knowledge Questions with Expertly written
solution 2024/2025
What is a determining characteristic of unstructured data? - correct answer it does not
follow a data model
What is true about flat files? - correct answer - they contain no internal hierarchical
organization
How were data retrieved before database management systems? - correct answer
sequentially from simple files
What is an attribute or group of attributes that uniquely identify a tuple in a relation? -
correct answer primary key
What is necessary for a primary key in one relation of a database to match with its
corresponding foreign key in another relation of the same database? - correct answer
a domain of values
What uniquely identifies each entity in a collection of entities but is not the primary key?
- correct answer alternate key
What is the term for a set of columns in a table that can uniquely identify any record in
that table without referring to other data? - correct answer candidate key
What happens to the original data in database indexing? - correct answer it is copied
to the index
Why are indexes created in a physical database design? - correct answer to retrieve
data directly using a pointer
, Why is an index created on a database column? - correct answer to optimize data
retrievals
Define: functional dependency - correct answer each value of a column relates to at
most one value of another column
Dependence of one column on another
What term is used to describe: a value of one particular attribute associated with a
specific single value of another attribute? - correct answer functional dependency
Rules/appearance of first normal form - correct answer - all non-key columns depend
on primary key
- each table cell contains one value
- a table with no duplicate rows
Rules/appearance of second normal form - correct answer - when all non-key columns
depend on the whole primary key
- must be in 1nf
- non-key column can not depend on just one part of a composite key - a single primary
key is automatically in 2nf
Rules/appearance of third normal form - correct answer - all non-key columns depend
only on the primary key
- tables are totally free of data redundancy
What are the 4 ways that operational and analytical databases differ? - correct answer
- volatility
- detail
- scope
- history