7. A system comprising: program code comprising: an object management system to call a constructor to register an interface to a description of a persistent class; and a database management system kernel to access the registered interface to determine an internal structure of the persistent class, to process an instance of the persistent class based on the determined internal structure, wherein the instance of the persistent class is a persistent database object, to determine, based on the determined internal structure, members of the persistent database object that are filled with default values, to store the persistent database object in a database, to reduce storage demands on the database by removing the default values from the persistent database object before the storing of the persistent database object in the database, to read the persistent database object from the database after the storing of the persistent database object in the database, to populate the determined members of the persistent database object with the default values after the reading of the persistent database object from the database, to define an index associated with one or more members of the instance based on the determined internal structure and to verify referential integrity of the instance; and at least one processor to execute the program code.
7. A system comprising: program code comprising: an object management system to call a constructor to register an interface to a description of a persistent class; and a database management system kernel to access the registered interface to determine an internal structure of the persistent class, to process an instance of the persistent class based on the determined internal structure, wherein the instance of the persistent class is a persistent database object, to determine, based on the determined internal structure, members of the persistent database object that are filled with default values, to store the persistent database object in a database, to reduce storage demands on the database by removing the default values from the persistent database object before the storing of the persistent database object in the database, to read the persistent database object from the database after the storing of the persistent database object in the database, to populate the determined members of the persistent database object with the default values after the reading of the persistent database object from the database, to define an index associated with one or more members of the instance based on the determined internal structure and to verify referential integrity of the instance; and at least one processor to execute the program code. 9. The system according to claim 7 , the database management system kernel further to define a key associated with one or more members of the instance based on the determined internal structure.