Why is DEVONthink getting slower and slower?
It’s a good idea to optimize the database from time to time using Tools > Backup & Optmize. If this doesn’t help, you may want to try to rebuild the database from scratch using Tools > Rebuild Database. Both of these options should help restore some of your databases’ zing. Also, DEVONthink is highly dependant on enough RAM, so make sure you have at least 768MB of RAM (the more, the better).