Directories 101
Role of the directory
To bring together information from disparate, independent sources and present it in a unified, consistent way.
What a directory is
- A consistent, comprehensive source of current data.
- A university resource.
- A manifestation of an underlying database or sets of databases.
- A database that is often searched but rarely written (therefore, it is optimized for "reads").
- Accessible by diverse applications from diverse locations
- Directory model:
schema
a set of rules that determines what data can be stored in the directory and how directory servers and clients should treat information during directory operations.
namespace
means by which information is referenced in the directory.
entry
collection of data about an object – the basic unit of information in the directory.
attribute
holds specific data which describes one trait of the object. Every directory entry has a set of required attributes and a set of allowed attributes.
attribute type
describes the kind of information contained in the attribute.
attribute value
the actual data; i.e., the contents of the field.
identifiers
indices into the database.
What a directory is not
- A database (relational, transaction-oriented).
- A transaction processor.
Challenges
- Identifying data sources, data owners and directory-appropriate data.
- Establishing key identifiers.
- Deciding whether the directory scheme should be campus-specific or university-wide (unified namespace).
- Public data vs. private data issues.
- Determining and reaching agreement on access rights, access grouping granularity.
- Establishing security.
- Synchronization and integration with other campus and university directories.
- Deciding policy regarding direct update to the directory vs. updates via external data sources.
- Considerations of interoperability between institutions of higher education.