Data Bases

The course introduces students into the area of databases. Basic concepts and notions of database management systems (DBMS) and their architecture will be presented. Respective data structures, as well as DDL and DML language constructions, will be discussed. Mathematical fundamentals of relational databases will be presented. Principles of designing databases will be outlined. Relational query languages, such as QBE, SQL and PL/SQL, will be presented.


Lecture contents
Architecture of database systems: Basic notions, database schema, DDL and DML languages, DBMS`s functions.

Data structures: data levels; data models (hierarchical, relational, object-oriented), semantics of data, navigational languages versus relational languages.

Mathematical foundations of relational model: Relation as a mathematical concept, relational schema. Integrity constraints - formal approach. Relational algebra (with extensions by Date), tuple-oriented calculus, domain-oriented calculus. Notion of a key of the relation, functional dependencies, Armstrong axioms, schemata decomposition, normalization of relational schema.

Introduction to designing databases: ER model. Pronciples of describing database structures by means of entities, classes and relationships among them. Basic design decisions on conceptual level (mapping relationship classes to entity classes, multivalued and optional attributes, weak relationships, etc.). Mapping of ER to relational model. Specification of database structure in DDL. Defining domain and semantic integrity constraints. Description of database structure by means of data dictionary.

Database languages (QBE, SQL, PL/SQL): DML constructs in QBE. DML constructs in SQL: SELECT phrase as a specification of a sequence of operations on tables. Syntax and semantics of basic SELECT phrases, conceptual processing order of sections (clauses). Acceptable expressions in particular clauses. Nested constructs: correlated and uncorrelated subgueries. Pronciples of formulating queries in the form of SELECT expressions: equivalent forms. Declarative and procedural semantics of the SELECT expressions. Three-valued logic in SQL: a problem of NULL values, anomalies resulting from NULL values. Virtual tables (views), acceptable operations on views. PL/SQL as a procedural extension of SQL. Cursos, embedded procedures, and triggers.



Projects contents
The purpose is to design a database structure for a simple database system and to define its relational implementation with a CASE tool. Sample client database applications will be created: SQL commands implementing given database operations will be devised and embedded in a simple interaction program created with a software builder tool.


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Literature (mandatory):


1. Elmasri R., Navathe S.B., Fundamentals of Database Systems, The Benjamin/Cummings Publishing Comp., Inc.


Literature (optional):


1. Ullman J.D.,Principles of Database and Knowledge Based Systems, Computer Science Press, Vol. 1


2. Date C., An Introduction to Database Systems, Adison Wesley, System Programming Series, vol. 1