A temporal database can be represented as a finite sequence of relational instances. Queries over such temporal instances usually map the input sequences to relation instances. Motivated by emerging applications, we are investigating a new type of queries over temporal instances, called t2t queries (temporal-to-temporal queries). The issue is to develop languages able to define mappings from temporal instances to temporal instances. The paper proposes and investigates two types of t2t query languages: pointwise languages and SQTL languages.
['Nicole Bidoit', 'Matthieu Objois']
SQTL: A Preliminary Proposal for a Temporal-to-Temporal Query Language