1. A computer implemented method for using secondary mappings to decouple code modifications from database schema updates, said method comprising: under the control of one or more computer systems configured with executable instructions, maintaining one or more mappings between objects residing in an object relational mapping (ORM) system and tables residing in a database; annotating at least one attribute of an object in the ORM system with an annotation to indicate that the attribute is capable of being stored as a secondary mapped attribute; receiving, by the ORM system, at least one read operation or write operation that references an attribute of the object; in response to determining that the attribute referenced by the at least one read operation or write operation corresponds to the at least one annotated attribute of the object, determining whether a first column exists in the database that is directly associated with the attribute of the object that is being referenced by the read operation or the write operation; re-mapping the read operation or the write operation to reference a map in the ORM system corresponding to a second column in the database, the second column designated to store values for attributes that have been annotated with the annotation to indicate secondary mapped attributes if there exists no first column in the database that is directly associated with the attribute being referenced by the read operation or the write operation; determining that a schema of the database has been updated to include the first column after re-mapping the read operation or the write operation to reference the map; mapping subsequent write operations to the first column in the database and removing the values from the map; wherein subsequent read operations continue to be executed against the map in the ORM system until the values are removed from the map by the subsequent write operations; and wherein the subsequent read operations are executed against the first column after the values are removed from the map by the subsequent write operations.