DigiKam is an advanced digital photo management application which enables user to view, manage, edit, organize, tag and share photographs under Linux systems. DigiKam has a feature to search items by similarity. This require to compute image fingerprints stored in main database. These data can take space on disk especially with huge collection and bloat the main database a lots and increase complexity to backup main database which include all main information for each item registered, as tags, label, comments, etc. The goal of this proposal is to store the similarity fingerprints must be stored in a dedicated database (as for Face management database, which store face histograms in a dedicated database).