PostgreSQL incorrect sorting

Question

I use PostgreSQL 9.3.3 and I have a table with one column named as title (character varying(50)).

When I have executed the following query:

select *         


        

Answer 1

It seems, that when sorting Oracle as well as Postgres just ignore non alpha numeric chars, e.g.

  select '*' 
   union all
  select '#' 
   union all
  select 'A'
   union all
  select '*E'
   union all
  select '*B'
   union all
  select '#C'
   union all
  select '#D'
order by 1 asc

returns (look: that DBMS doesn't pay any attention on prefix before 'A'..'E')

  *
  #
  A
  *B
  #C
  #D
  *E

In your case, what Postgres actually sorts is

'', 'A' and 'Example'

If you put '#' in the middle od the string, the behaviour will be the same:

  select 'A#B'
   union all
  select 'AC'
   union all
  select 'A#D'  
   union all
  select 'AE' 
order by 1 asc

returns (# ignored, and so 'AB', 'AC', 'AD' and 'AE' actually compared)

  A#B
  AC
  A#D
  AE

To change the comparison rules you should use collation, e.g.

  select '#' collate "POSIX"
   union all
  select 'A' collate "POSIX"
   union all
  select '#Example' collate "POSIX"
order by 1 asc

returns (as it required in your case)

  #
  #Example
  A