Q.1

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

  • True
  • False
Q.2

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.
Q.3

Replication should be used when which of the following exist?

  • 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.
  • The application's data can be somewhat out-of-date.
  • All of the above.
Q.4

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

  • Data Replication
  • Horizontal Partitioning
  • Vertical Partitioning
  • Horizontal and Vertical Partitioning
Q.5

A transaction manager is which of the following?

  • Maintains a log of transactions
  • Maintains before and after database images
  • Maintains appropriate concurrency control
  • All of the above.
Q.6

Location transparency allows for which of the following?

  • Users to treat the data as if it is at one location
  • Programmers to treat the data as if it is at one location
  • Managers to treat the data as if it is at one location
  • All of the above.
Q.7

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.8

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

  • True
  • False
Q.9

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

  • True
  • False
Q.10

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.11

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.12

A distributed database can use which of the following strategies?

  • Totally centralized at one location and accessed by many sites
  • Partially or totally replicated across sites
  • Partitioned into segments at different sites
  • All of the above
Q.13

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.14

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.15

The problem of concurrency control is more complex in a distributed database.

  • True
  • False
0 h : 0 m : 1 s