discussion: improve performance of bulk scan

Just read this - http://stackoverflow.com/questions/1711631/how-do-i-improve-the-performance-of-sqlite - about sqlite3 performance. The changes are a proof of concept. On my ubuntu machine the scan performance on startup without this change is ~5 seconds, with this change its not measurable (at least with the simple logging i added).

@ejurgensen is this something you want? I haven't looked close into the scanner code, so if you want, you can take over ...