Providing cached data
When a dashboard or a report uses a data object, each time the dashboard is refreshed or the report is run, the data object connects to the underlying data source and retrieves data from it. This operation is typically resource-intensive. For a more efficient data access alternative, cache the data in a data object store, and provide dashboard and report users with access to the data object store.
How to create a data object store
BIRT creates a data object store (.data file) that contains the materialized data. The file is saved in the same folder in which the data object design file resides.

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