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A Study of Library Databases by Translating Those SQL Queries Into Relational Algebra and Generating Query Trees

Even in this World Wide Web era where there is unrestricted access to a lot of articles and books at a mouse’s click, the role of an organized library is immense. It is vital to have effective software to manage various functions in a library and the fundamental for effective software is the underlying database access and the queries used. And hence library databases become our use-case for this study. This paper starts off with considering a basic ER model of a typical library relational database. We would also list all the basic use–cases in a library management system. The next part of the paper deals with the sql queries used for performing certain functions in a library database management system. Along with the queries, we would generate reports for some of the use cases. The final section of the paper forms the crux of this library database study, wherein we would dwell on the concepts of query processing and query optimization in the relational database domain. We would analyze the above mentioned queries, by translating the query into a relational algebra expression and generating a query tree for the same. By converting algebra, we look at optimizing the query, and by generating a query tree, we would come up a cheapest cost plan.