101. What is a temporal database?
- a) A database that tracks time-varying data with built-in time support
- b) A database optimized for time-series data only
- c) A temporary in-memory database
- d) A database that automatically deletes old records
Answer: A - Temporal databases manage data with temporal dimensions (valid-time and transaction-time).
102. Which SQL standard introduced temporal features?
- a) SQL:2011
- b) SQL:1999
- c) SQL:2003
- d) SQL:2008
Answer: A - SQL:2011 added SYSTEM_VERSIONING and application-time period support.
103. What is a graph database optimized for?
- a) Storing and querying interconnected data with nodes and relationships
- b) Graphical data visualization
- c) Storing images and multimedia
- d) Generating statistical graphs
Answer: A - Graph databases excel at traversing complex relationships (e.g., social networks, recommendation systems).
104. Which query language is used in Neo4j?
- a) Cypher
- b) Gremlin
- c) GraphQL
- d) SPARQL
Answer: A - Neo4j uses Cypher, a declarative graph query language.
105. What is columnar storage in databases?
- a) Storing data by columns rather than rows for analytical queries
- b) A type of vertical partitioning
- c) A backup storage format
- d) A method to encrypt columns
Answer: A - Columnar storage improves compression and speeds up aggregate queries (used in Redshift, BigQuery).
106. What is the purpose of the SQL SYSTEM_TIME period?
- a) To track when data was stored in the database (transaction-time)
- b) To measure query execution time
- c) To schedule database maintenance
- d) To record system uptime
Answer: A - SYSTEM_TIME captures when data became current in the database (as opposed to application-time).
107. Which of the following is NOT a graph database?
- a) Neo4j
- b) Amazon Neptune
- c) ArangoDB
- d) MongoDB
Answer: D - MongoDB is a document database, though it can model graph-like structures.
108. What is a property graph model?
- a) A graph structure where nodes and relationships can have properties
- b) A database for real estate data
- c) A method to index graph properties
- d) A visualization technique
Answer: A - Property graphs allow key-value pairs on both nodes (vertices) and edges (relationships).
109. What is the purpose of the SQL VALIDTIME clause?
- a) To query data as it appeared at a specific application-time
- b) To validate time formats
- c) To check database uptime
- d) To measure query performance
Answer: A - VALIDTIME (in temporal SQL) filters data based on application-time periods.
110. What is a hypertable in time-series databases?
- a) A virtual table that automatically partitions data by time
- b) A table with extra time columns
- c) A compressed historical data table
- d) A wide table with many columns
Answer: A - Hypertables (e.g., in TimescaleDB) manage time-series data partitioning transparently.
111. Which of the following is a RDF query language?
- a) SPARQL
- b) Cypher
- c) Gremlin
- d) GraphQL
Answer: A - SPARQL queries semantic web data stored as RDF triples.
112. What is the purpose of the SQL PERIOD FOR clause?
- a) To define temporal periods in temporal tables
- b) To specify report generation periods
- c) To limit backup retention periods
- d) To define maintenance windows
Answer: A - PERIOD FOR declares valid-time or transaction-time periods in SQL:2011 temporal tables.
113. What is a triple store in graph databases?
- a) A database that stores subject-predicate-object triples
- b) A backup with three copies
- c) A three-column table
- d) A type of index
Answer: A - Triple stores specialize in RDF data (e.g., "Alice-knows-Bob").
114. What is the difference between valid-time and transaction-time?
- a) Valid-time is when data was true in reality, transaction-time is when it was recorded
- b) Valid-time tracks transactions, transaction-time tracks business validity
- c) They are synonyms
- d) Valid-time is for applications, transaction-time is for backups
Answer: A - Valid-time represents the real-world time period, transaction-time the database's view timeline.
115. Which algorithm is commonly used for graph pathfinding?
- a) Dijkstra's algorithm
- b) Bubble sort
- c) Consistent hashing
- d) B-tree traversal
Answer: A - Dijkstra's finds shortest paths between nodes in weighted graphs.
116. What is temporal projection in queries?
- a) Retrieving data as it appeared at a past time
- b) Forecasting future database states
- c) Estimating query execution time
- d) A visualization technique
Answer: A - Temporal projection enables "time travel" queries on historical data.
117. What is a graph database index-free adjacency?
- a) Direct pointer-based navigation between nodes without index lookups
- b) A graph without indexes
- c) A special adjacency matrix
- d) An optimization for isolated nodes
Answer: A - Native graph databases traverse relationships physically, avoiding index hops.
118. What is the purpose of the SQL SEQUENCE data type?
- a) To generate ordered numeric values
- b) To store DNA sequences
- c) To track query execution order
- d) To implement queues
Answer: A - SEQUENCE objects generate unique numbers (often for surrogate keys).
119. What is a graph database's advantage for fraud detection?
- a) Efficiently traversing relationships to find suspicious patterns
- b) Better storage of financial amounts
- c) Faster aggregation of totals
- d) Built-in fraud detection algorithms
Answer: A - Graph databases excel at pattern matching across relationships (e.g., detecting rings).
120. What is temporal normalization?
- a) Structuring temporal data to minimize redundancy while preserving time semantics
- b) Converting all timestamps to UTC
- c) Regular database normalization with time columns
- d) A backup rotation scheme
Answer: A - Temporal normalization extends traditional normalization with time-aware constraints.