WebSphere
eXtreme Scale is
used to front a traditional database and eliminate read activity that
is normally pushed to the database. A coherent cache can be used with
an application directly or indirectly using an object relational mapper.
The coherent cache can then offload the database or backend from reads.
In a slightly more complex scenario, such as transactional access
to a data set where only some of the data requires traditional persistence
guarantees, filtering can be used to offload even write transactions.
You can configure eXtreme Scale to function as a highly flexible
in-memory database processing space. However,
eXtreme Scale is not an object
relational mapper (ORM). It does not know where the data in
eXtreme Scale came from. An application
or an ORM can place data in an
eXtreme Scale server. It is the
responsibility of the source of the data to make sure that it stays
consistent with the database where data originated. This means
eXtreme Scale cannot invalidate
data that is pulled from a database automatically. The application
or mapper must provide this function and manage the data stored in
eXtreme Scale.
Figure 1. ObjectGrid
as a database buffer
Figure 2. ObjectGrid as a side cache