To access data (returned from single or multiple Web service invocations) through a database table, create a virtual table through a Web service data source. This table function allows you to query a set of returned rows as though it were a table.
The client invokes a Web service and the results are stored in a virtual table in the database. You can pass result sets from function to function, allowing you to set up a sequence of transformation without a table holding intermediate results. To reduce memory usage, you can return the result set rows a few at a time within a function.
By using Web services with the table function, you can manipulate a range of input values (from single or multiple Web services) as a real table. In the following example, the inner
SELECTcreates rows whose columns are used as arguments for invoking the
CALL_WSWeb service call-out. The table expression could be used in other SQL queries, for constructing views, and so on.