Chapter 4 Flashcards
DBMS
Database management system
Relational database
Data from separate tables are linked together
Attribute, record and field
1) Attribute=column
2) Record=row
3) Field=individual cell
Primary Key
Attribute that can uniquely identify a specific row in a table
Foreign Key
Attribute in one table that is the primary key in another table. Links the two tables.
Rules of Relational Databases
1) Attributes must be single valued
2) Primary keys can’t be zero/empty and cannot have duplicates
Update anomaly
Changes to existing data on one table don’t update to linked tables
Insert anomaly
Unable to add a new record to the table if there is no primary key
Delete anomaly
Removing a record also removes other unintended data from the database
Data integration
Databases can be accessed by various programs, not just an AIS
Cross-functional analysis
The act of combining data from various departments
DBA
Database administrator: only one with direct access to the database
Change management
Testing changes to the database/AIS in a test environment before going live
DMBS and their associations:
1) Oracle
2) SQL
3) DB2
Oracle: Used with oracle and SAP
SQL: Used with Microsoft AIS products
DB2: Used with IBM products and custom AIS’s
SQL
Structured query language, can be used across any database
SQL: SELECT
Picks attributes
SQL: FROM
From what table will it pull data
SQL: WHERE or HAVING
Applies a filter to the data
SQL: GROUP BY
Combines like rows together
SQL: ORDER BY OR SORT BY
Organizes the output by date, alphabetically, or numerically
SQL: Excel formulas formatting
Excel formulas such as count, sum, etc start the formula without an equals sign.
SQL: JOIN
Used when 2 or more tables are used, and the same data is in both tables
REA Diagrams
Shows how databases relate and link together. Used to communicate between accounting and IT departments.
In what format do databases store information?
Table format
Risk level of database risks
High risk
