MIS 180 Essay

Submitted By edgarloblas
Words: 1401
Pages: 6

INTRO:
•Online transaction processing (OLTP) gathering and processing information and updating existing information to reflect the processed information
—Supports operational processing
—Sales orders, accounts receivable, etc
—Supported by operational databases & DBMSs

•Online analytical processing (OLAP) manipulation of information to support decision making
—Helps build business intelligence
—Supported by data warehouses and data-mining tools RELATIONAL DATABASE MODEL:
žDatabase – collection of information that you organize and access according to the logical structure of the information
žRelational database – series of logically related two-dimensional tables or files for storing information
—Relation = table = file
—Most popular database model
DATABASE- CREATED WITH LOGICAL STRUCTURES
žData dictionary – contains the logical structure for the information in a database
žPrimary key – field (or group of fields) that uniquely describes each record
žForeign key – primary key of one file that appears in another file

žIntegrity constraints – rules that help ensure the quality of information
žData dictionary, for example, defines type of information – numeric, date, and so on
žForeign keys – must be found as primary keys in another file
—E.G., a Customer Number in the Order Table must also be present in the Customer Table
Database management system (DBMS) helps you specify the logical requirements for a database and access and use the information in a database

5 CONCEPTS OF DBMS
1.DBMS engine
2.Data definition subsystem
3.Data manipulation subsystem
4.Application generation subsystem
5.Data administration subsystem

DBMS ENGINE:
•DBMS engine – accepts logical requests from other DBMS subsystems, converts them into the physical equivalents, and access the database and data dictionary on a storage device
•Physical view – how information is physically arranged, stored, and accessed on a storage device
•Logical view – how you need to arrange and access information to meet your needs

DATA DEFINITION SUBSYSTEM
žData definition subsystem – helps you create and maintain the data dictionary and structure of the files in a database
žThe data dictionary helps you define…
—Field names
—Data types (numeric, etc)
—Form (do you need an area code)
—Default value
—Is an entry required, etc

DATA MANIPULATION SUBSYSTEM:
žData manipulation subsystem – helps you add, change, and delete information in a database and query it to find valuable information
žMost often your primary interface
žIncludes views, report generators, query-by-example tools, and structured query language

VIEW
žView – allows you to see the contents of a database file, make changes, and query it to find information

REPORT GENERATOR
žReport generator – helps you quickly define formats of reports and what information you want to see in a report

QUERY-BY-EXAMPLE TOO
žQBE tool – helps you graphically design the answer to a question

STRUCTURED QUERY LANGUAGE
žSQL – standardized fourth-generation query language found in most DBMSs
žSentence-structure equivalent to QBE
žMostly used by IT professionals

APPLICATION GENERATION SUBSYSTEM
žApplication generation subsystem – contains facilities to help you develop transaction-intensive applications
žMainly used by IT professionals

DATA ADMINISTRATION SUBSYTEM
•Data administration subsystem – helps you manage the overall database environment by providing facilities for…
—Backup and recovery
—Security management
—Query optimization
—Reorganization
—Concurrency control
—Change management
žBackup and recovery – for backing up information and restarting (recovering) from a failure
—Backup – copy of information on a computer
—Recovery – process of reinstalling the backup information in the even the information was lost
žSecurity management – for CRUD access – create, read, update, and delete…