Hey
I have about 6000 tracks on my PC. I have setup Traktor to read the music folder. When I first opened Traktor it loaded all the tracks. I then set the whole collection to analyze. After a whole day of processing I closed Traktor and then reopened it next day. All of the tracks reappeared but it took ages to appear like it was refreshing/resyncing again.
latest 3.5.3 version.