Distributed Databases Which of the following is a disadvantage of replication? Reduced network traffic Each site must have the same storage capacity. Each transaction may proceed without coordination across the network. If the database fails at one site, a copy can be located at another site. Reduced network traffic Each site must have the same storage capacity. Each transaction may proceed without coordination across the network. If the database fails at one site, a copy can be located at another site. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system. 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 a log of transactions Maintains appropriate concurrency control Maintains before and after database images All of these Maintains a log of transactions Maintains appropriate concurrency control 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. True False True False ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases A semijoin is which of the following? Only the joining attributes are sent from one site to another and then all of the rows are returned. All of the attributes are sent from one site to another and then only the required rows are returned. All of the attributes are sent from one site to another and then only the required rows are returned. Only the joining attributes are sent from one site to another and then only the required rows are returned. Only the joining attributes are sent from one site to another and then all of the rows are returned. All of the attributes are sent from one site to another and then only the required rows are returned. All of the attributes are sent from one site to another and then only the required rows are returned. Only the joining attributes are sent from one site to another and then only the required rows are returned. 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. False True False True ANSWER DOWNLOAD EXAMIANS APP
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