1. A method for processing and transferring data from a file system to a database system, the method comprising the steps of: receiving a query containing a request for accessing data from a file system, wherein the request for accessing data identifies a plurality of attributes, each attribute being associated with an object identifier; determining, based on the query, whether at least one partition of at least one attribute of the data has been previously loaded into the database system; incrementally loading, based on a determination that the at least one partition of at least one attribute of the data has not been previously loaded into the database system, the at least one partition of the at least one attribute of the data into the database system while continuing to process the query without loading all attributes in the plurality of attributes identified by the request at the time of receiving the query, and without loading the at least one partition of at least one attribute of the data into the database system upon determination that the at least one partition has been previously loaded into the database system, the determination is being made based on a catalog containing a mapping of a portion of the plurality of attributes that has been previously loaded into the database system, the at least one loaded partition of the at least one attribute is being stored together with the object identifier associated with the at least one attribute; and joining the at least one loaded partition and at least another loaded partition of at least another attribute using the object identifier associated with the at least one attribute and another object identifier associated with the at least another attribute, to generate a dataset responsive to the received query; wherein the incremental loading is performed during a map phase of a MapReduce processing task.