Adding time dimension to relational model and extending relational algebra

Tansel, Abdullah Uz

doi:10.1016/0306-4379(86)90014-1

Cited by 105 publications

(38 citation statements)

References 4 publications

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“…The cost of a tuple(row) z in relation instance t r is the summation of the cost of all subsets attributes equals to (6) as stated in (1), (2), (3) and (4)   311 | P a g e www.ijacsa.thesai.org…”

Section:   Z Costmentioning

confidence: 99%

A Mathematical Model for Comparing Memory Storage of Three Interval-Based Parametric Temporal Database Models

Alromema¹,

Rahim²,

Albidewi³

2017

ijacsa

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Abstract-Interval-BasedTo this end, a mathematical model for comparing a three different storage models is demonstrated to illustrate that the proposed model is more efficient than other approaches under certain conditions. The simulation results showed that the proposed model overcomes the needless redundancy of data, achieves saving in memory storage, and it is easy to be implemented in relational data model or to be adapted with a production systems that need to track temporal aspects of functioning database Systems.

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Section:   Z Costmentioning

confidence: 99%

A Mathematical Model for Comparing Memory Storage of Three Interval-Based Parametric Temporal Database Models

Alromema¹,

Rahim²,

Albidewi³

2017

ijacsa

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“…The relational model (Codd 1970) and its extension (Codd 1979) provide for a logically complete language with which to describe data transformations (Codd 1972) and a number of time-related algebras have been proposed to extend the static relational model (Clifford and Tansel 1985;Tansel 1986;Clifford and Croker 1987;McKenzie and Snodgrass 1987a, 1987cGadia 1988;Lorentzos and Johnson 1988;Sarda 1990;Tuzhilin and Clifford 1990). A survey of valid-time and bitemporal algebras is given in McKenzie and Snodgrass (1991) which includes an evaluation of twelve representative algebras against various criteria.…”

Section: Algebras Supporting Schema Evolutionmentioning

confidence: 99%

A survey of schema versioning issues for database systems

Roddick

1995

Information and Software Technology

228

117

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“…Most of the temporal data models that have appeared in the literature have incorporated valid time as the single temporal dimension. These data models, commonly called valid-time or historical models, and sometimes real-world time, intrinsic time, logical time, or data time models include, among others, the models proposed in [Jones and Mason, 1980, Ben-Zvi, 1982, Clifford and Warren, 1983, Ariav, 1986, Tansel, 1986, Clifford and Croker, 1987, Lorentzos, 1987, Snodgrass, 1987, Gadia, 1988a, Navathe and Ahmed, 1989*cda, 19901. Transaction Time According t o [Jensen et al, 19921, " t h e transaction time of a database fact is the time when the fact is current in the database and may be retrieved." Unlike valid time, transaction time is not under the explicit control of the user.…”

Section: Kinds Of Timementioning

confidence: 99%

“…A second set of proposals for extending the relational model ( [Clifford, 1982, Tansel, 1986, Clifford and Croker, 1987, Gadia, 1988a breaks free of the first normal form constraint of the standard relational data model. Under these proposals it becomes possible to represent all of the data pertaining to a real world object in a single historical tuple whicfi groups toqether all of the information about that object.…”

Section: Temporally Grouped Modelsmentioning

confidence: 99%

“…There have been several query languages proposed for tlie temporally grouped model in the past, including [Clifford and Tansel, 1985, Tansel, 1986, Clifford and Croker, 1987, Gadia, 1988a. In [Clifford et al, 19943, a temporal calculus for the temporally grouped model, Lh, was presented, and it was argued that this calculus has all tlie minimally necessary important features that a temporally grouped model should have.…”

Section: Querying Temporally Grouped Modelsmentioning

confidence: 99%

See 1 more Smart Citation

On Data Representation and Use in a Temporal Relational DBMS

Clifford

Croker

Tuzhilin

1996

Information Systems Research

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Numerous proposals for extending the relational data model to incorporate the temporal dimension of data have appeared over the past decade. It has long been known that these proposals have adopted one of two basic approaches to the incorporation of time into the extended relational model. Recent work formally contrasted the expressive power of these two approaches, termed temporally ungrouped and temporally grouped, and demonstrated that the temporally grouped models are more expressive. IN the temporally ungrouped models, the temporal dimension is added through the addition of some number of distinguished attributes to the schema of each relation, and each tuple is "stamped" with temporal values for these attributes. By contrast, in temporally grouped models the temporal dimension is added to the types of values that serve as the domain of each ordinary attribute, and the application's schema is left intact. The recent appearance of TSQL2, a temporal extension to the SQL-92 standard based upon the temporally ungrouped paradigm, means that it is likely that commercial DBMS's will be extended to support time in this weaker way. Thus the distinction between these two approaches -and its impact on the day-to-day user of a DBMS -is of increasing relevance to the database practitioner and the database user community. In this paper we address this issue from the practical perspective of such a user. Through a series of example queries and updates, we illustrate the differences between these two approaches and demonstrate that the temporally grouped approach more adequately captures the semantics of historical data.

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Adding time dimension to relational model and extending relational algebra

Cited by 105 publications

References 4 publications

A Mathematical Model for Comparing Memory Storage of Three Interval-Based Parametric Temporal Database Models

A Mathematical Model for Comparing Memory Storage of Three Interval-Based Parametric Temporal Database Models

A survey of schema versioning issues for database systems

On Data Representation and Use in a Temporal Relational DBMS

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