$LobReserve
Function
The $LOBRESERVE function returns the number of bytes specified in the RESERVE n BYTES clause for a STORE or ADD statement of a BINARY-LARGE-OBJECT (BLOB) or a CHARACTER-LARGE-OBJECT (CLOB). A RESERVE n BYTES clause is used when the data being stored will be changed later to a value of n bytes.
The $LOBRESERVE function takes one argument that can be a field name or a field name variable (%%variable).
$LOBRESERVE(Large-Object-fieldname | %%variable)