The retrieval and manipulation of data from large public databases like the U.S. National Health and Nutrition Examination Survey (NHANES) may require sophisticated statistical software and significant expertise that may be unavailable in the university setting. In response, we have developed the Data Retrieval And Manipulation System (DReAMS), an automated information system to handle all processes of data extraction and cleaning and then joining different subsets to produce analysis-ready output. The system is a browser-based data warehouse application in which the input data from flat files or operational systems are aggregated in a structured way so that the desired data can be read, recoded, queried and extracted efficiently. The current pilot implementation of the system provides access to a limited amount of NHANES database. We plan to increase the amount of data available through the system in the near future and to extend the techniques to other large databases from CDU archive with a current holding of about 53 databases.