Clustering And Partitioning

Multitable Clustering

Multitable clustering is great for storing tables that are often joined with each other. In a cluster, tables records are stored interleaved with each other.

dept_name	building	budget
CSE	Taylor	100000
PHY	Watson	70000

ID	name	dept_name	salary
100	Hector	CSE	65000
101	Robin	PHY	57000
102	Seth	CSE	58000
103	Genny	CSE	70000

These two tables will be merged into the cluster

__	__	__	__
CSE	Taylor	100000
100	Hector	CSE	65000
102	Seth	CSE	58000
103	Genny	CSE	70000
PHY	Watson	70000
101	Robin	PHY	57000

This won't work very well when you're querying for only one table, but makes joins faster. This is stored in variable-length records

Partitioning

In partitioning, a single table \(X\) is broken into multiple tables \(\{X_i\}\) . Each table \(X_i\) can be stored separately. * This reduces cost of some operations like free space management. * It allows different partitions to be stored on different devices, like storing more important partitions on an SSD and less important ones on a magnetic disk.