University of Twente Student Theses
Encapsulating a database with safe database methods
Haile, Eyerusalem Berhane (2011) Encapsulating a database with safe database methods.
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| Abstract: | Several studies have been made in database systems to provide good integrity management, however, it still is difficult to implement all kinds of integrity constraints and enforce them especially in the presence of complex constraints. Not much is done in the field of functional design of databases unlike the structural database design. The purpose of this paper is to present an approach of functional database design to provide a non-constraint violating transaction, by encapsulating the database with a suite of functions that are safe from violating constraints, assuming the database was kept at a consistent state initially, and allowing users to access the database through those functions only. The methods that are to encapsulate the database are developed in three steps, initially by creating a solid and robust object method, then lift it to become a table method or develop a table method by directly coding it using the object methods, and finally create a solid and robust database method using the table methods. There are four lifting operators developed, three of which are to lift object methods to become table method while one is from table to database method. Each of the methods listed is responsible for controlling constraint maintenance at its own granularity level. Initially the conceptual design was made using end-user-oriented expressions that are defined using fundamental building blocks of semantics designed to express that intuition of “take the whole dataset leave it intact except for some intended changes”. Next a methodology on how to implement the conceptually designed methods in PostgreSQL, using PL/pgSQL is provided. With some of the limitations present in PostgreSQL we have provided some implementation tricks in the methodology. At the end a case study was develop to show how to use the methodology in action. Keywords Database methods, lifting operators, encapsulation, constraint maintenance, set returning function (SRF) |
| Item Type: | Essay (Master) |
| Faculty: | ITC: Faculty of Geo-information Science and Earth Observation |
| Programme: | Geoinformation Science and Earth Observation MSc (75014) |
| Link to this item: | https://purl.utwente.nl/essays/92785 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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