I've read the documentation but am unclear on what memory is used when
temp_buffers are exceeded by temp tables that are created. Does that also
go towards temp_file_limit?
When are temp files (temp_file_limit) cleared out? If there is a big ugly
query that uses 8GB of a 10GB limit, and then another query in the same
connection wants to use 3GBs of temp files total, will it fail? Or will
those earlier temp files have been cleared or otherwise be ignored?