MC	Which statement is NOT CORRECT?	Primary site 2PL comes down to applying the centralized Two-Phase Locking protocol in a distributed environment. 	incorrect	Even if the database contains replicated data, applying the basic 2PL protocol still suffices to guarantee serializability. 	correct	A disadvantage of Primary site 2PL is that the central lock manager may become a bottleneck.	incorrect	With distributed 2PL, every site has its own lock manager, which is responsible for managing all locking data pertaining to the fragments stored on that site. 	incorrect	
MC	With BASE transactions, conflict resolution...	always happens at the moment of writing the data.	incorrect	may be postponed until the data is actually read.	correct	
MC	Optimistic concurrency may considerably increase transaction throughput and overall data availability in a...	tightly coupled setting.	incorrect	loosely coupled setting.	correct	
MC	Which statement is NOT CORRECT?	A disadvantage of Primary site 2PL is that the central lock manager may become a bottleneck.	incorrect	Primary site 2PL comes down to applying the centralized Two-Phase Locking protocol in a distributed environment. 	incorrect	With distributed 2PL, every site has its own lock manager, which is responsible for managing all locking data pertaining to the fragments stored on that site. 	incorrect	Even if the database contains replicated data, applying the basic 2PL protocol still suffices to guarantee serializability. 	correct	
MC	A schedule in 2PL is deadlock free if...	the local wait-for graph contains only a limited number of cycles.	incorrect	both the local and global wait-for graphs contain no cycles.	correct	the local wait-for graphs contain no cycles.	incorrect	the global wait-for graph contains only a limited number of cycles.	incorrect	
MC	With horizontal fragmentation...	each fragment consists of a subset of the columns of the global data set.	incorrect	each fragment consists of rows that satisfy a certain query predicate.	correct	
MC	Which statement is NOT CORRECT?	Primary site 2PL comes down to applying the centralized Two-Phase Locking protocol in a distributed environment. 	incorrect	With distributed 2PL, every site has its own lock manager, which is responsible for managing all locking data pertaining to the fragments stored on that site. 	incorrect	Even if the database contains replicated data, applying the basic 2PL protocol still suffices to guarantee serializability. 	correct	A disadvantage of Primary site 2PL is that the central lock manager may become a bottleneck.	incorrect	
MC	With BASE transactions, conflict resolution...	always happens at the moment of writing the data.	incorrect	may be postponed until the data is actually read.	correct	
MC	Which statement is NOT CORRECT?	Even if the database contains replicated data, applying the basic 2PL protocol still suffices to guarantee serializability. 	correct	With distributed 2PL, every site has its own lock manager, which is responsible for managing all locking data pertaining to the fragments stored on that site. 	incorrect	Primary site 2PL comes down to applying the centralized Two-Phase Locking protocol in a distributed environment. 	incorrect	A disadvantage of Primary site 2PL is that the central lock manager may become a bottleneck.	incorrect	
MC	With BASE transactions, conflict resolution...	always happens at the moment of writing the data.	incorrect	may be postponed until the data is actually read.	correct