SQL Server Trace file create unique identifier for field TextData of type NTEXT -

to analyse imported trace file have unique value select distinct textdata myimportedtracefile

i tried using hashbyte although not sure if md5 right tool create unique identifier. if case (please tell me if so) still have problem

• using hashbytes('md5', cast(textdata varchar(7999))) textdata_hashbytes cuts few rows of (see reply)

what can create unique identifier every unique value (select distinct textdata ..) in column textdata?

update

based on post dan created testcase

drop table #temp  create table #temp (        int,     b ntext )  insert #temp ( a, b)      select 1, 'some space' union           select 2, ' space' union                   select 3, ' space '  union                      select 4, 'some space   '  union                      select 5, '  space '  union                      select 6, '  space  '   -- returns 6 rows  select        hashbytes('md5', cast(b nvarchar(max)))       , cast(b nvarchar(max)) b #temp;   -- returns 3 rows select newid() uniqueid, b  ( select distinct cast(b nvarchar(max)) b      #temp  ) sq  

these 3 rows result

'  space ' -- 2sp b + 1sp e --> row 5 ' space'   -- 1sp b + 0sp e --> row 2 'some space   ' -- 0sp b + 3sp e --> row 4 

it unclear how row 1 (0sp), 3 (1sp b+e) , 6 (2sp b+e) handled. whitespace removed other not.

you use derived table select distinct:

select newid() uniqueid, textdata (     select distinct cast(textdata nvarchar(max)) textdata     myimportedtracefile     ) uniquequeries;