Introduction

Maintaining a precise, well-defined, and intuitive technical language is important to the scientific community. In this glossary we propose definitions and names of a range of concepts specific to temporal databases that are well-defined, well understood, and widely used. The glossary meets a need for creating a higher degree of consensus on the definition and naming of central concepts from within the field. The use of inconsistent terminology adversely affects the accessibility of the literature and has also an adverse effect on progress.

Being a proposal, simply stating definitions and names would be counter-productive and against the intentions. Consequently, the paper presents alternatives and discusses why the specific decisions were made. When several alternative names for a concept were considered before a decision was made, the paper not only states that decision, but it also presents the alternatives and discusses why the decision was made. This glossary arose from e-mail discussions among the authors considering appropriate terminology for a forthcoming collection of articles [TCG+92]. A list of papers and other bibliographies that define and use the concepts discussed here may be found elsewhere [Soo91].

A consensus Temporal SQL is being designed. An initial white paper [Sno92] lists fifteen design subtasks. This paper addresses one of the first tasks, the establishment of common terminology.

The next section first presents a list of relevance criteria for concepts. All concepts included in the glossary satisfy these criteria. Second, it defines a number of evaluation criteria for the naming of concepts. These criteria have emerged from the discussions. Third, the structure of the proposal is described. Section  presents the proposed terms and concepts.