Question Answer
1. What is a database? An organized collection of structured
data stored electronically, managed by
a database management system
(DBMS).
2. What is a DBMS? Database Management System –
software that creates, reads, updates,
and deletes data in a database (e.g.,
MySQL, Oracle, SQL Server,
PostgreSQL).
3. What is data? Raw, unprocessed facts and figures
stored in a database.
4. What is information? Processed, organized, or structured
data that has meaning and context.
5. What is a flat file A simple database stored as a single
database? table/file with no relationships, often a
spreadsheet or CSV.
6. What is a relational A database that stores data in tables
database? (relations) and uses keys to establish
relationships between tables.
7. What does CRUD stand Create, Read, Update, Delete – the
for? four basic operations performed on
database data.
8. What is a table in a A structured set of data organized into
relational database? rows (records) and columns
(fields/attributes).
9. What is a row in a A single record or tuple representing
database table? one instance of an entity.
, Question Answer
10. What is a column in a An attribute or field that defines a
database table? specific piece of data stored for every
record in the table.
Keys & Constraints
Question Answer
11. What is a primary key? A column (or set of columns) that
uniquely identifies each row in a table.
It must be unique and NOT NULL.
12. What is a foreign key? A column in one table that references
the primary key of another table,
establishing a relationship.
13. What is a composite key? A primary key made up of two or more
columns that together uniquely identify
a row.
14. What is a surrogate key? An artificially generated key (usually an
auto-incremented integer) with no
business meaning, used as a primary
key.
15. What is a natural key? A key derived from real-world data that
has business meaning (e.g., SSN,
email address).
16. What is a candidate key? Any column or set of columns that
could qualify as a primary key – it is
unique and NOT NULL.
17. What is an alternate key? A candidate key that was not chosen
as the primary key.
18. What is referential A rule ensuring that a foreign key value
integrity? must match an existing primary key
value in the referenced table, or be
NULL.
19. What is a UNIQUE A constraint that ensures all values in
constraint? a column (or set of columns) are
distinct across all rows.
, Question Answer
20. What is a NOT NULL A constraint that prevents NULL values
constraint? from being stored in a column.
21. What is a CHECK A constraint that limits the values
constraint? allowed in a column based on a
Boolean expression.
22. What is a DEFAULT A constraint that automatically assigns
constraint? a predefined value to a column when
no value is provided during INSERT.
Normalization
Question Answer
23. What is normalization? The process of organizing a database
to reduce data redundancy and
improve data integrity by applying
normal forms.
24. What is data The unnecessary repetition of data in a
redundancy? database, which wastes storage and
can lead to anomalies.
25. What are update Problems that occur when data is
anomalies? stored redundantly; includes insertion,
deletion, and update anomalies.
26. What is First Normal A table is in 1NF if it has a primary key,
Form (1NF)? each column contains atomic
(indivisible) values, and there are no
repeating groups.
27. What does 'atomic value' Each cell holds a single, indivisible
mean in 1NF? value – no lists or sets within a single
column.
28. What is Second Normal A table is in 2NF if it is in 1NF and
Form (2NF)? every non-key attribute is fully
functionally dependent on the entire
primary key (no partial dependencies).
1. What is a database? An organized collection of structured
data stored electronically, managed by
a database management system
(DBMS).
2. What is a DBMS? Database Management System –
software that creates, reads, updates,
and deletes data in a database (e.g.,
MySQL, Oracle, SQL Server,
PostgreSQL).
3. What is data? Raw, unprocessed facts and figures
stored in a database.
4. What is information? Processed, organized, or structured
data that has meaning and context.
5. What is a flat file A simple database stored as a single
database? table/file with no relationships, often a
spreadsheet or CSV.
6. What is a relational A database that stores data in tables
database? (relations) and uses keys to establish
relationships between tables.
7. What does CRUD stand Create, Read, Update, Delete – the
for? four basic operations performed on
database data.
8. What is a table in a A structured set of data organized into
relational database? rows (records) and columns
(fields/attributes).
9. What is a row in a A single record or tuple representing
database table? one instance of an entity.
, Question Answer
10. What is a column in a An attribute or field that defines a
database table? specific piece of data stored for every
record in the table.
Keys & Constraints
Question Answer
11. What is a primary key? A column (or set of columns) that
uniquely identifies each row in a table.
It must be unique and NOT NULL.
12. What is a foreign key? A column in one table that references
the primary key of another table,
establishing a relationship.
13. What is a composite key? A primary key made up of two or more
columns that together uniquely identify
a row.
14. What is a surrogate key? An artificially generated key (usually an
auto-incremented integer) with no
business meaning, used as a primary
key.
15. What is a natural key? A key derived from real-world data that
has business meaning (e.g., SSN,
email address).
16. What is a candidate key? Any column or set of columns that
could qualify as a primary key – it is
unique and NOT NULL.
17. What is an alternate key? A candidate key that was not chosen
as the primary key.
18. What is referential A rule ensuring that a foreign key value
integrity? must match an existing primary key
value in the referenced table, or be
NULL.
19. What is a UNIQUE A constraint that ensures all values in
constraint? a column (or set of columns) are
distinct across all rows.
, Question Answer
20. What is a NOT NULL A constraint that prevents NULL values
constraint? from being stored in a column.
21. What is a CHECK A constraint that limits the values
constraint? allowed in a column based on a
Boolean expression.
22. What is a DEFAULT A constraint that automatically assigns
constraint? a predefined value to a column when
no value is provided during INSERT.
Normalization
Question Answer
23. What is normalization? The process of organizing a database
to reduce data redundancy and
improve data integrity by applying
normal forms.
24. What is data The unnecessary repetition of data in a
redundancy? database, which wastes storage and
can lead to anomalies.
25. What are update Problems that occur when data is
anomalies? stored redundantly; includes insertion,
deletion, and update anomalies.
26. What is First Normal A table is in 1NF if it has a primary key,
Form (1NF)? each column contains atomic
(indivisible) values, and there are no
repeating groups.
27. What does 'atomic value' Each cell holds a single, indivisible
mean in 1NF? value – no lists or sets within a single
column.
28. What is Second Normal A table is in 2NF if it is in 1NF and
Form (2NF)? every non-key attribute is fully
functionally dependent on the entire
primary key (no partial dependencies).
