Best Practice for URI construction?

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

 

A URI is used to "identify" a resource:

 

A Uniform Resource Identifier (URI) is a compact sequence of characters that identifies an abstract or physical resource.[1]

 

I would like to bound the following discussion by considering just URLs that use the http scheme.

 

As I see it, there are two main approaches to constructing a URL to identify a resource:

 

Approach 1. URL Construction using Parent/Child Relationships

 

Here's an example of a URL that uses this approach:

 

http://www.location.org/US/MA/Boston

 

After the [host] (www.location.org) there are a series of slash-delimited names.  The name to the left of a slash is the parent.  The name to the right of a slash is the child.

 

Approach 2. URL Construction using Key-Value Pairs plus Conjunction

 

This second approach is exemplified with this URL:

 

http://www.location.org?country=US&state=MA&city=Boston

 

After the [host] there is the query string delimiter (?) followed by one or more key=value pairs ANDed together.

 

Hybrids of the above two approaches are also possible.  For example:

 

http://www.location.org/US/MA?city=Boston

 

Questions

 

(1) The above URLs (I believe) are expressing the same thing - they are identifying the same resource.  So which is "better"?

 

(2) As was noted at the top, the purpose of a URL is to "identify" a resource.  Can every resource in the universe be identified using the above two approaches?  Are there resources that do not lend themselves to identification using the above two approaches?

 

/Roger

 

[1] http://www.gbiv.com/protocols/uri/rfc/rfc3986.html