I added a custom field for authenticated users to add a bio on their profile page (and if there's an existing field I should use for this, please let me know). Not knowing how long I should make this field, and temporarily forgetting that mysql probably uses fixed-width for this, I set the field length to 32767.
It took a long time to create the field, but the page wait dialog finally completed and the field shows up in the Custom Fields list. But having seen the long wait, I decided to re-do the field at 4095 or 8191, and tried to delete the Bio field. THAT progress window has been a spinning blue circle for nearly an hour, and Bio is still showing up in the Custom Fields list in a different tab.
EDIT: perhaps worth noting that the page where I created the field also had a spinning wait cursor nearly 90 minutes after I did so, but I could see the Bio field as expected in the Custom Field list, so that process seems to have completed without letting the page know.
Did I break something, or will this get to my desired state after I wait long enough? This is running on a Linode at $20 a month, so the CPU/RAM is not particularly powerful.