Distributed Databases Storing a separate copy of the database at multiple locations is which of the following? Data Replication Vertical Partitioning Horizontal Partitioning Horizontal and Vertical Partitioning Data Replication Vertical Partitioning Horizontal Partitioning Horizontal and Vertical Partitioning ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Which of the following is a disadvantage of replication? Each transaction may proceed without coordination across the network. Reduced network traffic If the database fails at one site, a copy can be located at another site. Each site must have the same storage capacity. Each transaction may proceed without coordination across the network. Reduced network traffic If the database fails at one site, a copy can be located at another site. Each site must have the same storage capacity. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex. 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 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
Distributed Databases A semijoin is which of the following? 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. 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. ANSWER DOWNLOAD EXAMIANS APP
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