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 Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases. True False True False ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases The semijoin approach saves network traffic. 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. True False True False ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Which of the following is a disadvantage of replication? Each transaction may proceed without coordination across the network. Each site must have the same storage capacity. If the database fails at one site, a copy can be located at another site. Reduced network traffic Each transaction may proceed without coordination across the network. Each site must have the same storage capacity. If the database fails at one site, a copy can be located at another site. Reduced network traffic 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. 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. ANSWER DOWNLOAD EXAMIANS APP
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