With the optional specification of an integer expression (Expr) in a fetch-set statement, you can restrict the number of rows to be fetched to Expr rows. The last row of the restricted result set is the last row fetched by a previous sequential fetch-next or fetch-all statement. The first row of the restricted result set is calculated as follows:
first row in restricted result set := maximum(1, last row number sequentially fetched - Expr)
Thus fetch-set statements with the Expr option are only useful in conjunction with sequential fetch-next statements.