Distributed Databases Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment. True False True False ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Which of the following is a disadvantage of replication? If the database fails at one site, a copy can be located at another site. Each transaction may proceed without coordination across the network. Reduced network traffic Each site must have the same storage capacity. If the database fails at one site, a copy can be located at another site. Each transaction may proceed without coordination across the network. Reduced network traffic Each site must have the same storage capacity. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned. False True False True ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Synchronization for pull replication is less disruptive and occurs only when needed by each site, not when a central master site thinks it is best to update. False True False True ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases With asynchronous technology, if any copy of a data item is updated anywhere on the network, the same update is immediately applied to all other copies or it is aborted. True False True False ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases A transaction manager is which of the following? Maintains before and after database images All of these Maintains appropriate concurrency control Maintains a log of transactions Maintains before and after database images All of these Maintains appropriate concurrency control Maintains a log of transactions ANSWER DOWNLOAD EXAMIANS APP
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