Distributed Databases

Question 1

What is a distributed dataase?

Answer 1

A collection of interconnected local databases that are physically seperate.

Question 2

What are the 2 desirable properties of a Distributed Database?

Answer 2

Location Transparency : Ensures that the database is interpreted as one system by users.
Local Authority : Each local database can be independently managed and run, regardless of the states of the other local databases.

Question 3

What are the 2 types of Distributed Databases? (Regarding DBMS)

Answer 3

Homogenous : All DBMS’s are the same across local databases. No translator needed.
Heterogenous : DBMS’s are different across the system. Thus each local database needs a translator for incoming transmissions.

Question 4

What is data fragmentation?

Answer 4

The segmentation of the database into subsets which can then be stored on separate local databases.

Question 5

Define the 3 types of data allocation and replication…

Answer 5

Full replication : Each local site holds a copy of the entire database.
Data-redundant allocation : Each local database holds exactly one data fragment.
Partial Replication : Data that is accessed across multiple sites can be replicated on those sites.