Embodiments of the invention allow for managing execution of queries with respect to different data sources. The different data sources are logically represented by data abstraction models. One embodiment comprises receiving a first abstract query against physical data in a first data source. The first abstract query has result fields configured to return requested data from the first data source. In response it is detected whether the first data source is available. If the first data source is unavailable, a second abstract query against physical data in a second data source containing a portion of the requested data is created on the basis of the first abstract query. The second abstract query has result fields configured to return the portion of the requested data from the second data source. The second abstract query is executed against the second data source to obtain the portion of the requested data.