Seamless Use of SQL

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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 resided in an IBM 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 end user can use SQL to access both IBM Informix data and virtual table data. A virtual table requires a user-defined access method to make the data in the table accessible to Dynamic Server. In Figure 1, a single application processes IBM Informix data as well as 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 an Informix table via 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.