There is a typo in the manual, I think it should be cv$ and not cv$ (page 146)
variable . This variable receives the total number of columns in the cursor. Note that this is not necessarily the same as the size of the array.
SQL.NEXT done, cursor, cv$, nCols % report number of columns available The full specification for this command, including the optional array and column count, is as follows:
All the best,