08 sip database
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The document defines key concepts related to file organization and database management systems. It discusses the hierarchy of data from bits to files and databases. Issues with traditional file processing like data redundancy, poor security, and lack of data sharing are covered. The benefits of a database management system in centralizing data, minimizing redundancy, and improving security and data sharing are summarized. Relational database concepts like entities, attributes, keys, records, and tables are defined. Common database operations like select, join, and project are also outlined.
![Rainer & Cegielski, 3/e, Wiley.
Edited & revised by Zhang4-11
DBMS – Database Management Systems
It is a software used to
1. create,
2. store,
3. organize,
4. update, and
5. retrieve
data, from a single database or several
databases
[in a desirable arrangement/format, that
can be specified by the users in an easy
way]](https://image.slidesharecdn.com/08sipdatabase-130925120846-phpapp02/85/08-sip-database-11-320.jpg)
08 sip database
- 2. File Organization Terms and Concepts Bit: Smallest unit of data; binary digit (0,1) Byte: Group of bits that represents a single character, can be a letter, number, or another symbol Field: Grouping of characters into a word, group of word or complete number (such as person name or age)
- 3. Record: Group of related fields, such as student name, course taken, date, and grade File: Group of records of same type Database: Group of related files
- 4. Data Hierarchy in a Computer System Low High
- 5. Data redundancy Poor security Lack of data sharing and availability Masalah dalam Lingkungan File Tradisional
- 7. Data redundancy: duplicate data in multiple data files so that the same data are stored in more than place or location. Occure when different groups in an organization independently collect the same pice of data and sore it independently of each other. Lead to data inconsistency and waste storage resource
- 8. Poor of security Because there is little control of data management, who can access or disseminate information
- 9. Lack of data sharing and availability Information can’t flow freely across different functional areas or different part of the organization
- 10. Rainer & Cegielski, 3/e, Wiley. Edited & revised by Zhang4-10 Jessup&Valacich: Database – a collection of related data organized in a way to facilitate data searches Laudon & Laudon: A database is A collection of data Organized to efficiently serve many applications by centralizing the data and minimizing redundant data
- 11. Rainer & Cegielski, 3/e, Wiley. Edited & revised by Zhang4-11 DBMS – Database Management Systems It is a software used to 1. create, 2. store, 3. organize, 4. update, and 5. retrieve data, from a single database or several databases [in a desirable arrangement/format, that can be specified by the users in an easy way]
- 12. Database management system (DBMS) software that permits an organization to centralize data, manage them efficiently, and provide access to the stored data by application program interface between application programs and the physical data files
- 13. Rainer & Cegielski, 3/e, Wiley. Edited & revised by Zhang 4-13 Database management system (DBMS) provides all users with access to all the data. DBMSs minimize the following problems: Data redundancy Data isolation Data inconsistency DBMSs maximize the following issues: Data security Data integrity Data independence
- 14. • Separates logical view and physical views of dataSeparates logical view and physical views of data • Logical viewLogical view: information focus on how users: information focus on how users logically access information to meet theirlogically access information to meet their particular business needsparticular business needs • Physical viewPhysical view: show how data actually organized: show how data actually organized on physical storage mediaon physical storage media
- 15. The Contemporary Database Environment
- 16. Types of Databases • Relational DBMSRelational DBMS • Hierarchical and Network DBMSHierarchical and Network DBMS • Object-Oriented DatabasesObject-Oriented Databases
- 17. Entity: Person, place, thing, transaction, or event about which information is stored Entity class: often called a table is collection of similar entity Example: A customer is an entity Primary Concept of RDBS Relational DBMS
- 18. Attribute: Description of a particular entity, also called fields or column, are characteristics or properties of an entity class Example: A CUSTOMER entity can be described by a Customer Number, First Name, Last Name, Street, City, State, Zip Code, Phone Number, Credit Card No, and Credit Card Exp
- 19. Key field: Identifier field used to retrieve, update, sort a record Record: a collection of related attributes/fields about a single entity
- 20. Key field Entities, Attributes (column, field), Key field
- 21. Rainer & Cegielski, 3/e, Wiley. Edited & revised by Zhang4-21 Entitities and Attributes (Laudon, w Zhang’s editing) Fields Value of attributes / fields 4345 02/09/01 1765 8 13.75 Records
- 22. • RDBMS DefinitionRDBMS Definition • Represents data as two-dimensional tablesRepresents data as two-dimensional tables called relationscalled relations • Relates data across tables based onRelates data across tables based on common data elementcommon data element • Examples: DB2, Oracle, MS SQL ServerExamples: DB2, Oracle, MS SQL Server
- 24. Three Basic Operations in a RDBMS • Select:Select: Creates subset of rows that meet specificCreates subset of rows that meet specific criteriacriteria • Join:Join: Combines relational tables to provide usersCombines relational tables to provide users with informationwith information • Project:Project: Enables users to create new tablesEnables users to create new tables containing only relevant informationcontaining only relevant information
- 25. Three Basic Operations in a Relational Database
- 26. A row in a relation has the following properties: Only one value at the intersection of a column and row - a relation does not allow multi-valued attributes Uniqueness - there are no duplicate rows in a relation
- 27. Key field: Identifier field used to retrieve (re-search), update, sort a record Primary key - a field (or group of fields) that uniquely identifies a given entity in a table Foreign key - a primary key of one table that appears as an attribute in another file and acts to provide a logical relationship between the two files
- 28. • Primary Key – A unique primary key makes it possible to uniquely identify every row in a table – Primary key are provide way of distinguishing each entity in a table – A primary key should never change and cannot duplicated • Ex.: customer number
- 29. Foreign Key When a table contains a column that is the same as the primary key of a table, the column is called a foreign key Foreign key - a primary key of one table that appears as an attribute in another file and acts to provide a logical relationship between the two files Ex.: item number
- 30. The use of identifiers represent relationships between entities
- 31. Hierarchical DBMSHierarchical DBMS • One of type DBMSOne of type DBMS • Organizes data in a tree-like structureOrganizes data in a tree-like structure • Supports one-to-many parent-childSupports one-to-many parent-child relationshipsrelationships
Editor's Notes
- #14: Data redundancy : The same data are stored in many places. Data isolation : Applications cannot access data associated with other applications. Data inconsistency : Various copies of the data do not agree.