Horizontal vs Vertical Fragmentation in Distributed Database Management Systems (DDBMS)

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In the context in DDBMS, what is the difference between Vertical Fragmentation and Horizontal Fragmentation?

Is it such that the relation's extension is fragmented for vertical fragmentation and intension fragmentation is horizontal fragmentation?

 

Suppose you have a relation say Student.

You divide relation Student in two sets say set1 and set2 such that half of the attributes of Student is in set1 and half of them is in set2. This is called Vertical Fragmentation as a relation is fragmented along columns(similar to tearing a page vertically).Original relation is obtained by natural join of all the sets. For natural join we require at least one attribute which is common to all the sets(generally its the Primary Key).

But if our relation divided so that a subset of rows(see here all attributes are present in rows) is present with site1(say), another subset is present with site2, and so on,this is called Horizontal Fragmentation, and Original Relation is obtained by taking union of all the sets.Its like tearing a page horizontally.

As is clear, this is in the context of Distributed DBMS.