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DatabasesFebruary 6 – February 10 Introduction: Business intelligence (BI) is knowledge about your customers, your competitors, your business partners, your competitive environment, and your own internal operations – that gives you the ability – that gives you the ability to make effective, important, and often strategic business decisions (p. 126). An operational database stores valuable information that forms the basis for business intelligence (p. 126). Online transactional processing (OTLP) is the gathering of input information, processing, and updating of information in an operational database. Online analytical processing (OLAP) is the manipulation of information to support decision making (p. 126). Relational Database Model:o The most popular database model is the relational database model. A relational database model is one that consists of multiple tables that they are related (p. 128).ORDER TABLEOrderNumberOrderDateCustomerNumberConcreteTypeAmount(Tons)10000 9/1/2004 1234 1 810001 9/1/2004 3456 1 310002 9/2/2004 1234 5 610003 9/3/2004 4567 2 410004 9/5/2004 3456 3 6CUTOMER TABLECustomerNumberCustomerNameCustomerPhoneCustomerAddress1234 Smelding Homes 662-329-7164 55 Smith Lane3456 Mark Akey 662-312-4589 2122 E. Biscayne4567 Triple A Homes 662-325-1560 1333 Burr RidgeCONCRETE TYPE TABLEConcrete Type Type Description1 Home foundation and walkways2 Commercial foundation3 Premier speckled4 Premier marble5 Premier shello A database table consists of rows, each of which is known as a record. A database consists of columns, each of which is known as a field.o All databases, including relational databases, have their structures defined by a data dictionary (p. 128).o A primary key is a field that uniquely describes each record. A primary key must be unique in that it uniquely identifies a record. (p 130). For example, your SSN would be the primary key in the MUW databases that uniquely identify you. Looking at the tables above, Order Number is the primary key for the ORDER TABLE, Customer Number is the primary key for the CUSTOMER TABLE, and Concrete Type is the primary key for the CONCRETE TYPE TABLE.o A foreign key is a primary key of one file that appears in another file. You can think of it as a pointer. It “points” at the primary key of another table. (p. 130). A foreign key does not have to be unique. The name of a foreign key must match the name of a primary key of another table exactly.  The values stored in a foreign key must match a value stored in the primary key of another table exactly. Customer Number is a foreign key in the ORDER TABLE (it “points” at the Customer Number primary key in the CUSTOMER TABLE). Concrete Type is also a foreign key in the ORDER TABLE (it “points” at the Concrete Type primary key in the CONCRETE TYPE TABLE).o Here’s an example. Focus on the 10002 order in the ORDER TABLE. We know that thisorder was sold to Smelding Homes (because the Customer Number 1234 points at primary key in the CUSTOMER table). We also know that the order was for six tons of Premier Shell concrete (because Concrete Type 5 points at a primary key in the CONCRETE TYPE TABLE).o Integrity constraints are rules that help ensure the quality of information. It basically prevents you from entering invalid data (p. 131). An example of an integrity constraint would be that a SSN must have 9 characters separated by dashes (NNN-NN-NNNN). If an entry does not match this format, it will be kicked out. Another example might be that a telephone number have 10 characters, separatedby dashes (NNN-NNN-NNNN). If an entry does not match this format, it will bekicked out.  Database Management System (DBMS):o A database management system (DBMS) helps you specify the logical organizations for adatabase and also retrieve and information within a database (p. 132).o A DBMS contains five important software components known as subsystems (p. 132): DBMS Engine DBMS Definition Subsystem Data manipulation subsystem Application generation subsystem Data administration systemo A DBMS Engine is the brain and processes requests from other subsystems (p. 132). The physical view of information is how information is physically arranged, stored, and accessed on some type of storage device (p. 132). The logical view of information, on the other hand, focuses on how you as a knowledge worker need to arrange and access information to meet your business needs (p. 132).o The data definition subsystem creates and maintains the data dictionary and defines the structure of the files (p. 133).o The data manipulation subsystem allows you to add, change, and delete information in a database and query it for valuable information (p. 134). View – allows you to see the contents of a database file, make whatever changes you want, perform simple sorting, and query it to find the location of specific information (p. 135). Report generator – allows you to quickly define formats and what information you want to see in a report (p. 136). Query-by-example – allows you to graphically set up a database query (p. 136).o The application generation subsystem contains facilities to help you develop transaction-intensive applications (p. 138).o The data administration subsystem helps you manage the overall database environment by providing facilities for backup and recovery, security management, etc. (p.


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MUW BU 294 - Databases

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