My current thoughts on datasets are summarized in the paper
Datasets for the GRID (word, pdf) (last updated September 2003)
DC1 and DC2 Dataset catalogs for ATLAS
Here are some older papers:
November 2002 - Comparison with event collections (word, pdf)
November 2002 - Dataset properties (word, pdf).
July 2002 - Event dataset requirements (word,
pdf).
This and the implementation below envisions a dataset that holds
only event data.
Use cases and design have not been documented but I will do so if there is demand. Follow the packages link below to see the implementation.