing after one ball…when they’re not rolling around in apparent agony after appearing to trip over an earth worm. I mean, the ball isn’t that expensive, surely they can afford one each ?

The point of all of this ? Well, what is considered to be obscure, eccentric, or just plain odd often depends on the perspective of the observer.

Take APEX authentication schemes for example.
Whilst not the default, Database Authentication is a scheme that is readily available. However, there doesn’t seem to be much written on this subject.

In contrast, there is a fair bit out there about APEX Custom Authentication. A lot of it would appear to re-enforce the idea that implementing security by hand is fraught with difficulty.
Just one example can be seen here.

If we were to approach this topic from the perspective of looking to migrate an elderly Oracle Forms application – where each user has their own database account – to APEX, we might be attracted to the idea of a Database Authentication Scheme and want to find out more.

What follows is my adventure through setting up such an Authentication Scheme.
Specifically, I’m going to cover :

• Creating an APEX Database Authentication Scheme
• Default behaviour
• Adding a Verification Function to restrict access to a sub-set of Database Users
• The vexed question of password resets

Kilobytes, Kibibytes and DBMS_XPLAN undocumented functions

How many bytes in a Kilobyte ? The answer to this question is pretty obvious…and, apparently, wrong.
Yep, apparently we’ve had it wrong all these years for there are, officially, 1000 bytes in a Kilobyte, not 1024.
Never mind that 1000 is not a factor of 2 and that, unless some earth-shattering breakthrough has happened whilst I wasn’t paying attention, binary is still the fundemental basis of computing.
According to the IEEE, there are 1000 bytes in a kilobyte and we should all get used to talking about a collection of 1024 bytes as a Kibibyte

Can you imagine dropping that into a conversation ? People might look at you in a strange way the first time “Kibibyte” passes your lips. If you then move on and start talking about Yobibytes, they may well conclude that you’re just being silly.

Let’s face it, if you’re going to be like that about things then C++ is actually and object orientated language and the proof is not in the pudding – the proof of the pudding is in the eating.

All of which petulant pedantry brings me on to the point of this particular post – some rather helpful formatting functions that are hidden in, of all places, the DBMS_XPLAN pacakge…

Sayonara to Sequences and Trouble for Triggers – Fun and Games in Oracle 12c

Ah, Nostalgia.
Not only can I remember the Good Old Days, I also remember them being far more fun than they probably were at the time.
Oh yes, and I was much younger….and had hair.
Yes, the Good Old Days, when Oracle introduced PL/SQL database packages, partitioning, and when the sequence became extinct.
Hang on, I don’t remember that last one…

ANSI Joins and Uppercase Keywords – making PL/SQL look less like COBOL

The month-long festival of football has finally come to an end.
A tournament that was supposed to be about “No 10s” and the coronation of the host nation has lived up to expectations. Ironically, by defying them.

Where to start ? Well, it seems that goalkeepers had something to say about just who the star players were going to be.
Ochoa, Navas and Neuer were all outstanding, not to mention Tim Howard. I wonder if he could save me money on my car insurance ?
Those number 10s were also in evidence. However, in the end, it wasn’t Neymar, Messi, or even Mueller who shone brightest in the firmament. That honour belonged to one James Rodriguez, scorer of the best goal, winner of the Golden Boot, and inspiration to a thrilling Columbia side that were a bit unlucky to lose out to Brazil in a gripping Quarter Final.
Now, usually a World Cup finals will throw up the odd one-sided game. One of the smaller teams will end up on the wrong end of a good thrashing.
This tournament was no exception…apart from the fact that it was the holders, Spain, who were on the wrong-end of a 5-1 defeat by the Netherlands.
Then things got really surreal.
Brazil were taken apart by a team wearing a kit that bore more than a passing resemblence to the Queens Park Rangers away strip.
The popular terrace chant “It’s just like watching Brazil” may well require a re-think after Germany’s 7-1 win.
So, Germany (disguised as QPR) advanced to the final to play a side managed by a former Sheffield United winger.
Eventually, German style and attacking verve triumphed.
Through the course of the tournament, O Jogo Bonito seems to have metamorphosed into Das Schöne Spiel.
The stylish Germans are what provide the tenuous link to this post. I have once again been reviewing my SQL and PL/SQL coding style.
What follows is a review of some of the coding conventions I (and I’m sure, many others) have used since time immemorial with a view to presenting PL/SQL in all it’s glory – a mature, powerful, yet modern language rather than something that looks like a legacy from the pre-history of computing.

DBMS_DATAPUMP – why quote delimiters are your friend

So, the World Cup is in full swing.
Now the lesser teams have fallen by the wayside ( England), we can get on with enjoying a feast of footie.
As well as a glut of goals, the current tournament has given us a salutory reminder of the importance of diet for elite athletes.
After predictably (and brilliantly) destroying England single-handedly, Luis Suaraz found himself a bit peckish and nipped out for an Italian. Now the whole world seems to be commenting on his eating habits.
Like Luis, you may find yourself thinking that you’ve bitten off more than you can chew when confronted by DBMS_DATAPUMP.

The documentation does offer some help…to an extent. However, the whole thing can seem a bit fiddly, especially if you’re used to the more traditional command-line interface for Datapump.

What follows is a tour through DBMS_DATAPUMP based on my own (sometimes painful) experience, broken down into bite-sized chunks.
Much of the functionality to filter object types and even data is common to both Exports and Imports.
So, the approach I’ve taken is to cover the Export first, with a view to finally producing a Full Database export.
I’ve then used the Import process against this to demonstrate some of the package’s filtering capabilities.
So, what’s on the menu today ?

• Privileges required to run a DBMS_DATAPUMP job from your current schema and for the whole database
• Running a consistent export
• Running datapump jobs in the background
• Monitoring running jobs
• Importing from one schema to another
• Specifying the types of objects to include in Exports and Imports
• Specifying subsets of data
• DDL only Jobs
• How to Kill a Datapump Job

The full code examples have all been written and tested on Oracle XE 11gR2.
I’ve tried to maximise the use of in-line hard-coded values and minimise the number of variables in an attempt to make the code easier to follow.
Also, in these examples I’ve made use of the default DATA_PUMP_DIR directory object, but you can use any directory object to which you have the appropriate privileges.

For dessert, there are a couple of other DBMS_DATAPUMP features that I have found useful that are specific to Enterprise Edition ( in one case, with the Partitioning Option) ;

• Including specific table partitions
• Parallel processing

So, a fair bit to get through then. I hope you have an apetite…

Putting the Plus into SQL*Plus – describing a Package member (with added kittens)

Deb’s been on about getting another cat recently.
“Absolutely not !”, I said, putting my foot down very firmly.
Oh yes, we all know who wears the trousers in this house thank you very much.
So…Cleo the Kitten is now making herself at home.

In fact, she’s on the desk now, sniffing at the key..$#%3″!Q…make that running across the keyboard.
Obviously, she’s not quite mastered the basics of shell scripting yet ( although she does evidently know that it employs most of the keys on the top row of the keyboard).
Maybe we need to start her off with something a little less complicated.
Not however, the sanctity of those cute and fluffy Oracle IDEs, I’ve had quite enough cute and fluffy for one day.
Instead we’re going to have a look at the grizzled old moggy that is SQL*Plus.

In my defence, I will say that the use of SQL*Plus is a something of a necessity for me as I spend a lot of time on the train and so write much of my ramblings on a small, elderly netbook.
I’ve got XE running on it so firing up an IDE will slow things down considerably.
And yes, OK, I did start programming before the World Wide Web and GUI desktops…but no, not before the invention of the internal combustion engine, Deborah. Honestly, haven’t you got a kitten you should be playing with ?

My starting point is simply this – wouldn’t it be great if you could use the DESCRIBE function to lookup a single member of a package in SQL*Plus.

So, what I’m going to cover here is :

• How to get argument details for package members from the Data Dictionary
• Building a pipelined function ( using a cursor for loop)
• Mimicing the DESCRIBE functionality using SQL*Plus structures and formatting

Right, stop sharpening your claws on that sofa and pay attention…