Distributed Databases(Ict-Basic)Q1

A semijoin is which of the following?

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Only the joining attributes are sent from one site to another and then only the required rows are returned.
All of the attributes are sent from one site to another and then only the required rows are returned.
Only the joining attributes are sent from one site to another and then all of the rows are returned.
All of the attributes are sent from one site to another and then only the required rows are returned.

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

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Replication should be used when which of the following exist?

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The application's data can be somewhat out-of-date.

A transaction manager is which of the following?

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A distributed database has which of the following advantages over a centralized database?

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A heterogeneous distributed database is which of the following?

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

A distributed database is which of the following?

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

A distributed database can use which of the following strategies?

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An autonomous homogenous environment is which of the following?

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A different DBMS is at each node and a central DBMS coordinates database access.
A different DBMS is at each node and each DBMS works independently.
The same DBMS is at each node and each DBMS works independently.
The same DBMS is at each node and a central DBMS coordinates database access.

A homogenous distributed database is which of the following?

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A different 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.
The same 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.

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

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Which of the following is true concerning a global transaction?

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

Location transparency allows for which of the following?

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Which of the following is a disadvantage of replication?

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Distributed Databases(Ict-Basic)Q1 : Question 1 of 14