User guide

Data Integration with Sybase Avaki Studio 3
What is a view model?
Thus, a view model consists of
• Zero or more input sources
• Zero or more operators to manipulate the data
• Exactly one Result element
Avaki Studio vs. writing your own data service plug-in
Because of its graphical nature and rich user interface, Studio is the preferred way to
create many data services. However, data services created in Studio are fundamentally
relational in nature; while they can take in nonrelational data, the first step in doing so
in Studio is to specify a transformation on that data that yields a relational result. If
you want your data service to work or produce results outside the relational paradigm,
you’ll need either to use one of the built-in plug-ins provided by Sybase or to build a
data service plug-in of your own. (You might use the built-in no-operation plug-in to
provision a web service’s data as XML, or the XSLT plug-in to use XSLT to process one
or more XML inputs.) For another format—a data service that does image processing,
perhaps—you’d write your own plug-in.
For information on Avaki’s built-in data service plug-ins and on writing your own
plug-ins in Java, JavaScript, or XSLT, see the Sybase Avaki EII Provisioning and
Advanced Data Integration Guide.
Schemas
Each result set in a view model, from the inputs to the result, is defined by a schema
consisting of an ordered set of typed columns. The output schema of the view model is
the schema of the operator that is directly connected to the Result element.
Studio lets you display the schema information for any element in a view model. By
manipulating the properties of some operators, you can also alter the output schema.
Schemas are shown in the Table Schema tab of the bottom pane of the Avaki perspec-
tive.
Studio looks for schemas (.xsd files) for input sources in the Avaki domain’s /Meta-
data directory. Note, however, that newly created database operations and data ser-
vices have no metadata. To create metadata, you must either execute the database
operation or data service, or use Studio’s “generate schema” feature. For information
on generating schemas, see “The data catalog view” on page 18.