The CLEAR HINT syntax is used to clear hint settings for current connection.
ClearHint ::=
'CLEAR' ('SHARDING'|'READWRITE_SPLITTING')? 'HINT'
SHARDING/READWRITE_SPLITTING is not specified, the default is clear all hint settings.CLEAR SHARDING HINT;
CLEAR READWRITE_SPLITTING HINT;
CLEAR HINT;
CLEAR, SHARDING, READWRITE_SPLITTING, HINT
