Application programs can provide key/value connection attributes
to be passed to the server at connect time, using the
mysql_options4() C API
functions. The Performance Schema provides tables that expose
this information through SQL statements:
Both tables have the same columns. The difference between them
displays connection attributes for all sessions, whereas
displays connections only for your own account.
The connection identifier for the session.
The attribute name.
The attribute value.
The order in which the attribute was added to the set of connection attributes.