1. A method performed by an apparatus, connected to a source data base and a target data base, said apparatus comprising one or more processors and a memory device having stored computer readable instructions executable by the one or more processors for executing an export process for an automated meta model driven export of entity parts from the source data base, wherein the meta model specifies an abstract model of the source data base and comprises a description of an entity part and/or a reference relationship between entity parts being resolvable from a referencing entity part to a referenced entity part, the method comprising: identifying a set of entity parts being identifiable outside the source data base by a public key, an internal key, or a mixture of a public key and an internal key as first level entity parts; supplementing the identified set of first level entity parts by a set of second level entity parts being referenced by the first level entity parts according to at least one reference relationship described in the meta model; initializing an empty repository as a staging memory for the export process; retrieving the identified set of first level entity parts in sequence from the source data base and adding every retrieved first level entity part to the repository; linking every added first level entity part to its corresponding meta model description; supplementing the repository by: scanning the first level entity parts added to the repository; resolving, for every scanned first level entity part, its reference relationships in a recursive manner to identify related child entity parts; evaluating, for every child entity part, whether it is already added to the repository; adding every child entity part to the repository when it is not yet added; and dumping content of the repository into an export file.
1. A method performed by an apparatus, connected to a source data base and a target data base, said apparatus comprising one or more processors and a memory device having stored computer readable instructions executable by the one or more processors for executing an export process for an automated meta model driven export of entity parts from the source data base, wherein the meta model specifies an abstract model of the source data base and comprises a description of an entity part and/or a reference relationship between entity parts being resolvable from a referencing entity part to a referenced entity part, the method comprising: identifying a set of entity parts being identifiable outside the source data base by a public key, an internal key, or a mixture of a public key and an internal key as first level entity parts; supplementing the identified set of first level entity parts by a set of second level entity parts being referenced by the first level entity parts according to at least one reference relationship described in the meta model; initializing an empty repository as a staging memory for the export process; retrieving the identified set of first level entity parts in sequence from the source data base and adding every retrieved first level entity part to the repository; linking every added first level entity part to its corresponding meta model description; supplementing the repository by: scanning the first level entity parts added to the repository; resolving, for every scanned first level entity part, its reference relationships in a recursive manner to identify related child entity parts; evaluating, for every child entity part, whether it is already added to the repository; adding every child entity part to the repository when it is not yet added; and dumping content of the repository into an export file. 3. The method of claim 1 , wherein the reference relationship in the meta model is selectable as a 1:1 reference being resolvable from a referencing entity part of the source data base to one referenced entity part of the source data base or a 1:n child reference being resolvable from a referencing entity part of the source data base to at least one referenced entity part of the source data base, and wherein the resolving, for every scanned first level entity part, its reference relationships in a recursive manner to identify related child entity parts is executed such that a 1:1 reference is resolved over one level of hierarchy and such that a 1:n child reference is resolved over at least one level of hierarchy.