Hi, thank you for reaching out. We can not confirm that the `brickname` columns in `ls_dr9.tractor` and `ls_dr8.tractor` are empty. In fact, no single row in these columns is empty; they all an 8-char length string value.
Could you please provide a minimal example of the query where you end up with empty `brickname` columns? You can reply to this post, or if that's easier (e.g. to send a minimal notebook example), you can email to datalab@noirlab.edu, and we'll pick up from there.
Thank you!
Robert