Databases and Information Management Chapter 6

Outline Database Relational Database Database Management System (DBMS) Structured Query Language Data Warehouse Data Mining Database Data Quality Requirements Data/Information policy (Information Management) Databases Information Systems for Management 2

Database Database: Collection of data that are organized in some way (e.g., in tables). Examples: Databases linked to Bonjour Quebec Website (book) Database in UofM’s student support systems Any department in firms. Demo… Databases Information Systems for Management 3

Relational Database The data storage for a Transaction Processing System (TPS). Adding reports to a database creates an MIS/Reporting System. Data (text, numbers, currency, time) are organized in tables (“relations”) Table = Collection of columns and rows. Column = Attribute (e.g., customer number) Row = Set of attributes (customer number + name + …) Each row identified by an attribute that must have a unique value in each row  key attribute (primary key, key) Databases Information Systems for Management 4

Relational Database – key & foreign key Tables linked via keys & foreign keys Databases Information Systems for Management 5

Database Management System (DBMS) Software for creating database, storing, retrieving and overall management of data (e.g., Microsoft Access) DBMS Components (some): Search engine – runs SQL queries against a database Report writer – usually uses queries to create reports for users Data dictionary - defines each data attribute (storage, text/numeric or other data type) Access management (who accesses what data) Security functions (recovery after system crash) Databases Information Systems for Management 6 D B M S Input forms Reports Database TPS or MIS (when Reports included)

Databases Information Systems for Management 7 Structured Query Language (SQL) Syntax and rules (commands) for searching relational databases. Can also be used for entering and changing data, and other tasks. Easier to learn than programming languages SQL Query: Select lists desired columns from desired table(s) From identifies tables/views from which to select columns Where are conditions for selecting specific records & for joining multiple tables (in older versions of SQL) Databases Information Systems for Management 7

Search Data with SQL Example SELECT Part.Part_Name, Supplier.Supplier_Name, Supplier.Supplier_Address FROM Part, Supplier WHERE Part.Supplier_Number=Supplier.Supplier_Number AND Part_Number=137 OR Part_Number=152 Output: A list with names of parts tracked under numbers 137 and 152 (keys), along with supplier names and addresses Data is stored in tables Party and Supplier, which are linked via the Supplier_Number (key in Supplier table, and foreign key in Part table) Access provides a facility for easy search without writing SQL. Databases Information Systems for Management 8

Data Warehouses Databases Information Systems for Management 9 Data warehouse (DW) Consolidates & stores data from operational databases (TPSs) Used with ERP systems Differently organized data than in a relational database Reports pulled out from more complex data (enterprise level) Cubes built from for querying at user’s will (ad hoc query)

Data Mining Analysis of data in data warehouses to find patterns/rules to aid in decision making Data Mining software specialized for searching for patterns in DW Patterns: Clusters (e.g., customer groups – market segments) Associations (e.g., what products are likely to be purchased together – video player & TV set) Databases Information Systems for Management 10

Data/Information Policy – Information Management Data/Information policy: Rules governing data acquisition, ownership, access privileges, quality of data in databases, compliance with law Data quality: Consistency (e.g., customer name) Reduction of redundancy (quality audits and data cleansing) General data quality requirements mentioned before also apply (accuracy, currency, completeness, relevance, cost- effectiveness) Databases Information Systems for Management 11