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. 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. All of the attributes are sent from one site to another and then only the required rows are returned. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Which of the following is a disadvantage of replication? 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. If the database fails at one site, a copy can be located at another site. 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 Location transparency allows for which of the following? Programmers to treat the data as if it is at one location Managers to treat the data as if it is at one location Users to treat the data as if it is at one location All of these Programmers to treat the data as if it is at one location Managers to treat the data as if it is at one location Users to treat the data as if it is at one location All of these 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 The application's data can be somewhat out-of-date. 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. All of these The application's data can be somewhat out-of-date. 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. All of these ANSWER DOWNLOAD EXAMIANS APP