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
Distributed Databases Some of the columns of a relation are at different sites is which of the following? Data Replication Vertical Partitioning Horizontal and Vertical Partitioning Horizontal Partitioning Data Replication Vertical Partitioning Horizontal and Vertical Partitioning Horizontal Partitioning 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 Asynchronous technology can result in unsatisfactorily slow response time because the distributed DBMS is spending considerable time checking that an update is accurately and completely propagated across the network. False True False True ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases The purpose of timestamping is to avoid the use of locks. 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. 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. ANSWER DOWNLOAD EXAMIANS APP
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