An increasingly popular option for data distribution as well as for fault tolerance of any database is to store a separate copy of the database at each of two or more sites.
An increasingly popular option for data distribution as well as for fault tolerance of any database is to store a separate copy of the database at each of two or more sites.
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.
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.
Replication should be used when which of the following exist?
Replication should be used when which of the following exist?
An autonomous homogenous environment is which of the following?
An autonomous homogenous environment is which of the following?
A distributed database can use which of the following strategies?
A distributed database can use which of the following strategies?
A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations.
A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations.
Data replication is favored where most process requests are read-only and where the data are relatively static.
Data replication is favored where most process requests are read-only and where the data are relatively static.
Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment.
Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment.
Some of the columns of a relation are at different sites is which of the following?
Some of the columns of a relation are at different sites is which of the following?
Which of the following is true concerning a global transaction?
Which of the following is true concerning a global transaction?
A transaction manager is which of the following?
A transaction manager is which of the following?
A distributed database is which of the following?
A distributed database is which of the following?
Location transparency allows for which of the following?
Location transparency allows for which of the following?
Which of the following is a disadvantage of replication?
Which of the following is a disadvantage of replication?
Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases.
Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases.
The semijoin approach saves network traffic.
The semijoin approach saves network traffic.
The problem of concurrency control is more complex in a distributed database.
The problem of concurrency control is more complex in a distributed database.
The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex.
The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex.
Which of the following is not one of the stages in the evolution of distributed DBMS?
Which of the following is not one of the stages in the evolution of distributed DBMS?
The purpose of timestamping is to avoid the use of locks.
The purpose of timestamping is to avoid the use of locks.
With asynchronous technology, if any copy of a data item is updated anywhere on the network, the same update is immediately applied to all other copies or it is aborted.
With asynchronous technology, if any copy of a data item is updated anywhere on the network, the same update is immediately applied to all other copies or it is aborted.
A heterogeneous distributed database is which of the following?
A heterogeneous distributed database is which of the following?
A distributed database has which of the following advantages over a centralized database?
A distributed database has which of the following advantages over a centralized database?
In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned.
In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned.
Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system.
Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system.
With failure transparency, all of the actions of a transaction are committed or none of them are committed.
With failure transparency, all of the actions of a transaction are committed or none of them are committed.
A homogenous distributed database is which of the following?
A homogenous distributed database is which of the following?
Synchronization for pull replication is less disruptive and occurs only when needed by each site, not when a central master site thinks it is best to update.
Synchronization for pull replication is less disruptive and occurs only when needed by each site, not when a central master site thinks it is best to update.
A semijoin is which of the following?
A semijoin is which of the following?
Storing a separate copy of the database at multiple locations is which of the following?
Storing a separate copy of the database at multiple locations is which of the following?
