Find the length of the longest row in a column in oracle

Question

Does anybody know if there is a way to find what the length of the longest row in a column in Oracle?

Basically I need to get the length of the longest row and then

Answer 1

w/o function:

select 
  rpad(tbl.column_name, length_info.max_length+1, ' ') as target_string
from 
  table_name tbl,
  (
    select max(length(column_name)) max_length 
    from my_table
  ) 
    length_info

with your function:

select 
  rpad(tbl.column_name, MaxLengthFunc + 1, ' ') as target_string
from 
  my_table tbl

declare your function as determinictic for better performance:

create or replace function MaxLengthFunc 
return number  
deterministic
as
  vMaxLen number;
begin

  select max(length(column_name)) 
  into vMaxLen
  from table_name;

  return vMaxLen;

end;