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 A transaction manager is which of the following? 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 Maintains before and after database images ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases The problem of concurrency control is more complex in a distributed database. True False True False ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations. False True False True 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 Data replication is favored where most process requests are read-only and where the data are relatively static. False True False True ANSWER DOWNLOAD EXAMIANS APP
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