Patent attributes
A computer system transforms data. The system displays a user interface including a data flow pane. A user builds a flow diagram in the data flow pane. Each node in the flow diagram specifies an operation: to retrieve data, to transform data, or to create an output dataset. The flow diagram includes a subtree having a data source node and transformation operation nodes. When the user initiates execution and the nodes in the subtree are configured to execute imperatively, the system performs the operations in the subtree sequentially as specified, retrieving data from the data source, transforming the data, and forming an intermediate dataset. When the user initiates execution and the nodes in the subtree are configured to execute declaratively, the system constructs a database query that is logically equivalent to the operations specified in the subtree and transmits the query to the data source to retrieve the intermediate dataset.