`information_schema.columns_extensions.*`

show items implemented by

any at least two only one database all databases

relation	column	mysql	mariadb	tidb	postgres	cockroachdb	mssql
`columns_extensions`
	`column_name`	`VARCHAR NULL`: 8	unsupported	unsupported	unsupported	unsupported	unsupported
	`engine_attribute`	`JSON NULL`: 8	unsupported	unsupported	unsupported	unsupported	unsupported
	`secondary_engine_attribute`	`JSON NULL`: 8	unsupported	unsupported	unsupported	unsupported	unsupported
	`table_catalog`	`VARCHAR NOT NULL`: 8	unsupported	unsupported	unsupported	unsupported	unsupported
	`table_name`	`VARCHAR NOT NULL`: 8	unsupported	unsupported	unsupported	unsupported	unsupported
	`table_schema`	`VARCHAR NOT NULL`: 8	unsupported	unsupported	unsupported	unsupported	unsupported