1. SQL Azure Federations
Pavlo Revenkov
EPAM Cloud Computing Competency Center
Email: pavlo_revenkov@epam.com
Skype: rp_risingstar

2. Scaling
Horizontal partitioning is a database design principle whereby rows of a
database table are held separately. Each partition forms part of a shard, which
may in turn be located on a separate database server or physical location.
© Wikipedia
Vertical Horizontal
DB
server
DB
server
DB
server
time
Member
#1
Member
#2
…
time
Root
2

3. Does not contain the data anymore.
It is distributed across shards.Root
Horizontal scaling 3

4. Infrastructure 4
Federation
root
Federation
member
…
- contains federation metadata;
- global database data;
- route connections.
- provides physical data separation;
- can have its own schema;
Atomic unit
Federation
member
- the collection of all rows in a
federation member that match
a specific federation key value.

5. Limitations 5
• The federation distribution key must be an
INT, BIGINT, UNIQUEIDENTIFIER, or VARBINARY and specifies a
range value.
• Federation columns cannot be NULL-able.
• Federated members do not support the IDENTITY property.
• Reference tables cannot have foreign key relationships with federated
tables. Federated tables can have foreign key relationships with
reference tables without restrictions.
• Each federation member cannot be larger than 150 GB.
• Cross database joins are not supported. An application must implement
the logic for joining data from multiple federation members or multiple
federations.

6. Demo 6

7. References
Federations in Windows Azure SQL Database:
 http://msdn.microsoft.com/en-us/library/windowsazure/hh597452.aspx
SQL Database Federations Tutorial:
 http://msdn.microsoft.com/en-us/library/windowsazure/hh778416.aspx
Federation Guidelines and Limitations:
 http://msdn.microsoft.com/en-us/library/windowsazure/hh597469.aspx
7

8. Questions? 8