Peter Eisentraut <pete...@gmx.net> writes: > On 11/27/13, 3:47 PM, Tom Lane wrote: >> Given these considerations, I think it'd be better to allow explicit >> application control over whether read-ahead happens for a particular >> query. And I have no problem whatsoever with requiring that the cursor >> be explicitly marked SCROLL or NO SCROLL before read-ahead will occur.
> Well, technically, unspecified means NO SCROLL according to the SQL > standard. A lot of applications in ECPG are ported from other systems, > which might make that assumption. It wouldn't be very nice to have to > change all that. Hm. So you're suggesting that ECPG fix this problem by inserting an explicit NO SCROLL clause into translated DECLARE CURSOR commands, if there's not a SCROLL clause? That would solve the problem of the ECPG library not being sure which behavior applies, but it might break existing apps that were unknowingly relying on a simple cursor being scrollable. OTOH any such app would be subject to breakage anyway as a result of planner changes, so it's hard to complain against this, as long as it's happening in a major version update. I'm for it. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers