Databases and Information Management

Chapter 6

Outline

Database Relational Database Database Management System (DBMS)Structured Query LanguageData Warehouse Data Mining Database Data Quality RequirementsData/Information policy (Information Management)

DatabasesInformation 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 systemsAny department in firms. Demo…

DatabasesInformation Systems for

Management 3

Relational DatabaseThe 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)

DatabasesInformation Systems for

Management 4

Relational Database – key & foreign key

Tables linked via keys & foreign keys

DatabasesInformation 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 databaseReport writer – usually uses queries to create reports for usersData dictionary - defines each data attribute (storage, text/numeric or other data type) Access management (who accesses what data)Security functions (recovery after system crash)

DatabasesInformation Systems for

Management 6

D B M S

Input forms

Reports

DatabaseTPS or MIS (when Reports included)

DatabasesInformation 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 columnsWhere are conditions for selecting specific

records & for joining multiple tables (in older versions of SQL)

DatabasesInformation Systems for

Management 7

Search Data with SQL ExampleSELECT Part.Part_Name, Supplier.Supplier_Name,

Supplier.Supplier_AddressFROM Part, SupplierWHERE 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.

DatabasesInformation Systems for

Management 8

Data Warehouses

DatabasesInformation Systems for

Management 9

Data warehouse (DW)Consolidates & stores data from operational databases (TPSs)Used with ERP systemsDifferently organized data than in a relational databaseReports 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)

DatabasesInformation 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)

DatabasesInformation Systems for

Management 11