test 2 Flashcards
(22 cards)
0NF–>1NF
remove repeating groups
1NF–>2NF
remove partial functional dependencies
2NF–>3NF
remove transitive dependencies
3NF→BC/NF
every determinate is a candidate key
BC/NF→4NF
remove multi-valued dependencies
4NF→5NF
remove join dependencies
three kinds of anomaly’s
insert , update and delete
DDL
"data definition language" used to create, change and destroy the logical structure that makes up the logical structure CREATE TABLE CREATE INDEX ALTER TABLE DROP TABLE RENAME TABLE DROP INDEX
DML
"data manipulation language" used for inserting and deleting data from the database SELECT UPDATE INSERT DELETE
DCL
“data controle language” is like a computer language that is used to controle security access to the database
GRANT
REVOKE
DENY
COMMIT
a statement that makes permanent all changes that have been made by current transaction
ROLLBACK
statement that undoes the changes made by the current transaction
five rules of relational notation
1) duplicate tuples
2) row column order dosent matter
3) all from the same domain
4) single value cell
5) attributes and relations unique
disjointed
subclasses have no common members
overlapping
same instance can belong to than one subclass (TA can be both a teacher and a student)
partial participation
not every member of the superclass must belong to a subclass
total participation
every member of the superclass must belong to a subclass(baby is eather a boy or girl)
generalization
moving up the hierarchy from subclass to superclass
specialization
moving down the e/r diagram superclass to subclass
functional dependencies
when one attribute uniquely determines another
A–>B
keep in mind the inverse is not true B does not determen A
fully functional dependency
when you have a functional dependence that cannot be reduced anymore
transitive dependencies
when there is an indirect relationship that causes a functional dependency
A–>C is true because
A–>B and B–>C are true
