1. A method for performing queries on a search engine, based on input from a user, the method comprising: retrieving database entries from one or more databases; flattening a plurality of the database entries; indexing the plurality of flattened database entries to form a search engine index; prompting the user to enter an input; continuously monitoring the user input; each time an input is entered by the user, processing the user input by: computing a set of non-null partial queries in response to the input entered by the user; associating a structured item to each non-null partial query; allowing the user to select one of the structured items; if the user selects one of the structured items, replacing the user input by the non-null partial query associated to the selected structured item; when the user validates the input, executing the input as a query; and providing documents to the user corresponding to the executed query.