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A candidate key is a minimal set of attributes in a relational database table that can uniquely identify a tuple. It is essential for ensuring data integrity by preventing duplicate entries and forms the basis for identifying primary keys.
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A relational database is a structured collection of data that uses a schema to define relationships between tables, enabling efficient data retrieval and manipulation through SQL queries. It ensures data integrity and reduces redundancy by organizing data into tables where each row is a unique record identified by a primary key.
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A tuple is an immutable, ordered collection of elements, often used in programming to store related data. Unlike lists, tuples cannot be modified after creation, making them useful for fixed data structures and as keys in dictionaries due to their hashable nature.
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An attribute is a characteristic or quality that defines an object, entity, or concept, often used to describe properties or features in various contexts such as databases, programming, and machine learning. Attributes are crucial for differentiating and categorizing data, enabling efficient data management, analysis, and interpretation.
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A primary key is a unique identifier for a record in a database table, ensuring that each entry is distinct and easily retrievable. It is essential for maintaining data integrity and establishing relationships between tables in a relational database management system.
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Data integrity refers to the accuracy, consistency, and reliability of data throughout its lifecycle, ensuring that it remains unaltered and trustworthy for decision-making and analysis. It is crucial for maintaining the credibility of databases and information systems, and involves various practices and technologies to prevent unauthorized access or corruption.
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A uniqueness constraint makes sure that something special, like a name or a number, is not repeated anywhere else. It helps keep things organized and makes sure everyone has their own special spot or thing.
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Normalization is a process in database design that organizes data to reduce redundancy and improve data integrity by dividing large tables into smaller, related tables. It involves applying a series of rules or normal forms to ensure that the database is efficient, consistent, and scalable.
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A superkey is a set of one or more attributes that, taken collectively, can uniquely identify a tuple within a relational database table. It is a fundamental concept in database design, ensuring that each record is distinct and can be efficiently retrieved or manipulated.
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Minimality is a principle that emphasizes the use of the least amount of resources, elements, or complexity necessary to achieve a desired effect or function. It is often applied in fields like design, art, and mathematics to enhance clarity, efficiency, and elegance.
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Functional dependency is a constraint between two sets of attributes in a relational database, where one set uniquely determines another. It is fundamental to database normalization, ensuring data integrity and reducing redundancy by organizing data efficiently.
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Closure of attributes refers to the complete set of attributes that can be functionally determined by a given set of attributes in a relational database schema. It is used to identify all possible dependencies and plays a crucial role in normalization and database design optimization.
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Partial dependency refers to a situation in a database where a non-prime attribute is functionally dependent on part of a candidate key, rather than the whole key. This often leads to redundancy and anomalies, and is typically resolved by normalizing the database to Third Normal Form (3NF).
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A non-prime attribute is an attribute in a database table that is not part of any candidate key, meaning it does not contribute to the uniqueness of a tuple within a relation. These attributes are often examined in normalization processes to ensure the database structure supports efficient data management and integrity.
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Boyce-Codd Normal Form (BCNF) is a database normalization form used to eliminate redundancy and ensure data integrity by requiring that every determinant in a relation is a candidate key. It is a stricter version of the Third Normal Form (3NF), addressing anomalies that 3NF may not handle by ensuring that no non-trivial functional dependencies exist unless they are on superkeys.
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A unique constraint is a database rule that ensures all values in a column or a set of columns are distinct across the rows, preventing duplicate entries. It is crucial for maintaining data integrity and is often used to enforce the uniqueness of identifiers like primary keys or any other candidate keys.
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Fifth Normal Form (5NF), also known as Project-Join Normal Form (PJNF), is the highest level of database normalization aimed at eliminating redundancy in relational databases by ensuring that every join dependency in the database is a consequence of the candidate keys. It is particularly useful in complex databases where data is decomposed into smaller tables without losing any information or introducing redundancy, ensuring data integrity and consistency.
Boyce-Codd Normal Form (BCNF) is a higher version of database normalization that aims to eliminate redundancy and dependency anomalies by ensuring that every determinant is a candidate key. It is stricter than the Third Normal Form (3NF) and is used to ensure the integrity and efficiency of database designs.
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Database normalization is a process used to organize a database into tables and columns to reduce data redundancy and improve data integrity. It involves dividing large tables into smaller, related tables and defining relationships between them to ensure data dependencies make sense and are logical.
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