1 / 12

Database Management Systems Lecture 1 Introduction to Database Systems

Database Management Systems Lecture 1 Introduction to Database Systems. Instructor: Li Ma Department of Computer Science Texas Southern University, Houston. August, 2007. Database Systems. What is a database? A collection of a large amount of data

may-stein
Download Presentation

Database Management Systems Lecture 1 Introduction to Database Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Database Management SystemsLecture 1 Introduction to Database Systems Instructor: Li Ma Department of Computer Science Texas Southern University, Houston August, 2007

  2. Database Systems • What is a database? • A collection of a large amount of data • Persist over a long periods of time safely • Managed by DBMS • What is DBMS? • Database Management Systems • A software system • A powerful tool for creating and managing an database efficiently by Li Ma, TSU - CS346

  3. Banking System ─ An Example of DBMS • Data: information on accounts, customers, balance, interest, transaction histories, etc. • Massive: many gigabytes at minimum, more if keep history of transaction, even more if keep images of checks • Persistent: data outlives programs that operate on it by Li Ma, TSU - CS346

  4. Banking System ─ An Example of DBMS (cont) • Multi-user: many people/programs accessing same database, or even same data simultaneously • Convenient: simple commands – transfer funds, get balance, etc. • Efficient: no need to search all files for some specific operation – get balance of one account, etc. by Li Ma, TSU - CS346

  5. Database Management Systems • A DBMS provides • Persistent storage • Programming interface (for query processing) • Transaction management (for simultaneous access) • Components of a DBMS • The storage manager • The query processor • The transaction manager by Li Ma, TSU - CS346

  6. Major DBMS vendors/Products • Oracles • IBM (DB2) • Microsoft (SQL server, Access) • Informix • Sybase • All are “relational” or “object-relational” database systems by Li Ma, TSU - CS346

  7. Terminology • Data model: describes conceptual structuring of data stored in database • Ex. Data is a set of records, each with student ID, name, address, courses, photo • Ex. Data is graph where nodes represent cities, edges represent airline routes by Li Ma, TSU - CS346

  8. Terminology (cont) • Schema vs. Data • Data is actual “instance” of database, changes rapidly • Schema describes how data is to be structured, defined at set-up time, specified in one of the languages, rarely changes - metadata • Like types vs. variables in programming language by Li Ma, TSU - CS346

  9. Terminology (cont) • Data Definition Language (DDL) • Commands for setting up schema of database • Process of designing schema can be complex, may use design methodology and/or tool by Li Ma, TSU - CS346

  10. Terminology (cont) • Data Manipulation Language (DML) • Commands for manipulating data in database • Retrieve, insert, delete, modify • It is also called “query language” • Queries could be expressed in a very high-level language, which greatly increased the efficiency of database programming by Li Ma, TSU - CS346

  11. Terminology (cont) • People • DBMS implementers: build system • Database designers: set up schema, load data • Database users: query/modify data by Li Ma, TSU - CS346

  12. Content of This Course • Design of Database: how to develop a useful database? • E/R model (Chapter 2) • Relational model (Chapter 3) • Database programming: how to express queries on the database? • Relational algebra (Chapter 5) • SQL (Chapter 6&7) • Not DBMS implementation by Li Ma, TSU - CS346

More Related