* Posts by David Harper 1

180 posts • joined 12 Jun 2009


Oracle finally responds to wage discrimination claims… by suing US Department of Labor

David Harper 1

Re: Ok...ok...

I'm reminded of the proverb: Better to remain silent and be thought a fool, than to speak and remove all doubt.

In Rust We Trust: Stob gets behind the latest language craze

David Harper 1

I tried IntelliJ a few years ago, after using Eclipse for a long time. Immediately after running it for the first time, I discovered that it had taken a half-gigabyte crap into a hidden directory. That's not a friendly thing to do, especially in an NFS home directory with quotas enabled. I still use Eclipse.

Virgin Media promises speeds of 1Gpbs to 15 million homes – all without full fibre

David Harper 1

Mine is also allegedly 70, but it drops to half that (or less) every evening and most of the weekend. I know, because I monitor it.

Hell hath no fury like a radar engineer scorned

David Harper 1

Re: And was it a deliberate pun?

And he had the good taste not to stoop to the old "full of seamen" joke.

PowerPoint to start telling you that your presentation is bad and you should feel bad

David Harper 1

I'm slightly disappointed ...

... that nobody has yet mentioned the classic Dilbert "Powerpoint Poisoning" cartoon from 2000:


It's 50 years to the day since Apollo 10 blasted off: America's lunar landing 'dress rehearsal'

David Harper 1

Re: Grit

Many of the astronauts *were* test pilots, as anyone who has watched the film "The Right Stuff" will know.

Your FREE end-of-the-world guide: What happens when a sun like ours runs out of fuel

David Harper 1

Re: It's worse than you think

Answers own question:

Existence of collisional trajectories of Mercury, Mars and Venus with the Earth

Laskar, J. & Gastineau, M. (2009)

Nature, 459, pages 817–819 (11 June 2009)


Jacques Laskar is the real thing when it comes to Solar System dynamics. This paper reports numerical simulations of the orbits of the planets over 5 billion years. In around 1% of them, the eccentricity of Mercury's orbit is pumped up by secular resonances, leading to scenarios where it plunges into the Sun or collides with Venus. In one scenario, the orbits of all four inner planets are de-stabilised, with catastrophic consequences.

Don't have nightmares :-)

David Harper 1

Re: It's worse than you think

"This would be true in a stable system, but there is a good chance that Mercury will eventually be out of its orbit and roaming elsewhere by that point."

Reference to peer-reviewed paper in a reputable journal, please?

David Harper 1

Re: Tidal forces?

The force of gravity grows stronger, the closer you approach a massive object such a a star or gas giant like Jupiter. Now consider a planet or moon orbiting such a massive central body. There's a critical distance, known as the Roche Limit, where the difference between the force of gravity on the star/planet-facing side is so much greater than the force of gravity on the side furthest from the star/planet that it tears the orbiting body apart. This is a likely scenario for how Saturn's rings were formed: a small satellite's orbit took it so close to Saturn that the differential gravitational forces ripped it apart. It's also the fate that awaits Phobos and Deimos, the moons of Mars, which are slowly spiralling in towards the planet.

David Harper 1

Re: Tidal forces?

Not so. The orbiting bodies raise tides on the central body. Energy and angular momentum are exchanged. The orbits change. This is why the Moon is slowly drifting away from the Earth and the Earth's rate of rotation is decreasing. That in turn leads to the need for leap seconds, and hey presto, it becomes an IT problem :-)

David Harper 1

It's worse than you think

The Sun's luminosity and surface temperature are increasing by about 10% every billion years, so in a couple of billion years time, the Earth's surface will be too hot to sustain liquid water. Game over. And in five billion years, when the Sun runs out of hydrogen and turns into a red giant, there's an even chance that it will swallow the Earth as it expands. Mercury and Venus are definitely doomed to this fate, and the Earth may also end up inside the Sun.

But on a truly astronomical timescale, on the order of 10**38 years, all baryonic matter will vanish as protons decay into muons and electrons. Then we're *really* stuffed. (Reference: "A Dying Universe", F.C. Adams and G. Laughlin, 1997, Reviews of Modern Physics, Vol. 69, pp 337-372)

Motion detectors: say hello, wave goodbye and… flushhhhhh

David Harper 1

Why it's important to specify units.

A 37-degree rectal jet wash would be okay in Europe, but they use Fahrenheit in America, and that's barely above freezing point.

Want to learn about lithium-ion batteries? An AI has written a tedious book on the subject

David Harper 1

IBM did this thirty years ago

Back in the 1980s, a popular joke among IBM mainframe users was that the system manuals had been written by humans but then passed repeatedly through an algorithm designed to remove all trace of personality or style before being printed.

Stop us if you've heard this one: IBM sued after axing older staff, this time over 'denying' them their legal rights

David Harper 1

Re: When I was a wee lad

A wise colleague once told me: Always remember that HR is not on your side. Their job is to implement management decisions.

Champagne corks undocked as SpaceX brings the Crew Dragon back to Earth

David Harper 1

Re: Well done, SpaceX ...

According to NASA data, from Gemini 8 onwards -- and including every single manned Apollo flight -- no spacecraft splashed down more than ten miles from the target. I'd call that pretty accurate in the pre-GPS era.

David Harper 1

Well done, SpaceX ...

... for successfully repeating what NASA already did fifty years ago, but with 1960s technology.

WWW = Woeful, er, winternet wendering? CERN browser rebuilt after 30 years barely recognizes modern web

David Harper 1

Re: Not by hand

"Almost any word processor is preferable to Tex/Latex."

I'm guessing you don't write anything that contains mathematical equations, which is where TeX and LaTeX excel. (Pun very definitely intended.)

David Harper 1

Re: And the content has not improved since then.

Your limestone inscriptions won't survive acid rain. Baked clay tablets are the real long-term solution. Ancient Babylonian web pages are still readable after more than 2000 years. Now, where's my cuneiform-to-English dictionary ...

DNAaaahahaha: Twins' 23andMe, Ancestry, etc genetic tests vary wildly, surprising no one

David Harper 1


You're basically saying that every Ancestry/23andMe-type DNA analysis based on the product of PCR amplification is so full of errors introduced by the PCR process itself as to be useless. It's worth noting that the study which you cited by Zhou, Zhang and Ebright is from 1991, and focusses on a specific polymerase. The science of DNA-wrangling has moved on a LONG way since 1991.

Come mobile users, gather round and learn how to add up

David Harper 1

I hope the mobile network wasn't 3

Advertising 2+2=4 on the 3 network's web site would be a bit awkward :-)

Tape vendors feel the cold, clammy hand of AWS on their shoulders. Behind them grins the Glacier Deep Archive

David Harper 1

Re: Retrieval time

"the amount of time it takes isn't as important"

I'm guessing you've never had a pointy-haired boss screaming at you when someone accidentally dropped the company's mission-critical database, and you're the DBA who has to get the whole thing up and running again from the backup tape. Retrieval time seems pretty fscking important then :-)

What now, Larry? AWS boss insists Amazon will have dumped Oracle database by end of 2019

David Harper 1

Re: In Ten Years Oracle Will Be Wanged...

"we'll rip out that RDBMS, put in a nosql layer"

Because everyone knows that MongoDB is webscale.


David Harper 1

That's just not true

Everyone expected Oracle to kill off MySQL when it bought out Sun Microsystems ten years ago. I'm no fan of Oracle, but I will give them credit for this - they have invested money and people in keeping MySQL alive and improving it. They cleaned a lot of the cruft out of the source code they inherited ten years ago, then added a string of new features, which they gave away for free in the community edition. They are still adding neat new features. MySQL 8 is a huge step forward from MySQL 5.7.

The two main forks of MySQL, MariaDB and Percona Server, are both based on the Oracle source code, so even MySQL veterans like Monty Widenius and the folks at Percona recognise that Oracle has added value to MySQL.

And if you want to complain that Oracle keeps the super-useful features for the paid-for enterprise version of MySQL, I'd just point out that Percona and MariaDB do the same thing.

Behold, the world's most popular programming language – and it is...wait, er, YAML?!?

David Harper 1

The ghost of John Backus would like a quiet word

"Any language where the amount and flavour of whitespace is significant should be strangled at birth."

Except FORTRAN, of course.

Junior dev decides to clear space for brewing boss, doesn't know what 'LDF' is, sooo...

David Harper 1

It's not ancillary, it's a critical part of the database

The transaction log file is NOT an "ancillary" part of the database. It's a critical file, which is just as important as the data files, since the state of the database is represented by the combination of data files AND transaction log file. The transaction log file contains changes to the data that have been committed, but that may not have been applied to the data files yet.

GCSE computer science should be exam only, says Ofqual

David Harper 1

Practical programming exams? I was doing that 25 years ago.

Back in the early 1990s, I was teaching a graduate-level programming course at one of the colleges of the University of London. The end-of-course assessment was a set of programming exercises that the students completed under exam conditions on PCs running MS-DOS. They copied their work onto a 3.5-inch floppy that I gave them at the end of the exam. I allowed them to consult their printed course notes during the exam, so it wasn't purely a test of memory, and this was before the Interwebs, so they couldn't google the answers.

Has science gone too far? Now boffins dream of shining gigantic laser pointer into space to get aliens' attention

David Harper 1

Reminiscent of Liu Cixin's "The Three-Body Problem"

Liu Cixin's science fiction trilogy "The Three-Body Problem" was mentioned earlier. This starts out with humans signalling their existence via an amplified radio signal. It's a superbly-written series of novels.

British Airways: If you're feeling left out of our 380,000 passenger hack, then you may be one of another 185,000 victims

David Harper 1

Re: Close call?

It was malicious code in a third-party JavaScript library. The most likely explanation is careless web developers at BA's outsourced IT division who used the third-party libraries in the first place. Never attribute to malice what can be adequately explained by incompetence.

Unexpected MySQL database meltdown fingered in GitHub's 24-hour website wobble

David Harper 1

No MySQL replication slaves for failover?

Any competent DBA will tell you that you should be running multiple replication slaves of any mission-critical MySQL database server, and they should be using different back-end storage systems than the master. These replication slaves can provide read-only copies for load-balancing, and can also be promoted to become a read/write master in the event that the master suffers a hardware failure.

Someone at GitHub/Microsoft evidently didn't get beyond chapter 1 of the "How to be a production MySQL DBA" notes.

New theory: The space alien origins of vital bio-blueprints for dinosaurs. And cats. And humans. And everything else

David Harper 1

Re: Assumption: There is a god and he* created everything.

"Quite some manners, that. Dude needs a mom, I'd say."

Or a supply of socks.

First Boeing 777 (aged 24) makes its last flight – to a museum

David Harper 1

Re: Still have the book

The wing deformation test on the first prototype was both spectacular and reassuring. They clamped the undercarriage down, then put a hydraulic jack under one wing tip. The wing was at around 45 degrees to the horizontal before it finally failed.

It was also reassuring to know that the 777 could fly for a couple of hours on a single engine, especially when my wife and I were on a Chicago to London flight that was suddenly diverted to Bangor, Maine after the captain had to shut down one engine. Having seen the documentary, we weren't in the least worried about making a safe landing.

Automated payment machines do NOT work the same all over the world – as I found out

David Harper 1

Just what I needed on a Friday afternoon

Hats off to Mr Dabbs for "I miei capezzoli esplodono di gioia.". I copied it into Google Translate, and my monitor now has a fine coating of coffee all over it.

Brit ISPs get their marker pens out: Speed advertising's about to change

David Harper 1

Re: Hmmm...

That's definitely NOT my experience. Like you, I pay Virgin Media for what they call their 70 MB/s tier. I have a cron script on a Linux box which measures my download speed every hour, and whilst the speed is indeed close to 70 in the wee small hours of the morning, it drops below 40 between 4 p.m. and 11 p.m. most evenings, and sometimes it's as low as 20. I've managed to get a refund on my monthly bills a few times after posting graphs of the download speed to the Virgin community forum, but not recently. I guess they don't give a sh*t any more.

Astroboffins spy the most greedy black hole yet gobbling a Sun a day

David Harper 1

Proper units, please

"It has a voracious appetite and gobbles a mass equivalent to twice that of our Sun every two days to sustain itself."

That's 12 milliJupiters per second, just to put things in proper perspective.

Australian prisoner-tracking system brought down by 3PAR defects

David Harper 1

Well thanks a lot

I won't be able to see NSFW now without think it stands for New South F***ing Wales.

Take-off crash 'n' burn didn't kill the Concorde, it was just too bloody expensive to maintain

David Harper 1

Watch the Channel 5 documentary

Channel 5 showed a two-part documentary late last year which included interviews with some of the aviation engineers who were involved in developing Concorde and solving the many technological challenges. It's well worth watching and it highlights what an engineering marvel Concorde was.

The Imperial War Museum at Duxford has the Concorde which was used for testing in extreme conditions. You can walk through the interior. The front half is fitted with seats to show what passengers would have experienced, whilst the back half still has all of the test and monitoring equipment in place.

Windrush immigration papers scandal is a big fat GDPR fail for UK.gov

David Harper 1

Re: History will be history!

Indeed. The government retains census records going back to 1841, and makes them publicly (and now digitally) available once they are more than 100 years old. What were once records collected to allow government to monitor the population are now a priceless resource for historians and genealogists.

The Agile and the Continuous: Database Drift ... Neat film title but something to avoid

David Harper 1

Crossing the Fence 2

Like Bill M, I've been on both sides of the fence, as well as straddling it for a while when I managed a cluster of MySQL databases for my development team before the in-house 100%-Oracle DBA team would admit that MySQL was actually a database system.

During my developer days, I worked alongside some bright young things who were evangelising Ruby-on-Rails. According to them, ActiveRecord was the dog's bollocks. You never had to write a line of SQL, and it automatically ensured the referential integrity of the database without the need for anything as 1970s as foreign key constraints. Imagine their surprise when the production database started to show inconsistencies such as phantom relationships and missing entities. When I was asked to add foreign key constraints, I ran a consistency check on the existing data and found a huge mess. I left the team to become a DBA soon afterwards.

'Your computer has a virus' cold call con artists on the rise – Microsoft

David Harper 1

Re: Re "putting the phone down is almost always the right thing to do."

My wife regards this as an excellent sport, and she will happily spend 20 minutes playing along. My preferred approach involves making anatomically impossible suggestions, which generally results in a far shorter call.

Creaky NHS digital infrastructure risks holding back gene boffinry, say MPs

David Harper 1

Re: 200GB to store a genome? Surely not!

No, this is just plain DNA sequencing data, which is strings of A, C, G and T.

David Harper 1

200GB to store a genome? Surely not!

A human genome is 3.2 billion base pairs, and each base pair can be represented as a single letter from the set {A, C, G, T} so even if you use (a wasteful) one byte per base, that's still only 3.2 GB. If you encode a base in the most efficient way, as two bits, you can reduce the size to 800 MB. So where does 200GB come from?

(I work in bioinformatics and I've written large-scale applications that store entire genomes, so I have a bit of experience in this field.)

Cloudflare touts privacy-friendly public DNS service. Hmm, let's take a closer look at that

David Harper 1


You might want to read RFC 1918, specifically Section 3, which defines the three blocks of IP addresses that should be used for private/internal networks:

"3. Private Address Space

The Internet Assigned Numbers Authority (IANA) has reserved the

following three blocks of the IP address space for private internets: - (10/8 prefix) - (172.16/12 prefix) - (192.168/16 prefix)"

Developer recovered deleted data with his face – his Poker face

David Harper 1

The game was much more entertaining if you tweaked the parameters that set the strength of gravity and the wind speed. Hurling bananas into a hurricane in Moon gravity was fun.

Astro-boffinry world rocked to its very core: Shock as Andromeda found to be not much bigger than Milky Way

David Harper 1

Galaxy of restricted growth, if you don't mind.

It knows where the gravel pits and power lines are. So, Ordnance Survey, where should UK's driverless cars go?

David Harper 1

Re: Maps are useful, but things change

"Google shows the new Harwell Village bypass (the little road to the east of the A34), OS doesn't. The road isn't even open yet... yet Google already includes it."

You'd better hope that satnav systems are using the OS version, then, otherwise the workers building the bypass will get a nasty surprise when some clueless idiot follows his satnav's instructions to take the road that they are still building.

Virgin Media skulks in disused public toilets

David Harper 1

"Rather ironically, one of Bazalgette's descendants now runs a TV production company. One could easily draw parallels between that, the internet and the industrialised movement of civilisation's waste."

It's a VERY old joke: Joseph Bazalgette made a fortune pumping shit out of people's homes. His great-great-grandson made his by reversing the flow.

ICO probes universities accused of using private data to target donation campaigns

David Harper 1

This is nothing new.

This is nothing new. I was called at home one evening about 25 years ago by a student fundraiser from my alma mater, one of the colleges of the University of London. He started his begging pitch by asking if I knew how little money university lecturers were paid. I told him I did, since I was a lecturer at one of the other colleges of the University of London at the time. Needless to say, the call didn't go on much longer.

'Sticky runway' closes Canadian airport

David Harper 1

For those of you unfamiliar with the joke:


ICANN gives domain souks permission to tell it the answer to Whois privacy law debacle

David Harper 1

What's the problem?

I own a number of domains in .com, .co.uk and .eu, and my registrar hides my personal contact information for all of them.

Indeed, my registrar's default position for all new domain registrations is to hide the owner's contact details, replacing them with a forwarding postal address and an email address which forwards to my private email but which changes every few days to foil spammers. They can harvest the address, but in ten days time, it will no longer be valid.



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