MCQ Exam Test

Q1

In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned.

A True
B False

Q2

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.

A True
B False

Q3

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 True
B False

Q4

The semijoin approach saves network traffic.

A True
B False

Q5

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 True
B False

Q6

Which of the following is a disadvantage of replication?

A Reduced network traffic
B If the database fails at one site, a copy can be located at another site.
C Each site must have the same storage capacity.
D Each transaction may proceed without coordination across the network.

Q7

With failure transparency, all of the actions of a transaction are committed or none of them are committed.

A True
B False

Q8

The purpose of timestamping is to avoid the use of locks.

A True
B False

Q9

A distributed database can use which of the following strategies?

A Totally centralized at one location and accessed by many sites
B Partially or totally replicated across sites
C Partitioned into segments at different sites
D All of the above

Q10

Data replication is favored where most process requests are read-only and where the data are relatively static.

A True
B False

Q11

Replication should be used when which of the following exist?

A When transmission speeds and capacity in a network prohibit frequent refreshing of large tables.
B When using many nodes with different operating systems and DBMSs and database designs.
C The application's data can be somewhat out-of-date.
D All of the above.

Q12

A homogenous distributed database is which of the following?

A The same DBMS is used at each location and data are not distributed across all nodes.
B The same DBMS is used at each location and data are distributed across all nodes.
C A different DBMS is used at each location and data are not distributed across all nodes.
D A different DBMS is used at each location and data are distributed across all nodes.

Q13

Some of the columns of a relation are at different sites is which of the following?

A Data Replication
B Horizontal Partitioning
C Vertical Partitioning
D Horizontal and Vertical Partitioning

Q14

A heterogeneous distributed database is which of the following?

A The same DBMS is used at each location and data are not distributed across all nodes.
B The same DBMS is used at each location and data are distributed across all nodes.
C A different DBMS is used at each location and data are not distributed across all nodes.
D A different DBMS is used at each location and data are distributed across all nodes.

Q15

Which of the following is true concerning a global transaction?

A The required data are at one local site and the distributed DBMS routes requests as necessary.
B The required data are located in at least one nonlocal site and the distributed DBMS routes requests as necessary.
C The required data are at one local site and the distributed DBMS passes the request to only the local DBMS.
D The required data are located in at least one nonlocal site and the distributed DBMS passes the request to only the local DBMS.

Q16

Storing a separate copy of the database at multiple locations is which of the following?

A Data Replication
B Horizontal Partitioning
C Vertical Partitioning
D Horizontal and Vertical Partitioning

Q17

Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system.

A True
B False

Q18

A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations.

A True
B False

Q19

A semijoin is which of the following?

A Only the joining attributes are sent from one site to another and then all of the rows are returned.
B All of the attributes are sent from one site to another and then only the required rows are returned.
C Only the joining attributes are sent from one site to another and then only the required rows are returned.
D None of the above

Q20

Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment.

A True
B False

Q21

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.

A True
B False

Q22

The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex.

A True
B False

Q23

A distributed database is which of the following?

A A single logical database that is spread to multiple locations and is interconnected by a network
B A loose collection of file that is spread to multiple locations and is interconnected by a network
C A single logical database that is limited to one location.
D A loose collection of file that is limited to one location.

Q24

Which of the following is not one of the stages in the evolution of distributed DBMS?

A Unit of work
B Remote unit of work
C Distributed unit of Work
D Distributed request

Q25

Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases.

A True
B False

dbms - Part 24

In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned.

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.

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.

The semijoin approach saves network traffic.

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.

Which of the following is a disadvantage of replication?

With failure transparency, all of the actions of a transaction are committed or none of them are committed.

The purpose of timestamping is to avoid the use of locks.

A distributed database can use which of the following strategies?

Data replication is favored where most process requests are read-only and where the data are relatively static.

Replication should be used when which of the following exist?

A homogenous distributed database is which of the following?

Some of the columns of a relation are at different sites is which of the following?

A heterogeneous distributed database is which of the following?

Which of the following is true concerning a global transaction?

Storing a separate copy of the database at multiple locations is which of the following?

Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system.

A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations.

A semijoin is which of the following?

Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment.

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.

The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex.

A distributed database is which of the following?

Which of the following is not one of the stages in the evolution of distributed DBMS?

Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases.

Report a problem