1. A method, comprising: presenting a user interface to receive user input specifying a database for a business process management (BPM) system operable with a plurality of database types, the plurality of database types comprising three or more separate database types, wherein the user input specifying the database does not comprise an indication of a database type of the database for the BPM system or differences between the database and other databases of the plurality types; installing the BPM system, wherein the installing comprises creating a schema for the database using a database definition comprising uniform elements and parameters supported by all of the plurality of database types, the database definition specifying tables, table columns and data types, wherein the data types are recognizable by all of the plurality of database types, each of the plurality of database types having one or more features that are inapplicable to other ones of the plurality of database types; executing, by a processing device, a definition of a business process using the BPM system, the definition of the business process being expressed in a business process language; and when executing the definition of business process, accessing, by the BPM system, the database, wherein accessing the database comprises receiving a request pertaining to a data object, mapping, using a mapping document, the data object to a database element in the schema for the database, wherein the mapping document is separate from the database definition and the mapping document specifies database elements and element properties that are uniform for all databases supported by the BPM system, the properties being recognizable by any of the plurality of database types, and performing a database operation for the database element according to the request.