GTL-a graphical language for temporal data

A novel graphical query language for temporal relational data is presented. The query language GTL combines capabilities of temporal and graphical database languages. GTL-queries may be related to single database states (e.g. is there a database state where condition c1 holds?) or to sequences of database states (e.g. is there a database state sequence where first c1 holds, then c2, and finally c3?). In GTL, relations are represented by graphical symbols and temporal relationships between database states can be expressed along an implicit time axis. The underlying temporal data model abstracts from implementation aspects, e.g. it is not relevant whether tuple time stamping or attribute time stamping, single- or double-time stamping is used