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Lesson 11Downside to vertical partitioning
Objective Describe the trade-offs inherent to Vertical Partitioning

Disadvantages of Vertical Partitioning

Like horizontal partitioning, vertical partitioning offers performance advantages and disadvantages, depending on the data a particular operation requires. The performance advantages of vertical partitioning come into play if a join uses only the fields in one of the vertically partitioned tables.
In the example presented in the preceding operations which required only a CD's CDNo and Price would run much more quickly after vertical partitioning because the computer would spend less time reading data from disk and manipulating it in memory.

Database Design and Implementation
Partitioned tables:
Table 1 consists of primary key CDNo, CDTitle, DistID
Table 2 consists of primary key CDNo, Price, AgeGroup

If, however, the operation required the entire original table (or at least columns not stored in the same partition), the RDBMS would need to join the partitions into a single table, a relatively slow operation.
As with horizontal partitioning, deciding whether or not to vertically partition a table depends entirely on how your users interact with the contents of your database.
The next lesson explains how to use SQL to implement the physical model of a database.

Vertically Partitioning Table - Quiz

Before you move on to the next lesson, click the Quiz link below to reinforce your understanding of partitioning.
Vertically Partitioning Table - Quiz