BITM 330 CH1

Functions of database application programs

- create and process forms - process user queries - create and process reports - execute application logic - control application

Database system

4 components: users, the database application, the database management system and the database

Modification actions

Insert, update and delete. To evaluate desig, each of these three need to be examined

self describing

Means that a description of the structure of the database is contained within the database itself. Because this is so, the contents of a database can always be determined just by looking inside the databse itself.

Enterprise class database system

Some enormous databases support international org. Such databases have hundreds of tables with millions of rows of data and suppport thousands of concurrent ussers. These databases are in use 24 hrs a day, 7 days a week

referential integrity constraints

When database mgnment enforces these rules

personal database system

a researcher might use database tech to track the results of experiments performed in a lab. Such a database might only include a few tables and each table would have at most, several hundred rows

Database

collection of related tables and other structeres

database managnment system

computer program used to create, process, and adm the database. It receives requests encoded in sql and translates those requests into actions on the database. The DBMS is a large, complicated program that is licensed from a software vendor,, comanies almost nevr write their own DBMS APP

Database

considered to be self describing collection of related tables

Relational database

contains a collection of separate tables

Metadata

data about the structure og a databse (Names of tables, names of columns, and the tables to which they belong)

NoSQL(Non realational databse)

database that doesn't like sql

concurrency

ensures that one users work doesn't inapp interfere with anothers work. This important/ complicated function

users

fourth component of a database system, employ a database app to keep track of things. they use forms to read, enter and query data and they produce reports

table

holds data about one and only one theme in most circumstances. If the table has two or more themes, we break it up into two or more tables

Relational model

leading solution-almost every commerical database is based on this

Structured query language

leading technique for data definition and manipulation. Its an international standard. Using this, you can reconstruct lists from their underlying tables; you can query for specific data conditions; you can perform computations on data in tables and you can insert, update and delete data

Null values

missing value

database app

set of one or more computer programs that serves as an intermediary between the user and the DBMS. Application programs also present data to users in the format of forms and reports. Application programs also can be acquired from software vendors, and they are frequently written in house.

WEB 2.0

the need for nonrelational applications tat arose to web 2.0. These are applications that allowed the user to create and store data that would be subsequentlty displayed on the web page