Database Reference
In-Depth Information
Figure 8.26
Cost after indexing.
Figure 8.27
Drop index.
8.4 Federations
Federations in Windows Azure SQL Database can be used to improve performance and to achieve
better scalability. When multiple applications are accessing a single data source, they may cause a
data I/O bottleneck. One way to ease the bottleneck is to split a database object such as a table and
place each part into diferent partitions. Windows Azure SQL Database Federation is a collection
of the partitions of one or more database objects. With federations, database administrators are
able to systematically build and manage partitions. he processing of a federation is also known as
“sharding.” he following are some terminologies often used in the federation technology:
◾
Federation distribution key
: It contains the values used for specifying partitions. he key
values must be the types of INT, BIGINT, UNIQUEIDENTIFIER, or VARBINARY (up
to 900 bytes).
◾
Federation scheme
: It deines the federation distribution key to determine how the data are
distributed to diferent partitions contained in a federation.
