FreeTDS Development Group

["James K. Lowden" <jklowden AT schemamania.org>]

On Mon, 3 Mar 2003 17:45:46 -0800, "Anwar, Mohammed"
<mohammed.anwar AT intel.com> wrote:
> 
> I was wondering what is the best way to implement bulk updates.
> I have a large number of updates to do.
> 
> One way is to use "instead of" triggers,  but is this a good way ?

Well, it's not a FreeTDS question, but OK.  

Definitely don't use triggers.  

I take it you have a bunch of rows in a table, and a file consisting of
updated information for those rows.  The least-effort technique is:

1.  create a table suitable for bulkloading your file.  
2.  Use freebcp to load that table.
3.  "update tgt from src set data = src.data where tgt.key = src.key".

If you have more than, say, 100,000 rows to do, you might want to put #3
in a loop and limit the transaction size that way.  The maximum reasonable
transaction size is determined by the hardware, and to some extent by the
row size.  

If any of the above is unclear, ask again.  :-)

--jkl