Transforming a Multi-value Database System into a Relational Database System for Faster Querying

Abstract

When the data is fluid and relationships among attributes are getting complex and are changing rapidly over time, a Multi-value Database Management System (MVDBMS) can provide a great deal of support to handle that. MVDBMSs can handle attributes taking a list of values unlike a Relational Database Management System (RDBMS) that can only accept single-valued attributes to conform first normal form (1NF). It is suitable to use multi-valued database in case where a list of values can be assigned to a single attribute in a particular record. In this case, MVDBMS can save a lot of storage space and it is quite efficient to retrieve a specific record. However, when it comes into retrieving data based on Select- Project-Join (SPJ) queries, a multi-valued database cannot handle these queries in a straightforward manner.In this thesis, we propose techniques to transform a MVDBMS into a RDBMS for faster querying and retrieval. Therefore, we introduce two novel techniques: one of them will generate database schema conforming to Third Normal Form (3NF) and the other will be in First Normal Form (1NF). 3NF is a normal form that is used in normalizing a database design to reduce the duplication of data and ensure referential integrity. In 1NF the domain of each attribute contains only atomic (indivisible) values, and the value of each attribute contains only a single value from that domain. 1NF create a separate table for each set of related data, so a large number of attributes can be stored into one table but in a set of related data there is a high possibility of data duplicity. In 3NF all the attributes in a table are determined only by the candidate keys of that table and not by any non-prime attributes; so data duplicity will be reduced but to establish referential integrity it requires more table. As the number of table increase, it will require more joining operation which will cost time.