Seamless use of SQL

With the aid of a user-defined primary access method, you can use a SELECT statement to access any of the following data as though the data that is in the HCL Informix® relational table:

Legacy data such as flat-file records
Mixed binary and text data such as a word-processor document
Multiple-vendor data across the enterprise
Mobile device feeds
Internet and intranet application streams
Nonrelational data, such as hierarchically structured Extensible Markup Language (XML) documents

The user can use SQL to access both Informix data and virtual table data. A virtual table requires a user-defined access method to make the data in the table accessible to Informix. In the following figure, a single application processes Informix data and virtual data in an external location and smart-large-object storage.

Figure 1. Using a primary access method

Flowchart shows that a client program can access a table through an SQL engine and a built-in access method. Alternatively, the client program can access a virtual table stored either in an extspace or in an sbspace via an SQL engine and a user-defined access method.