a query regarding linker symbol table for global symbols

[dharmendra_rai]

hi
    i have read that linkers use hash table for global symbol table where
symbols hashing to same index in the hash table are put in a linked
list.if the number of symbols  is very large then unless we have a large
table we will have hash-collissions and we will end up having long linked
list per entry in hash table.in this case time-complexity of searching for
a symbol is not of constant order.
        but if we have another hash-table in place of buckets(linked
list) per entry in the hash-table then we can have the searching constant
order.
        could anyone please approve or disapprove this design.
                        thanx
                                Dharmender Rai
                                M.Sc.(Comp.Sc.)
                                Computer Science Department
                                University Of Pune
                                Pune(India)