Database Technology Overview

Basic Concept 1 Database and database management system 1) database system, composed of databases, hardware, software, and personnel. 2) databases are centrally managed and stored in computers for a long time. They are a collection of organized and relevant data. 3) The software includes the operating system, database management system, and applications. 4) personnel a system analyst and Database Designer

Basic Concept 1 Database and database management system 1) database system, composed of databases, hardware, software, and personnel. 2) databases are centrally managed and stored in computers for a long time. They are a collection of organized and relevant data. 3) The software includes the operating system, database management system, and applications. 4) personnel a system analyst and Database Designer

Basic Concepts

1. Database and database management system

1) a database system consists of databases, hardware, software, and personnel.

2) databases are centrally managed and stored in computers for a long time. They are a collection of organized and relevant data.

3) The software includes the operating system, database management system, and applications.

4) Personnel

A system analyst and Database Designer

B application programmer

C. End User

D. Database Administrator

2. DBMS Functions

1) Data Definition database a structure description B integrity definition c security and confidentiality definition

2) database operation a search B insert c modify d Delete

3) database operation management a concurrency control B security check c access control d integrity check and execution e operation log organization management f Transaction Management g Automatic Recovery

4) data organization, storage, and management a includes data dictionary, user data, and access path. B. Determine the file structure and access method at the storage level. C connects data to improve the utilization of storage space.

5) database establishment and maintenance

6) Other functions

3. DBMS features

1) structured and unified database management.

2) high data independence.

3) data control function.

Security Protection of database.

B. Data Integrity.

C concurrency control.

D. fault recovery.

4. DBMS Classification

1) relational database system (RDBS)

2) Object-Oriented Database System (OODBS)

3) Object Relational Database System (ORDBS)

5. Database System Architecture

1) centralized database system

2) Client/Server Architecture

3) Parallel Database System

4) Distributed Database System

6. Three-Level schema of the database

1) concept Mode

2) External Mode

3) Internal Mode

4) Two-Level Image

Binary data model

1 concept

2. Three elements of the data model

3 E-R Model

4. Hierarchical Model

5. Mesh Model

6. Currently, the relational model is one of the most commonly used data models. In the relational model, tables are used to express the relationships between object sets and object sets.

7. object-oriented model

1) object and Object ID (OID)

2) Encapsulation

3) attributes of an object

4) Class and Class hierarchy

5) Inheritance

Three relational algebra

1. attributes and fields

2 Cartesian Product and relationship

3. concepts related to links

4. Link Type

5. Relational Database Mode

6 integrity constraints

7 relational operations

4. Introduction to Relational Database SQL

1. SQL database architecture

2. Basic Components of SQL

3. SQL data definition

4. SQL data query

5. SQL data update

6. SQL access control

7. Embedded SQL

5. Relational Database Standardization

1. function dependency

2. Standardization

3. Features of pattern decomposition and Decomposition

Six Database Control Functions

1. Transaction Management

A transaction is an operational sequence, either done or not. It is an inseparable logical unit of work.

1) SQL statements defined by transactions:

Begin transaction: Start of the TRANSACTION

COMMIT: transaction COMMIT

ROLLBACK: Transaction ROLLBACK

2) ACID)

Atomicity)

Consistency)

Isolation)

Durability)

2. database backup and recovery

1) Key Technologies of databases are establishing redundant data, that is, backing up data. The database recovery technology is how to restore the database to the correct state before the fault in a timely manner after a system failure occurs.

2) fault type:

A. Internal Faults

B. System Faults

C. Media faults

D. Computer Viruses

3) backup method

4) Recovery

5) database image

3. Concurrency Control