Videotutorial 5: Fundamentos de Bases de Datos

Study Notes

This videotutorial covers database normalization.
The tutorial includes a complete exercise, Entity-Relationship (E-R) Model, Relational Model, and key normalization concepts.
A summary of general concepts is also provided.

The exercise involves creating an entity-relationship diagram and converting it into a relational model, following the first normal form.
The exercise describes a database for a course with students and assignments (PACs).
Each student has a unique ID, name, age, and languages spoken.
Each PAC has a unique ID, number of questions, opening and closing dates, the number of days it is open, and the maximum score.
Each question in a PAC is worth 0.2 points. This allows calculating the maximum score for each PAC.

Shows the relationship between ALUMNO, HACER, and PAC tables.
The tables include attributes like id_alu, edad, Nombre, nota, tiempo, id_pac, fecha_aper, dias_apertura, fecha_cierre, número_preg, and puntuación_max.

The exercise showcases the normalization of tables to the third normal form (3NF).
Shows the structure of the ALUMNO, PAC, ALUMNO_PAC, and IDIOMAS_ALUMNOS tables.
The ALUMNO table contains unique student identifiers.
The PAC table includes data related to assignments.
The ALUMNO_PAC table links students and assignments with attributes like the student's score and time spent on each assignment (PAC).
The IDIOMAS_ALUMNOS table manages the languages a student knows.

This exercise focuses on normalizing the ALQUILERES table.
The ALQUILERES table data is explained, including FechaDeAlquiler (PK), CódigoLibroAlquilado (PK), and CódigoUsuario (PK)
The table includes multiple attributes like book title, editorial names, and user attributes.
The tutorial highlights that a user can rent the same book multiple times.
Updating user phone numbers and editorial locations proves problematic due to the data structure in the ALQUILERES table.

The solution shows the breakdown of the ALQUILERES table into multiple, interconnected tables.
This breakdown is done to improve data integrity and efficiency.
The process of normalization is described.
As a result the single original table is transformed into 6 tables that are interconnected.

Explains how to eliminate multi-valued fields.
Provides details on creating new tables to organize multi-valued attributes (e.g., TELEFONOS, AUTORES).

Explains how the normalized data is further decomposed to resolve partial dependencies.
This ensures that non-key attributes rely on the entire primary key. ALQUILERES table is further normalized.
Relationships are described with the inclusion of new tables like LIBROS, EDITORIALES, and USUARIOS.

The video clarifies how LIBROS table can be further normalized to eliminate transitive dependencies.
This step removes redundancy in the database.
The solution explains the creation of a new table EDITORIALES.

This section summarizes the process of converting a single table into multiple tables with better structure.
Creating related tables to improve data accuracy and consistency is highlighted.

This part of the tutorial discusses planning and developing a database, considering conceptual, logical, and physical levels.
The different phases involved are explained, along with details about the database design, implementation choices, and efficiency.

The presentation contains review questions on the concepts discussed.
The questions include the creation of E-R diagrams for differing scenarios.
There's a task to normalize, creating models from tables using 1NF, 2NF, and 3NF steps.

Emphasizes the importance of database design considerations.
The normalization process is demonstrated as a key concept in structuring efficient database systems.