You can use XnView to transform Windows picture thumbnail database (*.db) to PDF. Open XnView → Double click on .db file → Click on File menu → Save as... → file format: Portable Document Format → Click on Save button.
Found 2 different conversion types using the same filename extensions.
Conversion db to pdf type 1:
Convert from Corel Paradox database to Adobe Portable document format.
Microsoft Windows software - convert db to pdf on Windows
A spreadsheet software application from Corel
File type (from-> to)
Convert from db file format
Corel Paradox database
|Yes, Corel Quattro Pro supports db file conversion as a source file type.||Yes||Yes||db editor||Yes||No||No||No|
Adobe Portable document format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned db to pdf. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Conversion db to pdf type 2:
Convert from Database file to Adobe Portable document format.
Multiplatform software - convert db to pdf on any platform
SQLite database manager