All tickets are in the #__ats_tickets table. All posts are in the #__ats_posts table. You can write your own SQL query to fetch the aggregate information you want. Please note that aggregate queries are slow – and please don't do a join, this makes things far far far far worse.
Regarding the latest ticket, first query #__ats_tickets table to get the information you want. Then query the #__ats_posts table for all ecords with the same ats_ticket_id and choose the one with the lowers ats_ticket_id to find the first post. The user_id is the Joomla user ID. You can pull up its record through JFactory to display the username.
Nicholas K. Dionysopoulos
Lead Developer and Director
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