RelationalDBDesignRelationalDBDesign




Physical Design   «Prev  Next»
Lesson 10Vertical Partitioning
ObjectiveDescribe the characteristics of Vertical Partitioning

Database Vertical Partitioning

Horizontal partitioning redistributes the records in a table into two or more tables in order to reduce the size of the tables used in the most common searches and joins. It is also possible to partition a table into two or more tables that contain every row but not all of the columns in the original table. This process, called vertical partitioning, lets you store the most commonly used columns from a table in a smaller number of blocks on the computer's hard drive.
Consider the records in the following table.

CD Table will be partitioned in 2 tables.
CD Table will be partitioned in 2 tables.



If you discovered that Stories on CD users needed to know the values for a CD's Title and DistID much more often than the values for the CD's Price and AgeGroup, you could divide the table into two tables linked by the original table's primary key field.

CD Table 1: Title and DistID; CD Table 2: Price and AgeGroup
CD Table 1: Title and DistID; CD Table 2: Price and AgeGroup

The next lesson discusses the trade-offs inherent to vertical partitioning.