As you probably know, Opera 15 – as do many browsers – uses SQLite databases to store various data. Perhaps one of the most interesting SQLite database for Opera is the
Web Data db, which stores autofill data as well as the search engine definitions (in the
`keywords` table). The
Thumbnails database can be modified if you like to have your own speeddial icons instead of the automatically generated screenshots.
Those screenshots consist of binary data and many free SQLite GUI editors cannot handle that. One of those editors – regarding the Windows OS – is the SQLiteBrowser v2 you probably stumbled upon already searching the interwebs for such applications. It cannot handle BLOBs and the interface is not very comfortable to work with (no drag and drop opening, eg).
[Edited December 2014:] The database editor fork is now called ”Database Browser for SQLite“. Binaries are available on that new dedicated web site, while the sources have been moved to another Github repository. It’s even more recommendable now!
I recommend it. 🙂