FreeTDS Development Group

["ZIGLIO, Frediano, VF-IT" <Frediano.Ziglio AT vodafone.com>]

> 
> ZIGLIO, Frediano, VF-IT wrote:
> > Perhaps structure should be changed? Should we remove row 
> concept (dblib
> > already save cur_size so it can save data, data_free too) 
> ?? Handle like
> > blobs?? In this case is_blob_type macro is not sufficient 
> or we should
> > add some new types (not server ones, XSYBVARCHAR have a 
> limited maximun
> > or not depending on column_size). 
> 
> Unless we find a good reason not to, I think we should treat 
> varchar(max)
> like TEXT when fetching.   
> 
> >From an API point of view, the two are the same.  The column 
> can be 2 GB,
> so the application cannot allocate a buffer to hold the whole 
> thing.  It
> will have to be able to read/write in chunks, just like TEXT.  
> 
> The only difference is on the server.  That's not a reason to 
> change the
> client.  
> Does the Microsoft client allow varchar(max) to be a stored procedure
> parameter?  (I bet it does.)  If so, we'll need to add 
> support for it to
> SQLPutData.  
> 
> Of course we'll need to add XSYBVARCHARMAX or something like that.  
> 

This is the problem, there is no XSYBVARCHARMAX but XSYBVARCHAR is 2
byte long for varchar(N) where N <= 8000 while is "chunked" when
column_size is -1...
So is_blob_type does not work. I agree that varchar(max) is a LOB but
has no textptr/timestamp so use TDSBLOB structure waste some space and
confuse programs.

> How does that sound?  
> 

freddy77