Oracle Corporation
Efficient extraction of large data sets from a database

Abstract:

A method of efficiently extracting large data sets from a database includes receiving a query to be executed on a first view of one or more data sources, where previous result sets resulting from previous queries are stored separately from the one or more data sources. The method also includes receiving a current result set from the one or more data sources that is responsive to the query, where the query is reformatted before it is executed such that the result set does not overlap with the previous result sets. The method additionally includes generating a second view that combines the current result set and the one or more previous result sets, where the second view resolves changes in a schema of the one or data sources between when the previous result sets were received and when the current result set is received.