Database System Design Exam 1 questions with correct answers

Relational Database A collection of tables (relations) Doman Attribute The set of allowed values for each attribute. Atomic Attribute Values that are indivisible Database Schema The logical design of the database. Database Instance A snapshot of the data in the database at a given instant in time. Relation Schema Consists of a list of attributes and their corresponding domains. Primary Key Unique identifier that labels a certain row in a table of relational databases. Foreign Key A column in a database table containing values that are also found in some primary key column of a different table. Data Definition Language (DDL) Allows the specification of information about realtions including: 1. The schema for each relation 2. The domain of values associated with each attribute 3. Integrity contrainsts Domain Types in SQL 1. char(n) 2. varchar(n) 3. int 4. smallint 5. numeric(p,d) 6. float(n) 7. real, double precision User-Defined Types create type Dollars as numeric (12, 2) final create table department( dept_name varchar(20), building varchar(15), budget Dollars );