On 25 March 2011 17:53, Maciek Sakrejda <msakrejda@truviso.com> wrote:
>> For queries in a transaction, it might make sense to implement this
>> via portals, much as done for fetchsize (i.e. always ask for only 1
>> row initially...
>
> For what it's worth, you don't even need to ask for 1 row. At Truviso,
> we have a layer on top of the driver that asks for 0 rows initially,
> and this works fine (in terms of providing query metadata). There
> *may* be some plans with significant startup overhead where the cost
> of returning zero rows is much less than that of returning one row.
Asking for zero rows from a portal means "give me all the data", though.
Oliver
