Data Management Systems (DBMS) Overview

A thing or concept, either real or abstract, that is represented in a database.

A description of an entity's properties, also known as attributes or characteristics.

A unique property or set of properties that identifies a specific instance of an entity.

A property of an entity that can have one or more values.

A property that uniquely identifies each instance of an entity within a database.

A unique identifier assigned to each invoice.

The amount of money a patient needs to pay for the invoice.

A unique identifier assigned to each patient.

The process of organizing how data is stored and accessed in a database to speed up search operations.

A special index that makes it fast to find records based on a patient's identification number.

Dividing a large database into smaller parts to improve query performance.

Storing frequently used query results to make future access faster.

Analyzing how queries are executed to find ways to make them run faster.

The ability to represent data in simple tables, making it easy to understand and work with.

A set of operations that allow users to manipulate data in the database, including searching, updating, adding, deleting, and generating reports.

The ability to change the physical storage and access methods without impacting the way users view or access the data.

The ability to change the logical structure of the database without affecting the applications that use it.

Rules that enforce data integrity and consistency, ensuring data accuracy and reliability.

A link between two or more entities in a database.

A property that describes the specific details of an association, highlighting the nature of the link between the entities.

The number of occurrences that an entity can be involved in an association. It has a minimum and maximum bound.

The minimum number of times an entity must be involved in an association.

The maximum number of times an entity can be involved in an association.

Represents one occurrence of an entity.

The number of entity occurrences on one side of an association can be linked to the number of entity occurrences on the other side. It indicates the link between the maximum and minimum bounds on both sides.

Cardinality helps us understand the constraints of the relationship between entities, helping in accurate database design. If a patient can have multiple consultations with different doctors, the cardinality would reflect this.

A table that represents an entity in a relational database schema. It consists of rows (representing instances of the entity) and columns (representing the entity's attributes). For example, a 'Doctor' table would have rows for each doctor and columns for their ID, name, specialty, etc.

A table that represents a relationship between two or more entities in a relational database. It typically includes foreign keys that link to the primary keys of the participating entities and may also include attributes specific to the relationship. For example, a 'Consultation' table might have foreign keys linking to 'Doctor' and 'Patient' tables and attributes like date and time of the consultation.

A column in a table that references the primary key of another table. Foreign keys help establish relationships between tables and enforce data integrity by ensuring consistency across tables.

The process of converting an entity-relationship (E-R) diagram, which represents a conceptual database model, into a relational database schema. This involves defining tables, columns, primary keys, and foreign keys to accurately represent the entities and relationships depicted in the E-R diagram.

Storing the same information repeatedly in multiple locations, leading to wasted space and potential data inconsistencies.

Keeping data consistent across different copies is challenging due to redundancy and manual file management.

Making structural changes often requires manual updates in multiple locations, which can be tedious and error-prone.

Accessing data sequentially requires reading through all the data before reaching the desired information, which can be slow for large datasets.

Security relies heavily on the operating system and file permissions, lacking the advanced features found in databases.

Sharing data between applications requires complex mechanisms to ensure consistency, as there is no built-in integration.

Performance degrades with an increase in data volume due to sequential search and redundancy.

Lack of advanced features for transaction management makes it difficult to ensure data consistency during multiple operations.