For Identifiers (just the complete URI and local part, not about mechanisms)
| HDL | PURLz system | ||
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Yes | Yes | |||
Yes | Yes | |||
unique within our PID system without the DNS name portion of the | Yes; very flexible naming, including pseudo/paths | |||
? | Yes | |||
works with VIVO, arXiv, OAIS (CUL), Voyager Catalog, and WorldCat etc. | Yes | does nothing in and of itself to not work with existing systems; | ||
Yes | Yes | |||
Yes | Yes | |||
Yes | Yes | |||
Yes | Yes | |||
completely flexible | Yes | |||
Yes | Yes | |||
Yes | Yes | |||
HDL |
| depends on the length | depends on the length and/or layout |
For Resolver and System
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For Resolver and System
HDL | PURLz | ||||||||||
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Don't know; limited to the practical capacity of the underlying database. | Don't know – mention of 1996 tests resolving 50 resolutions/sec with a database of 500,000 PURLS in Long Introduction to PURLs | ||||||||||
Yes | Yes; PURLz is just a simple HTTP server using MySQL | ||||||||||
Yes | No - alpha stage | ||||||||||
system | Supports billions of identifiers | Robust architecture | Robust implementation | Yes | Yes | ||||||
Yes | Cloning an existing PURL and chaining a PURL | ||||||||||
Yes; the resolvers can't be crawled without providing a dump | Yes; the resolvers can't be crawled without providing a dump | ||||||||||
PID corresponding to every Cornell NetID | useful error when check digit is wrong. Yes | Yes | |||||||||
? | not built in | ||||||||||
Need to avoid unbounded generation of surrogate persistent identifiers | HDL ? |
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? | Depends on the Partial Redirect working – e.g., http://resolver.cornell.edu/netid/bdc34 |
Governance Issues
| HDL | PURLz |
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one-time $50 payment per named resolver (not mirrors) | no | |
Can continue resolve IDs in absence of external organization | Yes | Yes |
HDL is Corporation of National Research Initiatives's Handle system.
PURLz is Zepheira's and OCLC's new persistent URL work.
Footnotes
Uniqueness: We think PURLZ will reject the creation of a duplicate PURL, but we're not entirely sure how it deals with duplication when a PURL name component overlaps a PURL domain component – e.g., if we inadvertently created a domain /a/b/ with resource 1234 and someone later used the name b/1234 in domain /a/. Maybe pure string comparison for non-uniqueness is all that's required, but conventions need to be established to avoid confusion.Anchor unique unique