Wednesday 22 August 2012

OSM should not have a database

Openstreetmap should not have a database. Having a database positively hurts the whole community. There, I've said it and I feel better already.

Where there is a database there are nerdy types who want to normalise it, formalise the ontology of it, rationalise it, enhance its performance and all the other things computer science bods and other nerds love to do. They do it because their training or their gut feel tells them it must be an improvement that everyone will welcome it. They are wrong.

If OSM didn't have a database, it would be easier to explain that we don't do that, and we don't want you to do that either. It would be easier to direct these meddling nuisances to some other project, maybe opendatabasewrangling or openstringuntangling. That way we could keep the freedom to carefully choose the tags we use without the risk that some prat would mass-edit them into his view of an organised world, losing all the detail and nuances carefully placed there by hundreds of other mappers. The really, really annoying thing is that most of these people don't actually consume the data in a useful way, it just seems like a good idea to them. If they did use the data they would quickly see that selecting the data you want with a little preprocessing is easy and you always have to do this, so adding some extras to cope with variety is fairly simple. Write the code once and it works over and over again.

Of course we need to store the data somewhere and in reality that needs to be a database, such as the one we have. I must make it clear that I'm not criticising the database, it's design or the way it is managed or run at all, just the fact that something called a database attracts unwelcome urges from a few people. Maybe we could just stop calling it a database. Can we rename it to the tag-pile, or the OSM toy-box or anything that doesn't convey 'database'?

I wish the people who want to reduce the tags to a proscribed list well - I just wish them well somewhere outside of OSM. If they want an organised, limited list of tags, take OSM data and play with it in their world as they want to - just don't upload the changes as a mass-edit back into our toy-box. There is real value in nuanced data and, more importantly, real value in not upsetting the mappers whose carefully chosen tags get squashed to homogenised blandness by these unthinking mass-editors.

What would you rename the database the place we store our data to?

Thursday 2 August 2012

Keeping stuff up-to-date

It is all very well mapping an area, but things keep changing. A new £90 million hospital has just opened on the outskirts of Beverley and so as we passed it today we dropped in to grab a look around. Well, a look at just the grounds - I've had enough of the inside of hospitals. It was a bit unusual in two ways. Firstly there was a lot of car parking, so much so that there were many empty parking places. At the other local hospitals parking is a nightmare. The second thing was completely unexpected to me: an electric vehicle charging point. The two bays were labelled as Hybrid Vehicle Charging, but surely a hybrid doesn't need charging as much as a totally electric vehicle. A hybrid, by definition, has more than one means of power, whereas an electric vehicle needs to charge or stops.

I was able to trace the outline of the new building from the latest Bing imagery, which are very helpful, well aligned and now less than a year old - the previous ones were up to eleven years old. Nearby we spotted a new allotment site and a short detour helped add that to the map too. It is not a council site but a private one. It looks a good site. It was still a field on the new imagery, so it is pretty new.

As we drove through Beverley I noticed a lot of the residential streets have new 20 mph speed limits, so they all need surveying and updating. Speed limits don't take long to survey, so an hour wandering around should do it.

I rather enjoy looking for these changes and adding them to the map. I'm sure OSM is the only map to have both the hospital and the allotments on it right now - in fact how many other maps have allotments at all?