The University of Arizona

Temporal Access for Users


TAU is an umbrella project comprised of a number of inter-related and complementary projects, all with the goal of providing to users, through sophisticated user languages and APIs, facilities to manage time-oriented data.

The name of the project was inspired by three associations. The acronym is "Temporal Access for Users" which concisely describes the project. The project name is the English spelling of the Greek letter "τ", which is commonly used in scientific formalisms to denote time. And the Greek letter resembles an umbrella, emphasizing the sub-projects comprising this overall project.

Our goal is to realize the theoretical advances over the last decade in temporal databases in practical, efficient, correct, well-engineered and documented interfaces that can be used by the application developer or database user. A second, consistent goal is to leverage each system with the other systems, to provide comprehensive support. Hence, the temporal data types and granularities made available in τZaman can be utilized in XSchema directly and also in τXSchema, the latter to describe time-varying XML data, stored efficiently by τBerkeleyDB, supported in Persistent Stored Modules in τPSM, queried and returned as a result by τXQuery, evaluated for correctness and performance in τBench, and utilized in τDOM when manipulating time-varying XML documents.

Constituent Projects


(Note that there was an unrelated project also called TAU at the University of Manchester Institute of Science and Technology, to investigate the development of temporal extensions to the object-oriented paradigm. That project, active from 1996 to 2000, was named after the elementary particle (also called the "tauon" or "tau lepton") discovered by Martin Perl, which has a a lifespan of merely one femtosecond, one million billionth of a second. Also, Tel Aviv University sometimes uses the acronym TAU. Finally, there is a profiling and tracing toolkit, the so-called Tuning and Analysis Utilities, developed at the University of Oregon; the entire system is called the "TAU Performance System".)

Webmaster: Kyri Pavlou