alter_rename_index_stmt ::=
	'ALTER' 'INDEX' table_name '@' index_name 'RENAME' 'TO' index_name
	| 'ALTER' 'INDEX' table_name 'RENAME' 'TO' index_name
	| 'ALTER' 'INDEX' 'IF' 'EXISTS' table_name '@' index_name 'RENAME' 'TO' index_name
	| 'ALTER' 'INDEX' 'IF' 'EXISTS' table_name 'RENAME' 'TO' index_name
