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 all of the rows are returned. Only the joining 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. 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 all of the 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 appropriate concurrency control Maintains before and after database images Maintains a log of transactions All of these Maintains appropriate concurrency control Maintains before and after database images Maintains a log of transactions 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 Replication should be used when which of the following exist? The application's data can be somewhat out-of-date. All of these When transmission speeds and capacity in a network prohibit frequent refreshing of large tables. When using many nodes with different operating systems and DBMSs and database designs. The application's data can be somewhat out-of-date. All of these When transmission speeds and capacity in a network prohibit frequent refreshing of large tables. When using many nodes with different operating systems and DBMSs and database designs. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Some of the columns of a relation are at different sites is which of the following? Vertical Partitioning Horizontal Partitioning Horizontal and Vertical Partitioning Data Replication Vertical Partitioning Horizontal Partitioning Horizontal and Vertical Partitioning Data Replication ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases With failure transparency, all of the actions of a transaction are committed or none of them are committed. False True False True ANSWER DOWNLOAD EXAMIANS APP
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