answers)
SQL correct answers structured query language, the most widely used language for creating,
manipulating, and querying relational DBMSs.
relation correct answers a table with rows and columns; consists of a relation schema and a
relation instance
integrity constraint correct answers condition specified on a database schema and restricts the
data that can be stored in an instance of the database
relation instance correct answers a table; satisfies the domain constraints in the relation schema
relation schema correct answers describes the column heads for the table (column or attribute)
students(sid: string, name: string) correct answers the field named sid has a domain named
string. The set of values associated with domain string is the set of all character strings
tuples (records) correct answers an instance of a relation (rows); each tuple is unique and has the
same number of fields as the relation schema
domain constraints correct answers specify an important condition that we want each instance of
the relation to satisfy: values must come from a domain associated with that column
degree (arity) correct answers the number of fields
cardinality correct answers the number of tuples (rows)
relational database correct answers collection of relations with distinct relation names
relational database schema correct answers collection of schemas for the relations in the
database
instance of a relational database correct answers a collection of relation instances, one per
relation schema in the database schema; each relation instance must satisfy the domain
constraints in its schema
Data Definition Language (DDL) correct answers subset of SQL that supports the creation,
deletion, and modification of tables
CREATE TABLE correct answers statement used to define a new table
ex:
CREATE TABLE Students (sid CHAR(20),
name CHAR(20),