On Wed, 9 Mar 2005 09:47:20 +0100, H.Merijn Brand <[EMAIL PROTECTED]> wrote: > On Tue, 8 Mar 2005 12:12:23 -0800, Jonathan Leffler > <[EMAIL PROTECTED]> wrote: > > On Tue, 8 Mar 2005 11:01:48 +0000, Tim Bunce <[EMAIL PROTECTED]> wrote: > > > On Mon, Mar 07, 2005 at 11:47:32PM -0000, Greg Sabino Mullane wrote: > > > > > While I don't have any particular objections, doesn't > > > > > Pg (and most other DBMSs supporting savepoints) have > > > > > SQL syntax to implement them ? If so, isn't just > > > > > > > > > > $dbh->do(<savepoint-sql>) > > > > > > > > > > sufficient ? > > > > > > > > Sure, but they also have syntax to implement BEGIN and ROLLBACK. > > > > It isn't wholly clear why we have $dbh->commit an $dbh->rollback; both > > could be simulated with $dbh->do on most databases. However, there is > > some minor performance advantage on some systems. For example, IBM > > Informix Dynamic Server (IDS) recognizes those statements in ESQL/C > > and the SQLI protocol used to transfer commands between client code > > (such as Perl + DBI) and the server sends a two byte command for > > ROLLBACK instead of sending the string. Further, the two byte command > > does not have to be parsed and executed - so there is a small, but > > barely measurable, performance benefit to using the $dbh->rollback > > statement. > > Uhh, there is much more difference! > I can workaround a lot of database problems in the commit/rollback calls in my > E/SQL code that I could not do unless I would be analyzing every do call
I already got bitten by autocommit (badly; I'm keeping quiet here) - I already *have* to do a load of analysis and other futzing around with every statement. Besides, I can't stop userrs from using $dbh->do() to execute BEGIN WORK, COMMIT WORK or ROLLBACK WORK. Or from preparing and executing them. -- Jonathan Leffler <[EMAIL PROTECTED]> #include <disclaimer.h> Guardian of DBD::Informix - v2003.04 - http://dbi.perl.org "I don't suffer from insanity - I enjoy every minute of it."
