[freetds] problems storing more than 8000 bytes of data in a varchar(max) column

Bob Hetzel beh at case.edu
Fri Aug 17 13:46:18 EDT 2007


There's actually a big plus side to the varchar(max) field type however. 
  It also gets around a limitation in record size.  Previously, changing 
to text fields was required so your record wouldn't go past a page 
limit, not as well as to allow 1 big field in a record.  However, that 
had limitations on how you could search.  The varchar(max) field type 
removes those limitations.  Too bad they didn't just figure out a way to 
extend the varchar datatype seamlessly, but I guess db engine designers 
like to help keep dba's employed.  :)

   Bob

James K. Lowden wrote:
> Moritz Bunkus wrote:
>> But the MS
>> SQL Server 2005 documentation states in various places that "text" type
>> columns are deprecated and will be removed in future versions. It
>> suggests using the column type "varchar(max)"
> 
> Ah, I see.  I hadn't come across that yet, thanks.  
> 
> FWIW, I wouldn't worry too much about deprecation announcements.  There
> are a lot of databases and software out there that use TEXT.  It will take
> years to do away with it.  
> 
> I guess it was 10 years ago Microsoft deprecated db-lib.  First they
> warned us about it, then they stopped updating it, then they stopped
> including it, then they dropped the documentation.  But it still works. 
> We've also been told for years not to use the system tables, to rely
> instead on the information schema views.  Except the only place some
> things can be found is in the system tables and -- wouldn't you know it?
> -- that's what Microsoft's own procedures use.  
> 
> Also, sometimes the advice about the future changes before the future
> arrives.  There've been some dead ends.  Don't get me started about
> SQL-DMO.  And then there are the unwarned-about changes, like substituting
> 'sys' for 'dbo' and changing the optimizer in ways that made some
> pre-existing queries run slow.  However hard you work to prevent problems
> with future releases, there will always be some.  
> 
> My policy is to use what I know and take advantage of new features when
> they're helpful.  If and when the day comes that Microsoft says not "in
> future versions" but "in the next version", you'll know it's time to the
> big search-and-replace.  
> 
> BTW, if you do use DBD::Sybase, be advised placeholders don't work.  They
> can't, because of the way they're defined in ct-lib.  
> 
> Regards,
> 
> --jkl
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