`information_schema.routine_routine_usage.*`

show items implemented by

any at least two only one database all databases

relation	column	mysql	mariadb	tidb	postgres	cockroachdb	mssql
`routine_routine_usage`
	`routine_catalog`	unsupported	unsupported	unsupported	`SQL_IDENTIFIER NULL`: 14-15	unsupported	unsupported
	`routine_name`	unsupported	unsupported	unsupported	`SQL_IDENTIFIER NULL`: 14-15	unsupported	unsupported
	`routine_schema`	unsupported	unsupported	unsupported	`SQL_IDENTIFIER NULL`: 14-15	unsupported	unsupported
	`specific_catalog`	unsupported	unsupported	unsupported	`SQL_IDENTIFIER NULL`: 14-15	unsupported	unsupported
	`specific_name`	unsupported	unsupported	unsupported	`SQL_IDENTIFIER NULL`: 14-15	unsupported	unsupported
	`specific_schema`	unsupported	unsupported	unsupported	`SQL_IDENTIFIER NULL`: 14-15	unsupported	unsupported