What database table and fields hold the ticket 'assigned' value? Trying to query time from ticket creation to assignment.

Use the official database ERDs at https://docs.osticket.com/en/latest/DeveloperDocumentation/DatabaseERDs.html. The assignment event is tracked via the thread system: ost_ticket → ost_thread (where object_id = ticket's primary key/ticket_id and object_type = 'T') → ost_thread_event (linked by thread_id) → ost_event (linked by event_id). The 'assigned' designation appears as an event entry in ost_thread_event.