App Studio > Creating Metadata > Accessing Data

Accessing Data

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When your App Studio application accesses data, App Studio needs to know how to interpret the data that it finds. A Master File, which is the primary component of metadata, is a map of the segments in the data source and all of the fields in each segment. The Master File also identifies the name of the data source and the type of data source it is.

For some types of data sources, the Master File is supplemented by an Access File. An Access File includes additional information that completes the description of the data source. For example, it includes the full data source name and location. You require one Master File and, for some data sources, one Access File to describe a data source. These metadata files (Master File and Access File) are referred to as a synonym.

Synonyms are stored separately, apart from the associated data source. Your App Studio application uses a synonym to interpret a data source as follows:

  1. It identifies the data sources available and their respective fields.
  2. It examines the security rules, if Information Builders data source security (DBA) has been specified for the data source, and ensures that user access is allowed based on any DBA security specified.
  3. It identifies the Access File for the data source, if that data source requires an Access File.

The data source content is interpreted based on the information in the Master File and, if applicable, the Access File.

Working With Data Adapters

With the appropriate WebFOCUS Data Adapters, you can access data from many different sources, including the following:

  • Relational data sources, such as Db2 and Oracle.
  • Hierarchical data sources, such as IMS and FOCUS.
  • Indexed data sources, such as ISAM and VSAM.
  • Network data sources, such as CA-IDMS.
  • Sequential data sources, both fixed-format and delimited format.
  • Multi-dimensional data sources, such as SAP BW and Essbase.
  • XML data sources.

Every adapter is specifically designed for the data source that it accesses, and, as a result, is able to translate between SQL or WebFOCUS and the data management language (DML) of the data source. The adapter manages the communication between the data interface and the data source and returns either answer sets or messages to the requestor. Adapters provide solutions to product variations, including product differences in syntax, functionality, schema, data types, catalogs, data representations, message processing, and answer set retrieval. It is the adapter that manages the synonym creation process.

The parameters required to configure supported adapters and to create synonyms for the corresponding data sources are described in detail in the Adapter Administration manual.

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