DAT 102 Module 1

D A T 102 Data (Datum Plural) : • Stored things (objects, events) • can be structured (numbers, dates, texts) or unstructured c videos, images, sounds) Database: • Organized collection of related data Information: • Processed data that adds meaning to the data • Adds insight & increases knowledge of user Metadata: • Describes your data elements • usually a list of attributes & values A database is an organized collection of related date. OR Databases are collections of data that are centrally stared. Databases are a solution to storing data without the use of specific files. It is akin to a central Administrative Assistant that manages the file system for everyone in the company. Requests for data all go through one source. Requests for data updates all go through one source & are applied to only the records that are affected. Each database is made up of one or more table(s); which are made up of columns (fields) & rows (records). Each Coleman represents a single piece of data & has specific attributes (metadata). Metadata; column name, data type, data length (characters) & data range (values that are valid; maximum & minimum). Each row represents a collection of data for one entity or instance of the a "thing" the data is about (name, d.o.b, etc.) Relational databases are database systems that have related entities. It's primary purpose is to reduce data duplication. A single database can be accessed by many different applications; spreadstreets, custom apps, commercial apps. Similar to out central Administrative Assistant analogy, a database has a "Manager" that all requests must go through. I.e a Database Management System (DBMS).

A DBMS is an appor service that is constantly running which queues data requests and communicates with the central database to store or pull data. Some examples: IBM DB2/DB400; used on IBM mainframes, Microsoft Access (MS's desktop based), Microsoft SQL Server (MS's server based), Oracle MySQL a Oracle DB (object oriented), etc.