1. A computer-implemented method for logically attributing a field of a source physical table to a target physical table both residing in an underlying physical database, the method being implemented by execution of one of more processors and comprising: providing a database abstraction model defining a plurality of logical fields for composing an abstract query, wherein each logical field specifies (i) a name for the logical field and (ii) an access method that maps the logical field to data in the underlying physical database, wherein at least one of the logical fields is defined as a virtual column of the target physical table different than the source physical table where the data for the at least one logical field physically resides, the logical field defined as the virtual column comprising an access method that maps initially to selected data in the source physical table; receiving an abstract query requesting results for at least one of the plurality of logical fields, including the logical field defined as the virtual column; for the received abstract query, creating a first data structure configured to select only the selected data in the source physical table mapped to by the access method of the logical field defined as the virtual column; and for the received abstract query, changing the access method of the logical field defined as the virtual column to map to the first data structure instead of the source physical table; and wherein the database abstraction model and the first data structure are stored on one or more computer readable storage media.