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.