| DBMS |
Database management system 数据库管理系统 |
| redundancy |
冗余 |
| inconsistency |
不一致 |
| access data |
存取数据 |
| Data isolation |
数据独立性 |
| Integrity problems |
完整性问题 |
| Atomicity of updates |
更新的原子性 |
| Concurrent access by multiple users |
多用户的并发访问 |
| Security problems |
安全问题 |
| Data model |
A collection of conceptual(概念上的) tools for describing data, data relationships, data semantics, and consistency constraimts. |
| Data abstraction |
Hide the complexity of data structures to represent data in the database from users through several levels of data abstraction. |
| DML |
Data Manipulation Language |
| View level |
Application programs hide details of data types. Views can also hide information (such as an employee’s salary) for security purposes. |
| DDL |
Data Definition Language 数据定义语言 |
| DML |
Data Manipulation Language |
| Procedural DML |
require a user to specify what data are needed and how to get those data. |
| Declarative DML |
without specifying how to get those data. referred to as non-procedural DMLs. |
| SQL |
nonprocedural.NOT a Turing machine equivalent language. |
