Application programs can provide key/value connection
attributes to be passed to the server at connect time, using
mysql_options4() C API
functions. For descriptions of common attributes, see
Section 22.11.8, “Performance Schema Connection Attribute Tables”.
contains connection attributes for all sessions. To see
connection attributes only for sessions open for your own
account, look in the
contains these columns:
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.