V$TYPE_SIZE

V$TYPE_SIZE displays the sizes of various database components for use in estimating data block capacity.

Column	Datatype	Description
`COMPONENT`	`VARCHAR2(8)`	Component name, such as segment or buffer header
`TYPE`	`VARCHAR2(8)`	Component type
`DESCRIPTION`	`VARCHAR2(32)`	Description of the component
`TYPE_SIZE`	`NUMBER`	Size of the component
`CON_ID`	`NUMBER`	The ID of the container to which the data pertains. Possible values include: `0`: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. `1`: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data