Strange behavior of LENGTH command - ORACLE

Question

I\'ve encountered here an inusited situation that I couldn\'t understand. Nor the documentation of the functions that I will write about has something to light up this thing

Answer 1

The function "nlssort()" return binary with extra 00 at the end of original binary of string.

Testing:

select NLSSORT('abc') from dual

Output:

61626300

this problem can be resolved by removing last 2 digits from NLSSORT's return.

Solution:

  select a, length(a), b, length(b)   
    from ( select 'FGHJTÓRYO DE YHJKS DA DGHQÇÃA DE ASGA XCVBGL EASDEÔNASD' a,
                  replace(
                      utl_raw.cast_to_varchar2( 
                                 substr(nlssort('FGHJTÓRYO DE YHJKS DA DGHQÇÃA DE ASGA XCVBGL EASDEÔNASD', 'nls_sort=binary_ai'),1, 
                                                  length(nlssort('FGHJTÓRYO DE YHJKS DA DGHQÇÃA DE ASGA XCVBGL EASDEÔNASD', 'nls_sort=binary_ai'))-2 
                                                 )
                                          )

                         ,' ','_') b
             from dual
     )

  )