On 02/04/2011 11:36 PM, Peter Budny wrote: > I'm sorry that you don't seem to see the value in using relations. > > You are definitely correct... there are many ways to represent the same > set of data, with no loss of integrity. Computer programmers often have > to make choices over how complex the data model should be. Some very > large and efficient systems have been built with nothing but key-value > stores. (Google and Amazon have both used this model for some of their > highly-distributed storage systems.) > > This doesn't mean, though, that it's the right solution for everything. > > A major advantage of using relations is that there is a single "entity" > which unambiguously represents a highway like US-26. Without relations, > the only "representation" is a mathematical set of ways.
Some routes don't have a name that are representative of the entire route (such as routes that span many ways with different ways, such as US 26). Likewise, there are some routes that have no ref or network (such as the Lewis & Clark Trail or the Oregon Trail as it is reflected in trailblazer signage today). Further, especially with autotrails, these ways lack a ref but share a common name that is different than the name than it's member ways (such was the Oregon Trail where it is the Columbia River Freeway, and the parallel Mt. Hood Highway simultaneously, or the Lewis & Clark Trail, where it spans OR 6, US 30, Columbia House Boulevard, and many other parallel roads where their actual route approximated existing present day roads with such trailblazers). > This causes a lot of problems, because there's no obvious place to put > information that belongs to the whole road, like the official_name. > Does it go on one way? On all of them? What if two ways have > official_name tags that don't match? Even if your tags are correct, it > could cause users to have to look through a LOT of data to find a piece > of information. Where are you getting that "official_name" is widely accepted in the first place?
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