On Fri, Mar 02, 2012 at 11:41:05AM -0500, Noah Misch wrote: > We yet lack a consensus on whether native ECPG apps should have access to the > feature. My 2c is to make it available, because it's useful syntactic sugar. > If your program independently processes each row of an arbitrary-length result > set, current facilities force you to add an extra outer loop to batch the > FETCHes for every such code site. Applications could define macros to > abstract that pattern, but this seems common-enough to justify bespoke > handling. Besides, minimalists already use libpq directly.
Sorry, I don't really understand what you're saying here. The program logic won't change at all when using this feature or what do I misunderstand? > I suggest enabling the feature by default but drastically reducing the default > readahead chunk size from 256 to, say, 5. That still reduces the FETCH round > trip overhead by 80%, but it's small enough not to attract pathological > behavior on a workload where each row is a 10 MiB document. I would not offer > an ecpg-time option to disable the feature per se. Instead, let the user set > the default chunk size at ecpg time. A setting of 1 effectively disables the > feature, though one could later re-enable it with ECPGFETCHSZ. Using 1 to effectively disable the feature is fine with me, but I strongly object any default enabling this feature. It's farily easy to create cases with pathological behaviour and this features is not standard by any means. I figure a normal programmer would expect only one row being transfered when fetching one. Other than that, thanks for the great review. Michael -- Michael Meskes Michael at Fam-Meskes dot De, Michael at Meskes dot (De|Com|Net|Org) Michael at BorussiaFan dot De, Meskes at (Debian|Postgresql) dot Org Jabber: michael.meskes at googlemail dot com VfL Borussia! Força Barça! Go SF 49ers! Use Debian GNU/Linux, PostgreSQL -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
