The lvarchar host variables

Your program must manipulate the external data for an lvarchar host variable. If the length of the data that come from an opaque type column does not vary, or if you know the maximum length of the data in an opaque type column, you can use a fixed-size lvarchar host variable. If the size of the data varies from one table row to another, however, use an lvarchar pointer variable and manipulate the data with the ifx_var() functions.