INFO MANAGEMENT PRELIM Flashcards
1.1 - 1.2 ONLY
Collected facts about a topic or item
Data
The result of combining, comparing and performing calculations on data
Information
a centralized and structured set of data stored on a computer system
database
Elements of a DBMS
- kernel code
- Repository of metadata
- Query language
who proposed the relational model for database systems
Dr. E.F Codd
the basis for the relational database management system (RDBMS)
Relational Database Concept
a collection of relations or two-dimensional tables.
Relational Database Concept
basic storage structure
table
one kind of data in a table, also called attributes
column
data for one table instance
also called a record
row
value found at the intersection of a row and column
field
unique identifier for each row
primary key
column that refers to a primary-key column in another table
foreign key
4 main SQL statements
- Data manipulation language (DML)
- Data definition language (DDL)
- Transaction control language (TCL)
- Data control language (DCL)
statements begin with INSERT, UPDATE, DELETE, or MERGE and are used to modify the table data by entering new rows, changing existing rows, or removing existing rows.
Data manipulation language (DML)
statements create, change, and remove data structures from the database
Keywords: CREATE, ALTER, DROP, RENAME, and TRUNCATE
Data definition language (DDL)
statements are used to manage the changes made by DML statements.
Keywords: COMMIT, ROLLBACK, and SAVEPOINT.
Transaction control language
keywords GRANT and REVOKE are used to give or remove access rights to the database and the structures within it.
Data control language (DCL)
The process of organizing attributes and tables of a relational database to minimize redundancy
Normalization
very essential function of relational databases
ensures that data is accurate and consistent
data integrity
the smallest logical storage unit of a database
Data blocks
a logical unit of database storage space
Extents
identifies the highest level relationships between different entities
Conceptual modeling
