Reducing size of update package data for navigation databases

An apparatus comprising at least one processor and at least one memory including computer program code for one or more programs, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least:

• identify, in or after a second process of compiling data that yields a second navigation database, a navigation data item having a changed position in a list of said second navigation database, wherein said changed position of said navigation data item is different to a previous position of said navigation data item in a list of a first navigation database which is yielded from a first process of compiling data performed before said second process of compiling data,
• generate first update data for updating said first navigation database to an intermediate navigation database in a first updating step, wherein said first update data represents generic update instructions and/or information for changing a data reference pointing to said previous position of said identified navigation data item to a data reference pointing to said changed position of said identified navigation data item;
• determine said intermediate navigation database at least partially based on said first update data and said first navigation database;
• and
• generate second update data for updating said intermediate navigation database to said second navigation database in a second updating step based upon said intermediate navigation database and said second navigation database.

A non-transitory computer readable storage medium including one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to at least perform:

• identifying, in or after a second process of compiling data that yields a second navigation database, a navigation data item having a changed position in a list of said second navigation database, wherein said changed position of said navigation data item is different to a previous position of said navigation data item in a list of a first navigation database which is yielded from a first process of compiling data performed before said second process of compiling data,
• generating first update data for updating said first navigation database to an intermediate navigation database in a first updating step, wherein said first update data represents generic update instructions and/or information for changing a data reference pointing to said previous position of said identified navigation data item to a data reference pointing to said changed position of said identified navigation data item;
• determining said intermediate navigation database at least partially based on said first update data and said first navigation database;
• and
• generating second update data for updating said intermediate navigation database to said second navigation database in a second updating step based upon said intermediate navigation database and said second navigation database.