Persistent Identification

The Library persistenty identifies digital collections, documents, and services in several different ways:

Persistent URLs which are implemented as Apache HTTPD server-side redirects, sometimes referred to locally as "handles." An example is http://www.lib.uchicago.edu/h/factiva

These are used to provide persistent names for licensed and locally created electronic resources (databases, web pages, etc.). They are simple to create, maintain, and scale well.

Persistent URLs in 856s in the library catalog and WorldCat, and persistent identifiers in OAI responses, formed according to these conventions. An example is http://pi.lib.uchicago.edu/1001/dig/chopin/001

These are used to provide persistent identifiers for locally created digital resoures. Because many of them use the same pattern, these patterns are computed algorithmically. Where there is no pattern, one-to-one mappings between identifier and resource are entered.

PURLs in 856s in the library catalog and WorldCat. An example is http://bibpurl.oclc.org/web/4841

This solution has been used in some cases.

The Library also uses DNS (Domain Name Service) aliases, e.g., chopin.lib.uchicago.edu, which refer to virtual hosts as defined in a web server's configuration file, e.g., http://chopin.lib.uchicago.edu/. These aliases mask the underlying hostname so that services using them, typically major, discrete digital collections or major websites such as http://www.lib.uchicago.edu/, may be referred to persistently despite any underlying hosting changes that may occur, for example, because of hardware upgrades.