Databases

Question 1

RELATIONAL DATABASES

Answer 1

view and logical level represent data as relations/tables

Question 2

SQL

Answer 2

Structured Query Language- a declarative data manipulation language

Question 3

IMPERATIVE LANGUAGE

Answer 3

explicit control
implicit logic

Question 4

DECLARATIVE LANGUAGE

Answer 4

implicit control
explicit logic

Question 5

Examples of declarative languages:

Answer 5

logic programming
functional programming
markup language

Question 6

ACID properties

Answer 6

atomicity-transcation is either comitted or aborted
consistency-db remains in a consistent state where integrity constraints hold
isolation-multiple users can modify a database without seeing eachothers changes
durability-data is consistent regardless of disk crashes

Question 7

TRANSACTION

Answer 7

a sequence of operations that preform a certain logical function

Question 8

ER model

Answer 8

entity relationships model

Question 9

UML class diagram

Answer 9

entities/relationships–>classes/associations

Question 10

ANSI SPARC Architecture

Answer 10

ensures logical and physical data independence

Question 11

view level

Answer 11

application programs hide details of data types; hide info for privacy and security

Question 12

logical level also called…

Answer 12

conceptual schema

Question 13

logical level

Answer 13

describes data stored in a db and relationships between the data

Question 14

physical level

Answer 14

how the data is stored: disk pages, byte layout, record order, index structures

Question 15

In a pure relational model, data is a set of…

Answer 15

tuples

Question 16

Database Schema=

Answer 16

relations+constraints

Question 17

algorithm=
(Kowalski)

Answer 17

logic+control

Question 18

types of constraints:

Answer 18

data types
column constraints
check constraints