CPS 510 MIDTERM EXAMS SET EXAM PREP
TESTED QUESTIONS 2026 GRADED A+.
⫸ Why is the schema considered "intension" and instance
"extension"? Answer: Schema = intension (it defines intent or design).
Instance = extension (it's the current content that extends the schema
with actual data).
⫸ What are the three levels of database architecture (ANSI/SPARC)?
Answer: 1. External level (user/application views) 2. Conceptual level
(logical structure of the entire database) 3. Internal level (physical
storage details).
⫸ What is the purpose of external schemas? Answer: They represent
different user views or customized subsets of the data (e.g., a student
only sees their own grades).
⫸ What is the conceptual schema? Answer: A global logical model
of the whole database that hides physical details and defines entities,
attributes, and relationships.
⫸ What is the internal schema? Answer: Describes how data is
physically stored, including file organization, indexes, and access
paths.
, ⫸ What are mappings in the three-level architecture? Answer: They
link schema levels and translate data between them
(external/conceptual and conceptual/internal), ensuring consistency
and data independence.
⫸ What is data independence? Answer: The ability to change the
schema at one level without needing to alter schemas or programs at
higher levels.
⫸ What are the two types of data independence? Answer: Logical
Data Independence (change conceptual schema without affecting
external views) and Physical Data Independence (change internal
schema without affecting conceptual schema).
⫸ Which is harder to achieve — logical or physical data
independence? Answer: Logical data independence, because
applications depend more on the logical structure of data.
⫸ Give examples of conceptual schema changes. Answer: Adding a
new attribute (e.g., "price" to PART) or creating a new table (e.g.,
PROJECT).
⫸ What are the main responsibilities of the Database Administrator
(DBA)? Answer: Design participation, enforcing security/integrity
constraints, managing backups, tuning performance, supporting users,
and maintaining metadata.
TESTED QUESTIONS 2026 GRADED A+.
⫸ Why is the schema considered "intension" and instance
"extension"? Answer: Schema = intension (it defines intent or design).
Instance = extension (it's the current content that extends the schema
with actual data).
⫸ What are the three levels of database architecture (ANSI/SPARC)?
Answer: 1. External level (user/application views) 2. Conceptual level
(logical structure of the entire database) 3. Internal level (physical
storage details).
⫸ What is the purpose of external schemas? Answer: They represent
different user views or customized subsets of the data (e.g., a student
only sees their own grades).
⫸ What is the conceptual schema? Answer: A global logical model
of the whole database that hides physical details and defines entities,
attributes, and relationships.
⫸ What is the internal schema? Answer: Describes how data is
physically stored, including file organization, indexes, and access
paths.
, ⫸ What are mappings in the three-level architecture? Answer: They
link schema levels and translate data between them
(external/conceptual and conceptual/internal), ensuring consistency
and data independence.
⫸ What is data independence? Answer: The ability to change the
schema at one level without needing to alter schemas or programs at
higher levels.
⫸ What are the two types of data independence? Answer: Logical
Data Independence (change conceptual schema without affecting
external views) and Physical Data Independence (change internal
schema without affecting conceptual schema).
⫸ Which is harder to achieve — logical or physical data
independence? Answer: Logical data independence, because
applications depend more on the logical structure of data.
⫸ Give examples of conceptual schema changes. Answer: Adding a
new attribute (e.g., "price" to PART) or creating a new table (e.g.,
PROJECT).
⫸ What are the main responsibilities of the Database Administrator
(DBA)? Answer: Design participation, enforcing security/integrity
constraints, managing backups, tuning performance, supporting users,
and maintaining metadata.
