After their comprehensive defeat at Lord’s back in June, some experts were confidently predicting that Australia would be on the wrong-end of a clean sweep in both of the back-to-back Ashes series.
Mitchell Johnson, if he was mentioned at all, was written off by all and sundry. After all, not only did he not hand homework in on time, he couldn’t be relied upon to hit a barn door, let alone a set of stumps.
Fast-forward a few months and you can see that conventional wisdom has held…to the extent that no barn doors have been dented.
Unfortunately, the same cannot be said of English pride.
Mitch and his mates have a bit of time on their hands before Australia visit South Africa next month – that nice Mr Lehman has let the class off homework – so they’re free to assist in contradicting another of those things that “everyone knows” – SQL is always faster than PL/SQL.
What we’re going to cover here (among other things) is :
a quick overview of the LOG ERRORS mechanism (Mitch doesn’t do any other speed)
a recap of the older PL/SQL SAVE EXCEPTIONS
performance comparison between the two with errors present
Explore the limits of LIMIT
performance comparison when no errors are present
Mitch is standing at the top of his run. A random English batsmen is quaking at the crease, so let’s get started… Continue reading →
Early evening TV in our house is Soap time. Deb annexes the remote control, after which we are treated to an
assortment of angry women being angry with each other in a variety of accents originating from the North of England.
It could be worse, I suppose. We could be subjected to the offering on the other main channel ( angry London women being angry at each other in accents originating from the South East of England).
Then again, either is preferrable to an angry Welsh woman being angry at you in a Welsh accent.
Ok then, how do you make a database professional hot under the collar ? Mention the EAV design pattern.
This pattern goes by many names, most commonly :
EAV – Entity-Attribute-Value
OTLT – One True Lookup Table
Diabolically Enticing Method Of Data Storage (DEMONS)
OK. I made that last one up.
It is with some trepidation ( and having donned precautionary flame-proof underpants) that I am embarking on an exploration on the nature of EAV and whether it can ever be appropriate for use in a Database. Before we go any further though, I’d like to take a moment to clarify exactly what the term “database” means in the context of this discussion Continue reading →
A wise man once said that those who fail to learn the lessons of history are doomed to repeat them.
Time for a quick history lesson…
England’s recent supremacy in Ashes contests have a commmon theme running through them. In none of the last three series has any Australian fast bowler sport any facial hair.
The bristling tache has been a feature of potent Australian attacks since time immemorial.
From Frederick “The Demon” Spofforth sporting the face furniture that inspired an England batting collapse which gave birth to the Ashes legend, through Dennis Lillee and (occasionally) Jeff Thompson, the tache reigned supreme.
Having reached an exuberant zenith whilst working with Merv Hughes, the tache took a lower profile for a time as the top-half of Jason Gillespie’s beard.
There was a time during the 80’s when England seemed to have cottoned on to the power of the tache and managed to fight fire with fire with notable contributions evident on the upper lips of Botham, Gooch and Lamb.
More recently however, the moustache’s mystic ability to make an English batting line-up do a passable impression of a deck-chair seemed to have been lost in the mists of time.
Then along came Mitchell Johnson’s Movember Mush Mantle.
Johnson himself has quite a respectable test record, but it seems that he may have re-discovered the secret power of the mighty moustache.
As we’ve got a couple of weeks before the second test begins, the moustache has a bit of time on it’s handlebars so has kindly agreed to illustrate the fun and games to be had with assigning default values to PL/SQL parameters. Continue reading →
I’ve been seeing rather a lot of Chris Hemsworth lately…in more ways than one.
My most recent trip to the local Cinema saw him reprising the role of Thor, or “Phwoarrr !” as Deb insists on calling him.
No spoilers, but let’s just say that the scene with the topless blonde was not all I’d hoped for.
Not that I feel the need to compete but, like Chris, I can also do my bit to save the planet, courtesy of a bit of recycling.
Once upon a time, when you issued a DROP TABLE command, the table, together with it’s associated indexes and triggers, was wiped from the face of your database, as if it had never existed.
Of course, if you subsequently decided that you shouldn’t have dropped the table, your options were limited to re-creating it (and the data, indexes etc) by hand, or going through the fun and frolics of a point-in-time recovery.
Since 10g however, things have been a bit different. Continue reading →
Following the trend in these straightened times, Deb and I decided to stay at home this year rather than going away on holiday.
I say “decided”, but this was really more due to the fact we were terribly grown up and bought a house last year.
As a result, the only recreation we could afford was a walk around the garden…whilst pushing a lawn-mower.
In an attempt to recall happier times, I’ve had a look back of some of the photos from our last proper holiday, in Canada.
As well as providing some happy memories, this also gives me the opportunity to explore how to compare an operating system file ( such as a jpeg) with a LOB held in the database. Continue reading →
Space. The Final Frontier.
My long-suffering Mrs does enjoy a bit of sci-fi especially if some hunky all-action type is wandering around with his shirt off.
“That man has such a nice personality”, she may well sigh, staring dreamily at the screen.
As with any software Oracle error messages can look as if they’ve been put together in some alien language.
This is especially true if your fairly new to Oracle.
When you get space errors in Oracle, the answer is not necessarily to simply add more space.
What we’re going to look at here is :
what a tablespace is and the various things they are used for
how redo logs work ( and how they are archived)
some of the space related errors you may encounter and what the underlying causes may be
Of necessity, I’ve made some generalisations here. The purpose of this post is not to provide an in-depth technical guide to the inner workings of Oracle. Rather it is to provide enough information for you to work out whether you should be looking up the phone number for your hard-pressed DBA, or looking at that bit of code you’ve just run.
Also, like the author, this post is a bit short of cache. For the sake of simplicity (and that weak pun), I’m going to pretend that Oracle uses memory in one amorphous lump.
Additionally, I’ve not taken into consideration Direct Path Inserts.
Steve McNulty. Even the name sounds a bit hard. This is not the hero in Jason Statham’s latest celluloid exploit. Neither is it the central character in a hard-bitten cop drama.
Steve McNulty is, in fact the current Luton Town captain and a member of an endangered species – the stopper Centre-Half.
When you first set eyes on him, he looks, well, a bit chunky. You might imagine his nickname to be “Big Mac” because of his penchant for a certain fast-food chain.
This is something of a mis-conception.
Firstly, he’s not overweight. In contrast to the other players on the pitch, his body has not so much been honed to athletic perfection as hewn from solid rock.
It is a build that has not been seen for years in the elite (effete ?) Premier League.
He’s not the fastest player, as you’d expect, but he’s strong in the tackle. When he heads the ball, adjectives such as cushioning and glancing do not apply. It’s a Kirby Kiss (he’s a Scouser). The ball is definitely not his friend.
So, Big Mac he is not. He couldn’t be associated with anything that’s served with namby-pamby french-fries. A McNulty burger is a huge slab of meat wedged between two halves of a cottage loaf. It would only ever be served with chunky chips.
It’s McNulty and friends that provide the inspiration for the examples that follow.
I recently came across a situation where I needed to take some relational data and convert it into a hierarchy for the purposes of dropping it into an APEX tree. This proved slightly more challenging than I originally thought. Continue reading →
Recently, Deb got tickets for us to go to an outdoor cinema.
“It’ll be lovely”, she said, “we can have a picnic on a warm summer’s evening whilst watching a film”.
“Sounds good”, I said, trying hard to overlook the fact that, in England, a summer’s evening is as likely to be wet as it is to be warm.
Fortunately the weather held, the picnic was delicious and the company, needless to say, was divine.
As for the film…”I can’t believe that you’ve never seen Mama Mia before”, exclaimed my better half.
Some intensive negotiations followed on the subject of Brownie Points. As a result, my late Saturday evenings for the next three months will definitely include watching Match of the Day. Yes, I will get to watch A Man After Midnight. Continue reading →
Dynamic. That’s a positive word if ever there was one. Ascribing this adjective to anything would convey an image of energy and forward momentum.
On the question of Dynamic SQL, the images are rather more equivocal.
On the plus side, Native Dynamic SQL gives you the ability to :
execute DDL statements from within PL/SQL programs
code for instances where the required DML statement is not known ahead of time
On the flip side, it can also mean code that is:
difficult to read and maintain
prone to performance problems
To wander through this minefield, I have enlisted the support of a world where DRS does not stand for Dodgy Review System.
Yes, it’s the wacky and entertaining (not always intentionally so) world of Formula 1… Continue reading →
It is a strange time in the UK.
I’m not referring to England being 2-0 up after 2 tests in the Ashes (something that happens about as often as a Briton winnng the Men’s Singles at Wimbledon), nor the fact that a Briton has won the Tour de France for the second year running.
Stranger even than that is the bright yellow ball in the sky which has replaced the traditional warm rain of the British Summer.
This phenomenon has had a strange effect on the cat. Her animal instincts obviously alerted by the unfamiliar change in the climate, she currently spends almost all of her time out in the garden.
Unfortunately, she seems to have decided to treat said garden as something of a litter tray. This will necessitate something of a mine-sweeping exercise before I next mow the lawn.
It’s frustrating when you’re anxious to start something but then hit an unpleasant roadblock.
For example, you may have decided to have a play with that Oracle XE/Apex installation on your laptop that you haven’t used for a little while. However, when you come to connect, you realise that you can’t remember the password.
Health Warning – Before I go any further, I should point out that doing this is not something I’d recommend on anything other than a system that’s being used simply as a playground for you to experiment and which contains no sensitive data.