Question

"15. describe the three data fragmentation strategies. give some examples of each."

Answer 1

1. Horizontal fragmentation – a table is separated into groups of rows rationally and each fragment (group/sunset) comprises unique rows and it is kept at different node. All rows have the same attributes and the SELECT statement yields the contents of the fragments.
2. Vertical fragmentation – the table is distributed into rational groups of attributes (columns). Each fragment covers a unique columns and is stored at a dissimilar position. The content in the fragment is attained by using the “PROJECT” statement.
3. Mixed fragmentation –This approach is the mix of horizontal and vertical strategies. In other words, each row fragment may be a blend of groups of attributes.