Crash course on database rights: Duration of database protection
The term of protection for a sui generis database right is fifteen years from the first of January of the year following the date of completion (article 10(1)). If the database is offered to the public in any way before this fifteen-year period expires, then instead the period runs out on the first of January of the year following the date that the database was first made available to the public (article 10(2)).
The term is extended automatically if a substantial change is made to the database during the term of protection. The requirement for determining whether a change is "substantial" is the same as for determining whether it qualifies for protection in the first place.
If a database is protected by copyright, the duration of its protection of course lasts until the copyright runs out. Typically this term is 70 years after the death of the maker.