Distributed Databases Storing a separate copy of the database at multiple locations is which of the following? Data Replication Horizontal Partitioning Horizontal and Vertical Partitioning Vertical Partitioning Data Replication Horizontal Partitioning Horizontal and Vertical Partitioning Vertical Partitioning ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases A transaction manager is which of the following? 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 Maintains before and after database images ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Some of the columns of a relation are at different sites is which of the following? Horizontal Partitioning Data Replication Vertical Partitioning Horizontal and Vertical Partitioning Horizontal Partitioning Data Replication Vertical Partitioning Horizontal and Vertical Partitioning 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. 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. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases A distributed database can use which of the following strategies? All of these Partially or totally replicated across sites Totally centralized at one location and accessed by many sites Partitioned into segments at different sites All of these Partially or totally replicated across sites Totally centralized at one location and accessed by many sites Partitioned into segments at different sites 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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