Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
Essence of Normalization |
every normalized relation has a single theme |
|
|
1st Normal Form |
-cells must be single valued -all entries must be of the same kind -each attribute have unique name -attribute order doesnt matter |
|
|
2nd Normal Form |
all nonkey attributes are dependent on all of the key |
|
|
3rd Normal Form |
2nd normal form and no transitive dependencies (a determines b and b determines c → don’t do this) |
|
|
Boyce -Codd Normal Form |
every determinant is a candidate key (id and email for a student) |
|
|
4th Normal Form |
bc form no multi-valued dependencies (std_id determines lists of classes you’ve taken and list of classes determine students) |
|
|
5th Normal Form |
nooooooooooo.... |
|
|
Domain/ Key Normal Form |
if every constraint on the relation is a logical consequence of the definition of keys and domains (can’t be married before you are born) |
|
|
3 Types of Anomalies |
Update, Insertion, and Deletion |
|
|
Update Anomaly |
updating one without updating another ex: person but not institution table |
|
|
Insertion Anomaly |
not having all the data necessary to insert ex: creating a conference before someone registers for it |
|
|
Deletion Anomaly |
deleting more information than desired ex: after a person dies, deleting them from the database entirely |
|
|
Why Normalize |
prevents anomalies, ensures more accurate data |
|
|
Why NOT Normalize |
decreases efficiency (due to joins) |
|
|
3 diff DBMS users |
-Conventional Users -Application Programs -DBA |
|
|
DBMS uses |
-Support the durability of the data -Allows users to create new databases -Support LARGE amounts of data over a LONG period of time -Allows users to query databases |
|
|
Logging |
the storing of information, such as queries, to another location |
|
|
3 things to connect to Oracle database |
username, password, name of database |
|
|
How Indexes make databases Faster |
don’t have to look for every value (instead, look at index to access data, which takes less time) |
|
|
How Indexes make databases Slower |
storing a lot of info and creating indexes takes up time and more space |
