Exam 12: Distributed Databases

With ________,users can act as if all the data were located at a single node.

An environment in which data are distributed across all nodes,and there is a global schema,is called a(n)________ environment.

With an asynchronous distributed database,all data across the network is continuously kept up-to-date.

Which of the following are business conditions that encourage the use of distributed databases?

Combining data across vertical partitions is generally more difficult than combining across horizontal partitions.

Applications that can tolerate out-of-date data are not the best candidates for data replication.

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

The overriding principle in distributed database design is that data should be stored at one central site.

A local transaction is one that requires reference only to data that are stored at the site where the transaction originates.

What are the functions of a distributed DBMS?

What are the three steps that a distributed DBMS uses to develop a query plan?

An optimization strategy that permits each part of a transaction to be committed in sequence is called ________ optimization.

A synchronized replication strategy has a(n)________ reliability.

Two-phase commit is an algorithm for coordinating deletions in a distributed database management system.

The sequence of instructions required to process a transaction is called the:

The step in which a distributed database decides the order in which to execute the distributed query is called:

In a heterogeneous environment,not all users use the same DBMS.

Applications such as decision support or data warehousing often do not require current data and are supported by periodic snapshots.

What are some of the advantages and disadvantages of a distributed database?

What is data replication?