Q.1
A heterogeneous distributed database is which of the following?
  • The same DBMS is used at each location and data are not distributed across all nodes.
  • The same DBMS is used at each location and data are distributed across all nodes.
  • A different DBMS is used at each location and data are not distributed across all nodes.
  • A different DBMS is used at each location and data are distributed across all nodes.
Q.2
What are the characteristics of Unix semantics ?
  • Easy to implement in a single processor system
  • Data cached on a per process basis using write through case control
  • Write-back enhances access performance
  • All of the mentioned
Q.3
Logical extension of computation migration is
  • data migration
  • system migration
  • thread migration
  • process migration
Q.4
Datanodes and namenode are two elementsof which file system?
  • afs
  • hdfs
  • nfs
  • none of the above
Q.5
The problem of concurrency control is more complex in a distributed database.
  • True
  • False
Q.6
In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned.
  • True
  • False
Q.7
The semijoin approach saves network traffic.
  • True
  • False
Q.8
The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex.
  • True
  • False
Q.9
Data replication is favored where most process requests are read-only and where the data are relatively static.
  • True
  • False
Q.10
The purpose of timestamping is to avoid the use of locks.
  • True
  • False
Q.11
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.
  • True
  • False
Q.12
A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations.
  • True
  • False
Q.13
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.
  • True
  • False
Q.14
Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases.
  • True
  • False
Q.15
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.
  • True
  • False
Q.16
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.
  • True
  • False
Q.17
Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment.
  • True
  • False
Q.18
With failure transparency, all of the actions of a transaction are committed or none of them are committed.
  • True
  • False
Q.19
Which of the following is not one of the stages in the evolution of distributed DBMS?
  • Unit of work
  • Remote unit of work
  • Distributed unit of Work
  • Distributed request
Q.20
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.
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