Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror

Comment Re:Color me skeptical. (Score 1) 213

The thing that determines how much work the database has to do in order to produce the results is the FROM, the WHERE and the GROUP BY, because those are the ones that determine what's going to be accessed, joined, sorted and how. The SELECT (except for the use of aggregate functions) primarily just decides what information to present from the join results and how to present it.

I don't think this is correct. The SELECT list does impact the performance of the query because if it requires un-indexed columns that are not used any other clause(WHERE, FROM) than a lookup or a table scan will be needed to retrieve the values. This being said the only way that removing a column form the select list of a query will make it slower is if the query planner has some bugs :)

Comment Most people are not bothered (Score 3, Informative) 197

Most people in the UK are happy to be profiled in exchange for financial benefits. When the Tesco Clubcard was introduced it was so popular that people stopped shopping at other supermarkets like Sainsburys, which then had to introduce their own "loyalty card" schemes. Tesco announced last year that there are now 16 million active clubcards in the UK. As a comparison point there are around 25 million households in the UK , so a significant number of British households are having their shopping profiled in detail already.

Comment Re:Thermodynamics (Score 1) 187

I dont get why you guys are discussing the possiblity of a hydrogen burn/explosion. This would only happen if the hydrogen is stored, and then only if it gets stored in large amounts. At the infinitessimal amounts that appears to be released during this process, it makes no sense to even try to store it beyond what makes for an efficient amount to bother igniting it. Storing hydrogen is impractical at best, and as hydrogen has the smallest possible atomic structure, it can pretty much escape any container, so noone stores hydrogen beyond what they need for immediate use anyway.
So obviously, the hydrogen needs to be used (almost) immediately, and very little if any amount stored. Presumably it would be burned to produce electricity for lights, or during winter for heating the highways, Both of which would produce safer, greener highways. Or during summer and daylight, being transmitted directly into the electric grid, similar to power from water/windmills, wavemachines or solar cells.

Comment Re:You're right (Score 1) 601

I guess I fall under the category of "liberal," although I think in just about any other developed democracy I'd be far closer to the center. And I watch FOX news from time to time, but only in the sense of being fascinated by the train wreck. Maybe there are other liberals who watch for other reasons, but I suspect that is the common one.

Comment Re:sweet (Score 1) 335

Regardless of cost, you might not even be able to get business cable unless a lot has changed at Comcast. I had Comcast as a provider in northern Florida several years ago. I wanted to run my own mail and web servers and I was willing to pay the premium for "business" service to get static IPs. One would think that if I had consumer cable internet from them I would be able to upgrade that to business cable. Not so. After several hours being switched from one call center to another it was "determined" that business cable was not available in my area.

Again, this was several years ago and the situation may be different now.

Comment Re:infernal machines (Score 1) 419

I see this comparison all the time when talking about the effects of the bomb. It almost seems like the bomb saved lives. It did not. The effect was 200K dead (+-). The alternative to that was not invading Japan (and millions of casualties) but not invading Japan and negotiating peace - that was the rational way out. The dead were caused by America's lack of willingness to accept anything less then unconditional surrender.

Comment Re:But... (Score 1) 553

You are a surprising idiot. The way it works here (Europe) and the way the laws are probably on your side is this: when you come to a pedestrian crossing you slow down to a speed that allows you to stop the car should someone walk "into traffic". For all intents and purposes pedestrians have the right to cross first. If the visibility is so poor than you just stop the car and cross when you're confident. Otherwise if you kill/maim someone than you go to jail.

Slashdot Top Deals

Repel them. Repel them. Induce them to relinquish the spheroid. - Indiana University fans' chant for their perennially bad football team

Working...