A glossary of temporal database concepts

Abstract

This glossary contains concepts specific to temporal databases that are well-defined, well understood, and widely used. In addition to defining and naming the concepts, the glossary also explains the decisions made. It lists competing alternatives and discusses the pros and cons of these. It also includes evaluation criteria for the naming of concepts.This paper is a structured presentation of the results of e-mail discussions initiated during the preparation of the first book on temporal databases, Temporal Databases: Theory, Design, and Implementation, published by Benjamin/Cummings, to appear January 1993. Independently of the book, an initiative aimed at designing a consensus Temporal SQL is under way. The paper is a contribution towards establishing common terminology, an initial subtask of this initiative.

Checking and Verifying Temporal Data Validity Using Valid Time Temporal Dimension and Queries in Oracle 12C

“…Valid time allows temporal database to associate a valid time dimension with a relation or table and data said to be valid depending on its validity of time. This validity of time is determined by start and end dates or timestamps of the period for which a given tuple or record is considered to be valid [11].…”

“…Oracle 12c supports temporal validity using Oracle flashback Technology using valid time period clauses like AS OF and VERSIONS BETWEEN [11].…”

On Data Representation and Use in a Temporal Relational DBMS

“…In a temporal database, tilerefore, it is unreasonable to impose this strict requirement. Thus, the temporal database comnrunity developed the notion of a snapshot key [Jensen et al, 19941 as the appropriate extension to the temporal case of the notion of a relational key in so-called static or snapshot relations.…”

“…An outgrowth of this workshop was the creation of the TSQL2 Language Design Committee, whose mission was to develop an extension of the language SQL-92, called W Q L 2 , to incorporate treatment of the temporal dimension into SQL-92. The committee has issued a report [Snodgrass et al, 1994b1 containing a complete syntactic extension to SQL, for which informal semantics has been provided via a series of "commentaries" some of which were also published as separate reports, such as "A TSQL2 Tutorial7' ( [Snodgrass et al, 1994a]), "A Consensus Glossary of Temporal Database Concepts" ( [Jensen et al, 19941). Finally, the complete description of the TSQL2 language is presented in the book [Snodgrass, 19951. It was the goal of DARPA and NSF, and it is expected by the committee, that their report will have a widespread impact on the SQL industry.…”

Applying transition rules to bitemporal deductive databases for integrity constraint checking

“…Valid time is the time when the fact is true in the modelled reality, while transaction time is the time when the fact is stored in the database. In a consensus glossary of temporal database concepts [8], a deductive database that supports valid time and transaction time is called a bitemporal deductive database and we denote it bt-ddb.…”