WGU C175/D426 DATA MANAGEMENT FOUNDATIONS
EXAM COMPLETE QUESTIONS AND 100% VERIFIED
ANSWERS (PASS GUARANTEE)
1. What is a database? A database is an organized collection of structured data
stored electronically in a computer system, designed for efficient storage,
retrieval, and management of information.
2. What is a Database Management System (DBMS)? A DBMS is software
that enables users to create, maintain, and manipulate databases. It provides an
interface between the database and end users or application programs.
3. What are the main advantages of using a database? Advantages include
data integrity, reduced data redundancy, improved data sharing, enhanced
security, better data consistency, and easier data access and maintenance.
4. What is data redundancy? Data redundancy occurs when the same piece of
data exists in multiple places within a database, leading to wasted storage space
and potential inconsistencies.
5. What is data integrity? Data integrity refers to the accuracy, consistency,
and reliability of data stored in a database throughout its lifecycle.
6. What is a flat file database? A flat file database stores data in a single table
structure, similar to a spreadsheet, with rows and columns but without
relationships to other tables.
7. What are the disadvantages of flat file databases? Disadvantages include
high data redundancy, limited scalability, difficulty in maintaining data
integrity, and inefficient data retrieval for complex queries.
8. What is a relational database? A relational database organizes data into
tables (relations) that can be linked based on common data fields, following
principles defined by E.F. Codd.
9. Who developed the relational database model? Dr. E.F. Codd developed
the relational database model in 1970 while working at IBM.
10. What is SQL? SQL (Structured Query Language) is a standardized
programming language used to manage and manipulate relational databases.
,11. What are the main components of a database system? The main
components are: hardware, software (DBMS), data, procedures, and database
users.
12. What is metadata? Metadata is "data about data" - it describes the
structure, constraints, and characteristics of data stored in a database.
13. What is a data dictionary? A data dictionary is a centralized repository
that stores metadata about database objects, including table definitions, column
types, and relationships.
14. What is database independence? Database independence means that
changes to the database structure do not require changes to application
programs that use the database.
15. What are the two types of database independence? Physical
independence (changes to physical storage don't affect logical schema) and
logical independence (changes to logical schema minimally affect applications).
16. What is a schema? A schema is the overall design or structure of a
database, defining how data is organized and how relationships among data are
handled.
17. What are the three levels of database architecture (ANSI-SPARC)?
External level (user views), conceptual level (logical structure), and internal
level (physical storage).
18. What is the external level in database architecture? The external level
represents individual user views of the database, showing only the data relevant
to specific users or applications.
19. What is the conceptual level in database architecture? The conceptual
level represents the logical structure of the entire database, including all entities,
attributes, and relationships.
20. What is the internal level in database architecture? The internal level
describes how data is physically stored in the database, including file structures
and indexing methods.
21. What is ACID in database transactions? ACID stands for Atomicity,
Consistency, Isolation, and Durability - properties that guarantee reliable
database transaction processing.
22. Explain Atomicity in ACID. Atomicity ensures that a transaction is treated
as a single, indivisible unit - either all operations complete successfully or none
do.
, 23. Explain Consistency in ACID. Consistency ensures that a transaction
brings the database from one valid state to another, maintaining all defined rules
and constraints.
24. Explain Isolation in ACID. Isolation ensures that concurrent transactions
do not interfere with each other, with each transaction appearing to execute in
isolation.
25. Explain Durability in ACID. Durability guarantees that once a transaction
is committed, its effects are permanent, even in the event of system failures.
26. What is a transaction? A transaction is a logical unit of work consisting of
one or more database operations that must be executed completely or not at all.
27. What is data independence? Data independence is the ability to modify
database schema at one level without affecting the schema at the next higher
level.
28. What are the advantages of DBMS over file systems? Advantages
include controlled redundancy, data sharing, enforced standards, improved data
security, backup and recovery, and data integrity maintenance.
29. What is concurrent access in databases? Concurrent access allows
multiple users to access and manipulate the database simultaneously without
conflicts or data corruption.
30. What is a query? A query is a request for data or information from a
database, typically written in SQL or another query language.
31. What is data abstraction? Data abstraction hides the complexity of data
storage and presents data in a simplified manner to users and applications.
32. What are the different types of database users? Database users include:
end users, application programmers, database administrators (DBAs), and
system analysts.
33. What is the role of a Database Administrator (DBA)? A DBA manages
and maintains the database system, handles security, performs backups,
optimizes performance, and ensures data integrity.
34. What is a database instance? A database instance is a specific occurrence
of a database running in memory at a particular point in time.
35. What is the difference between a database and a DBMS? A database is
the collection of data itself, while a DBMS is the software used to manage,
access, and manipulate that data.
EXAM COMPLETE QUESTIONS AND 100% VERIFIED
ANSWERS (PASS GUARANTEE)
1. What is a database? A database is an organized collection of structured data
stored electronically in a computer system, designed for efficient storage,
retrieval, and management of information.
2. What is a Database Management System (DBMS)? A DBMS is software
that enables users to create, maintain, and manipulate databases. It provides an
interface between the database and end users or application programs.
3. What are the main advantages of using a database? Advantages include
data integrity, reduced data redundancy, improved data sharing, enhanced
security, better data consistency, and easier data access and maintenance.
4. What is data redundancy? Data redundancy occurs when the same piece of
data exists in multiple places within a database, leading to wasted storage space
and potential inconsistencies.
5. What is data integrity? Data integrity refers to the accuracy, consistency,
and reliability of data stored in a database throughout its lifecycle.
6. What is a flat file database? A flat file database stores data in a single table
structure, similar to a spreadsheet, with rows and columns but without
relationships to other tables.
7. What are the disadvantages of flat file databases? Disadvantages include
high data redundancy, limited scalability, difficulty in maintaining data
integrity, and inefficient data retrieval for complex queries.
8. What is a relational database? A relational database organizes data into
tables (relations) that can be linked based on common data fields, following
principles defined by E.F. Codd.
9. Who developed the relational database model? Dr. E.F. Codd developed
the relational database model in 1970 while working at IBM.
10. What is SQL? SQL (Structured Query Language) is a standardized
programming language used to manage and manipulate relational databases.
,11. What are the main components of a database system? The main
components are: hardware, software (DBMS), data, procedures, and database
users.
12. What is metadata? Metadata is "data about data" - it describes the
structure, constraints, and characteristics of data stored in a database.
13. What is a data dictionary? A data dictionary is a centralized repository
that stores metadata about database objects, including table definitions, column
types, and relationships.
14. What is database independence? Database independence means that
changes to the database structure do not require changes to application
programs that use the database.
15. What are the two types of database independence? Physical
independence (changes to physical storage don't affect logical schema) and
logical independence (changes to logical schema minimally affect applications).
16. What is a schema? A schema is the overall design or structure of a
database, defining how data is organized and how relationships among data are
handled.
17. What are the three levels of database architecture (ANSI-SPARC)?
External level (user views), conceptual level (logical structure), and internal
level (physical storage).
18. What is the external level in database architecture? The external level
represents individual user views of the database, showing only the data relevant
to specific users or applications.
19. What is the conceptual level in database architecture? The conceptual
level represents the logical structure of the entire database, including all entities,
attributes, and relationships.
20. What is the internal level in database architecture? The internal level
describes how data is physically stored in the database, including file structures
and indexing methods.
21. What is ACID in database transactions? ACID stands for Atomicity,
Consistency, Isolation, and Durability - properties that guarantee reliable
database transaction processing.
22. Explain Atomicity in ACID. Atomicity ensures that a transaction is treated
as a single, indivisible unit - either all operations complete successfully or none
do.
, 23. Explain Consistency in ACID. Consistency ensures that a transaction
brings the database from one valid state to another, maintaining all defined rules
and constraints.
24. Explain Isolation in ACID. Isolation ensures that concurrent transactions
do not interfere with each other, with each transaction appearing to execute in
isolation.
25. Explain Durability in ACID. Durability guarantees that once a transaction
is committed, its effects are permanent, even in the event of system failures.
26. What is a transaction? A transaction is a logical unit of work consisting of
one or more database operations that must be executed completely or not at all.
27. What is data independence? Data independence is the ability to modify
database schema at one level without affecting the schema at the next higher
level.
28. What are the advantages of DBMS over file systems? Advantages
include controlled redundancy, data sharing, enforced standards, improved data
security, backup and recovery, and data integrity maintenance.
29. What is concurrent access in databases? Concurrent access allows
multiple users to access and manipulate the database simultaneously without
conflicts or data corruption.
30. What is a query? A query is a request for data or information from a
database, typically written in SQL or another query language.
31. What is data abstraction? Data abstraction hides the complexity of data
storage and presents data in a simplified manner to users and applications.
32. What are the different types of database users? Database users include:
end users, application programmers, database administrators (DBAs), and
system analysts.
33. What is the role of a Database Administrator (DBA)? A DBA manages
and maintains the database system, handles security, performs backups,
optimizes performance, and ensures data integrity.
34. What is a database instance? A database instance is a specific occurrence
of a database running in memory at a particular point in time.
35. What is the difference between a database and a DBMS? A database is
the collection of data itself, while a DBMS is the software used to manage,
access, and manipulate that data.
