On Fri, 2013-05-10 at 10:40 -0700, Paul McNett wrote:
> 
> However, I've been cautioned that not all database backends support sending 
> one
> record at a time like they are supposed to.
> 
> Anyway, I'd love to get this figured out but have nothing to offer at the 
> moment.

I'm not sure there is any requirement for this, particular if the is a
an "order by" relation in the SQL then the SQL engine my have to fetch
all records from the backing store, before in can determine which is the
first to return to the client.  Depending on your architecture, it is
entirely possible that fetching records from the backing store is the
slowest step.

I do have a solution though, for the case the where limiting factor is
the bandwidth between client and server, in these case you can do the
query to 2 stages, the first one produces and order list of primary
keys, then you can individually fetch each each record by Pkey in a
separate query. I've got this implemented as wrapper around the old
wxDbTable class (in wxWidgets /C++) but that probably bit rotten now.

Unfortunately one of the biggest factors I'm seeing at the moment is
that with Python/MySQL there is a huge overhead in each SQL query
issued, so even the above trick has to be used with caution.

-- 
Roger Gammans <[email protected]>
_______________________________________________
Post Messages to: [email protected]
Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/dabo-users
Searchable Archives: http://leafe.com/archives/search/dabo-users
This message: 
http://leafe.com/archives/byMID/[email protected]

Reply via email to