Distributed Databases A transaction manager is which of the following? 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 All of these ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned. 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. False True False True ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Replication should be used when which of the following exist? All of these When using many nodes with different operating systems and DBMSs and database designs. When transmission speeds and capacity in a network prohibit frequent refreshing of large tables. The application's data can be somewhat out-of-date. All of these When using many nodes with different operating systems and DBMSs and database designs. When transmission speeds and capacity in a network prohibit frequent refreshing of large tables. The application's data can be somewhat out-of-date. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Which of the following is a disadvantage of replication? Reduced network traffic If the database fails at one site, a copy can be located at another site. Each site must have the same storage capacity. Each transaction may proceed without coordination across the network. Reduced network traffic If the database fails at one site, a copy can be located at another site. Each site must have the same storage capacity. Each transaction may proceed without coordination across the network. ANSWER DOWNLOAD EXAMIANS APP
Distributed Databases Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment. True False True False ANSWER DOWNLOAD EXAMIANS APP
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