1. Chapter 1 In-lab Quiz Next week
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

2. Structural and Data Dependence
Structural dependence
Access to a file depends on its structure
Data dependence
Changes in the data storage characteristics without affecting the application program’s ability to access the data
Logical data format
How the human being views the data
Physical data format
How the computer “sees” the data
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

3. Field Definitions and Naming Conventions
Flexible record definition anticipates reporting requirements by breaking up fields into their component parts
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

4. Field Definitions and Naming Conventions (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

5. Data Redundancy Data redundancy results in data inconsistency
Different and conflicting versions of the same data appear in different places
Errors more likely to occur when complex entries are made in several different files and/or recur frequently in one or more files
Data anomalies develop when required changes in redundant data are not made successfully
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

6. Data Anomalies Types of data anomalies: Update anomalies
Occur when changes must be made to existing records
Insertion anomalies
Occur when entering new records
Deletion anomalies
Occur when deleting records
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

7. The Database System Environment
Database system is composed of five main parts:
Hardware
Software
Operating system software
DBMS software
Application programs and utility software
People
Procedures
Data
ASK FOR PARTICIPATION
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

8. The Database System Environment (continued)
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

9. DBMS Functions Manage DB structure and controls access
Share data among multiple users
Make data management more efficient and effective
Integrated view of organization’s operations
Promotes data consistency and integrity
Quick answers to ad hoc queries
Security
Last time – DBMS functions:
INTEGRITY – data must be Accurate, relevant, and timely
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

10. DBMS Functions
DBMS performs functions that guarantee integrity and consistency of data
Data dictionary management
defines data elements and their relationships
Data storage management
stores data and related data entry forms, report definitions, etc.
Data dictionary – filed names, definitions, relationships,
i.e. Phone number in customer file and in order file
Data storage management with Oracle: form and report creation
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

11. DBMS Functions (continued)
Data transformation and presentation
translates logical requests into commands to physically locate and retrieve the requested data
Security management
enforces user security and data privacy within database
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

12. DBMS Functions (continued)
Multiuser access control
uses sophisticated algorithms to ensure multiple users can access the database concurrently without compromising the integrity of the database
Backup and recovery management
provides backup and data recovery procedures
Data integrity management
promotes and enforces integrity rules
INTEGRITY – relationships created, validity checks (numeric, char, length, postal code), domain checks,
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

13. DBMS Functions (continued)
Database access languages and application programming interfaces
provide data access through a query language
Database communication interfaces
allow database to accept end-user requests via multiple, different network environments
Access language: SQL, structured, not procedural, user defines what to do not how to do it
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

14. How many records does the file contain?
How many fields are there per record?
What problem would you encounter if you wanted to produce a listing by city? How would you solve this problem by altering the file structure?
If you wanted to produce a listing of the file contents by last name, area code, city, state, or zip code, how would you alter the file structure?
What data redundancies do you detect, and how could these redundancies lead to anomalies?
5. B. Parker occurs three times, changes must be made three times…project managed by one manager but manager can manager several projects (1:M)
If B Parker does not manager one project what happens???
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel

15. Identify and discuss the serious data redundancy problems.
Looking at the EMP_NAME and EMP_PHONE contents, what change(s) would you recommend?
Identify the different data sources.
What new files should you create to help eliminate the data redundancies?
Charge for job code EE changes from 85 to 95$.
employee June H. Sattlemeier is deleted from the file, you also lose information about the existence of her JOB_CODE = EE, its hourly charge of $85.00, and the PROJ_HOURS = The loss of the PROJ_HOURS value will ultimately mean that the Coast project costs are not being charged properly, thus causing a loss of PROJ_HOURS*JOB_CHG_HOUR = 17.5 x $85.00 = $1, to the company.
Fields come from different things (entities) – project, employee, job
Database Systems: Design, Implementation, & Management, 7th Edition, Rob & Coronel