数据库原理基本概念英文解释
Database principles refer to the fundamental concepts that define the structure, functionality, and management of a
database system. These principles are essential for designing, implementing, and maintaining a reliable and efficient database. In this essay, I will discuss the basic concepts and principles
of databases in detail, including data modeling, data integrity, normalization, indexing, and database transactions.
Data Modeling:
Data modeling is the process of defining the structure and relationships of the data in a database. It involves identifying and organizing the various entities, attributes, and
relationships that exist within the domain of an application. There are different types of data models, such as the conceptual, logical, and physical data models. The conceptual data model describes the high-level view of the data, the logical data
model represents the data structure using entities, attributes, and relationships, and the physical data model maps the logical data model to a specific database management system.
Data Integrity:
Data integrity ensures the accuracy, consistency, and reliability of data stored in a database. It ensures that the data values conform to defined rules or constraints. There are
four types of data integrity: entity integrity, referential integrity, domain integrity, and user-defined integrity. Entity integrity ensures that each row in a table has a unique identifier. Referential integrity ensures that relationships between tables are maintained. Domain integrity ensures that data values are within certain predefined ranges. User-defined integrity ensures that additional business rules or constraints are enforced.
Normalization:
Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. It involves breaking down larger tables into smaller, more manageable entities and establishing relationships between them. The normalization process follows a series of normal forms, such as First Normal Form (1NF), Second Normal Form (2NF), Third Normal Form (3NF), etc. Each normal form has a set of rules that need to be satisfied to ensure data integrity and eliminate data anomalies, such as update, insertion, and deletion anomalies.
Indexing:
Indexing is a technique used to improve the efficiency of data retrieval operations in a database. It involves creating an index on one or more columns of a table, which allows the database system to locate specific rows quickly using the indexed column(s). Indexes are typically implemented as B-trees
and provide a faster search mechanism by reducing the number of disk I/O operations required to locate data. Indexes should be carefully designed and maintained to balance the trade-off between query performance and the overhead of maintaining the index.
Database Transactions:。