Database Systems
Jan Chomicki
University at Buffalo
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Database Systems: A Comprehensive Overview, Study Guides, Projects, Research of Design of Wood Structures
An in-depth exploration of database systems, including their definition, applications, database management systems (DBMS), additional functions, data models, schema and instance concepts, DBMS languages, efficient database access, levels of abstraction, query optimization, transactions, and major DBMS components. both relational and XML data models, and discusses the roles of query processors, transactional storage managers, and client communications managers.
Typology: Study Guides, Projects, Research
2021/2022
1 / 50
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download Database Systems: A Comprehensive Overview and more Study Guides, Projects, Research Design of Wood Structures in PDF only on Docsity!
Database Systems
Jan Chomicki
University at Buffalo
Plan of the course
1 Database Management Systems
2 Relational data model
3 Indexing
4 Query processing and optimization
5 Database design
6 Selected issues in contemporary DBMS
7 Transaction processing
What is a database
Database
- (^) a computer representation of the information needed for an application
- (^) persistent, long-lived
- (^) typically shared by many users and programs
What is a database
Database
- (^) a computer representation of the information needed for an application
- (^) persistent, long-lived
- (^) typically shared by many users and programs
Example applications
- e-commerce
- human resources, payroll
- (^) medical records
- (^) content management
- (^) public utilities and services
Database management system (DBMS)
DBMS
- a software system that makes it possible to build, modify and efficiently access large databases
- (^) supports one or more data models
- (^) supports multiple languages and interfaces for data definition, manipulation, and querying
- (^) application-independent
Database management system (DBMS)
DBMS
- a software system that makes it possible to build, modify and efficiently access large databases
- (^) supports one or more data models
- (^) supports multiple languages and interfaces for data definition, manipulation, and querying
- (^) application-independent
Additional DBMS functions
- (^) integrity maintenance
- (^) concurrency control
- resiliency
- access control
- meta-data
- support for distribution, heterogeneity, multimedia, Web access,...
Common data model
Data model
- (^) a view of data shared by the programs and the users interacting with a database
- (^) a mathematical abstraction
- (^) supported by the DBMS
Common data model
Data model
- (^) a view of data shared by the programs and the users interacting with a database
- (^) a mathematical abstraction
- (^) supported by the DBMS
Basic data model constructs
Relational Relations Object-oriented Objects, classes, attributes,... XML Labelled trees Graph Nodes, edges NoSQL Key-value pairs
Schema vs. instance
Schema
- captures and describes the structure of the data
- time-independent
Schema vs. instance
Schema
- captures and describes the structure of the data
- time-independent
FLIGHT
NUMBER AIRLINE
Schema vs. instance
Schema
- captures and describes the structure of the data
- time-independent
FLIGHT
NUMBER AIRLINE
Instance
- (^) captures the current state of the data
- (^) time-dependent
- only one exists at any given time
FLIGHT
NUMBER AIRLINE
72 Delta 97 Delta 1210 United
Relational data model
Relational data model
Schema concepts
- (^) relation schemas
- attributes
- integrity constraints
- views, triggers, procedures,...
Instance concepts
- (^) relation instances
- (^) tuples
- (^) attribute values