Final answer:
The fragmentation approach in a distributed database management system separates the database into smaller parts or fragments that are distributed across different sites, optimising performance, data management, and system reliability. Types of fragmentation include horizontal and vertical fragmentation.
Step-by-step explanation:
The fragmentation approach to setting up a distributed database management system (DDBMS) involves dividing the database into smaller pieces, known as fragments, which are then allocated across various locations or sites within the network. This methodology allows for localized control and management of data, as well as improved efficiency and performance, since queries can be executed on the local fragment of the database rather than on the entire distributed database. Moreover, fragmentation enhances the system's ability to continue operating if a single fragment or site encounters an issue, thereby increasing the overall reliability of the DDBMS.
There are mainly two types of fragmentation in DDBMS: horizontal fragmentation and vertical fragmentation. Horizontal fragmentation divides a database table into subsets of tuples (rows), which are distributed based on certain criteria related to the attributes of the tuples. In contrast, vertical fragmentation divides a table into subsets of attributes (columns), with each subset containing a unique set of attributes and, usually, a common candidate key to ensure proper recombination of the fragments when necessary.
In summary, the fragmentation approach is a conceptual method that involves breaking down a database into more manageable pieces for a distributed environment. This allows for more tailored and efficient operations, maintenance, and potentially improved performance in a distributed database scenario.