Database Reference
In-Depth Information
Aggregation
In its simplest form, the aggregation pattern provides a mechanism to collect data from multiple data
providers into a SQL Azure database. The data providers can be geographically dispersed and not know
about each other, but they must share a common knowledge of the schema so that, when aggregated,
the data is still meaningful.
The aggregation patterns shown in Figure 2-11 use the direct connection pattern. You can use an
aggregation pattern to provide a common repository of information, such as demographic information
or global warming metrics collected from different countries. The key in this pattern is the ability to
define a common schema that can be used by all providers and understood by the consumers. Because
SQL Azure supports XML data types, you can also store certain columns in XML, which provides a
mechanism to store slightly different information per customer.
Figure 2-11.
Aggregation patterns
Mirroring
The mirror pattern, shown in Figure 2-12, is a variation of the offloading pattern where the secondary
consumer can be an external entity. In addition, this pattern implies that a two-way replication topology
exists, so that changes in either database are replicated back to the other database. This pattern allows a
shared nothing
integration in which neither consumer has the authority to connect to the other
consumer directly.
