Follow Slashdot blog updates by subscribing to our blog RSS feed


Forgot your password?

Comment Re:Commercial databases (Score 1) 509

I created new databases and tables to have a fair comparison for performance testing. There were no indexes at all used for testing. That wasn't meant to be a robust test of the capabilities, but more of a validation of what was happening and why. I agree that with the right architecture and strategy it's entirely possible to make MySQL perform well, I was just surprised to see such a dramatic performance difference in some relatively simple queries. It's always going to be necessary to do some work on performance tuning to get the best results, I was just surprised with how much earlier in the process that's required under MySQL.

I keep coming back to trying MySQL and finding it disappointing, usually related to work. I've been using PostgreSQL since 1997 and it's always worked well for me. The most interesting comparison isn't between MySQL/PostgreSQL, since that is a religious war with a lot more people on the MySQL side. The best comparison is how easy/difficult it is to migrate from one DB to another. Migrating from PostgreSQL to Oracle has been very simple when I've done it. Everything just basically works the same out of the box. If it's common to need to do so much MySQL-specific performance tuning, I would see converting to/from it to be a much more difficult project.

I really wonder how much time and effort goes into large MySQL databases and how much is related to how it works. Basically, from a practical standpoint, is that money being spent on people's time costing more than Oracle licenses would? I'm not even a big Oracle fan, but I have developed data warehouses on Oracle and I can't argue with using a tool that works. At the end of the day, finding the right solution to the problem is what counts. It would just be interesting to see cases (other than small, simple databases) where MySQL really shines. A lot of people really like MySQL and use it for some pretty large and business critical applications. I would like to think there's more than ignorance of other databases that drive those decisions. =)

Comment Re:Commercial databases (Score 1) 509

The join worked better in MySQL, taking 2s, compared with 10ms with PostgreSQL. I went with the join because I could also create a view, but was again dismayed that the 2s view took 14 minutes to run when I added "where hostname like 'foo%'" to the query on the view. The moral of the story seems to be that you can make things work with MySQL, as long as you're willing to spend the time figuring out how to do it their way and not trying to use any abstraction like views to keep the structure obvious. I've seen significant improvements with performance tuning in PostgreSQL and Oracle, but never had such simple queries take so long on relatively small data sets out of the box.

Comment Re:Commercial databases (Score 1) 509

There's a level of complexity and size where Oracle does a much better job out of the box than MySQL. Oracle is expensive - it can cost more to license than the expensive hardware it runs on. However, a team of people to address performance issues is not a trivial cost either. Trying to take something huge, like they have now, and switch databases is a giant undertaking and I wouldn't be surprised if it cost more than 10 years of Oracle licensing when you think of all of the manpower required. Oracle is an expensive, bloated pig of a database, but as databases grow in size, Oracle does well and they'll do everything they can to keep you happy. People look at the cost of converting from MySQL to Oracle, but I've never seen anyone try to go the other way around to save some money.

Comment Re:Commercial databases (Score 3, Interesting) 509

Ability to convert depends completely on the application. If the MySQL app written using simple or at least standard SQL, it will be easy to migrate. However, MySQL has some very problematic areas (i.e.: select foo from table1 where id in (select id from table2 where criteria='something')) that make people do some very nonstandard and MySQL-only style fixes to address performance. The query shown with 5000 rows in table1, 50000 in table2, table2 only having 50 rows that met the criteria took ~10ms on PostgreSQL 8.3, and 52 minutes on MySQL 5.1 on the same hardware. The only way I could find to get the ~10ms performance on MySQL was so goofy that MySQL itself refused to allow me to create a view from that select statement.

Converting from PostgreSQL to Oracle has always seemed much easier and smoother, but PostgreSQL isn't as popular as MySQL because it hasn't been as easy to throw hardware at problems with scaling PostgreSQL, whereas MySQL has always made that option easier.

Each database has its own pros and cons, but most times you don't discover how hard it is to migrate until it's too late.

Comment Re:This was the logical end (Score 1) 453

And when those passengers get off the plane thinking they can fly without a plane? I suspect this would have an adverse affect on repeat business. Even worse, all of the people who fly for business would be forced to take the bus so they're remotely functional when they get to their destination.

Comment Re:Bad Precedent (Score 3, Insightful) 142

I suspect that in general, the people who have the time and money to build kit/custom cars have the money to put up a bond to self-insure.

I doubt any auto maker is big enough to lock electric cars out of the market by controlling insurance companies. There will always be someone who is willing to insure electric cars if there are enough of them on the road to make it profitable. Worst case scenario would be the electric car manufacturer also being the insurer. It may be a headache for early adopters, but the market will work it out.

Comment Re:Sounds like a great engine (Score 1) 289

It can if you're talking physics, it's done all the time with RC helicopters which can hover inverted just fine. If you're talking about any aircraft that the FAA would certify, there's no way that would ever happen. The idea of this aircraft being used as drones would provide lots of real world experience in unexpected failure modes without people getting killed.

Comment Re:I work in the Calc Group @ HP (Score 1) 318

Back in the old days, people made stuff without planned obsolescence as a design criteria. I have an HP 49G+ with a keyboard that feels worn out, with the keys being all wobbly, and 48S and 48G which are much older and still feel solid. With a 10+ year head start, almost every other product you can think of would have the older one in worse condition. You can regularly find people on eBay paying over $200 for a HP48GX, because the newer calculators aren't built to be used like the old ones were. Paying more for a slower calculator with less memory isn't because these people are luddites, they just know the difference in quality that comes with that faster processor. I still have my calculators from high school and college (all 20+ years old at this point) and none of them have just died out of the blue. The reason people get irate is because they're not being sold a new calculator like the one they had, they're being sold one that is much cheaper to make and is expected to wear out much faster.

Calculators are things that should last forever with proper care, they're not cell phones which are designed to biodegrade in open air in less than 2 years so they can make you buy another one.

Comment Re:RPN hand calc is not the best way anymore. (Score 1) 318

Calculators are special purpose devices, useful for special purpose applications. I can look at a screen full of horribly formatted data and if I'm adding 10 8-12 digit numbers, I can key them into a calculator faster than I can copy and paste them into a spreadsheet or a calculator program. For thousands of calculations, I'll write a program to parse the data, but for a handful of quick off the cuff calculations a device that has a lot of buttons is much faster and more useful than anything that involves a mouse.

I've been using HP 48's for about 15 years now, so I may be biased towards tools that just work. If eBay prices for old HP 48's are any indication, I'm not the only one who still sees them as useful.

Comment Re:unity (Score 1) 729

Since I couldn't figure out if there was a non-Unity option from within Unity, I was about ready to give up on Ubuntu entirely before I figured out that you could log out and log in with classic to get rid of that steaming pile.

Comment Re:Patience, language, and other tips (Score 1) 175

The very concept of preponing a meeting is intrinsically offensive to Americans. The question presumes that the reason the meeting was scheduled for next week is completely arbitrary, and doesn't represent the first available time that that all parties are available. It implies that in other cultures, a meeting could be scheduled for next month with absolutely no thought put into that date or how it may impact other people's plans or schedules. It's even more offensive when you do confirm that yes, in fact, next month's meeting CAN be preponed to this afternoon, since nobody was actually doing anything.

Slashdot Top Deals

EARTH smog | bricks AIR -- mud -- FIRE soda water | tequila WATER