Jim Starkey wrote: > Jeremy Zawodny wrote: >> On 10/14/08, *Ask Bjørn Hansen* <[EMAIL PROTECTED] >> <mailto:[EMAIL PROTECTED]>> wrote: >> >> >> On Oct 13, 2008, at 10:55, Jim Starkey wrote: >> >> You are right if you think about transaction context. The >> thing is most web shops, almost all, run in autocommit >> mode. This is the 80% case (if not more). Of course when >> you run within the context of a transaction you have an >> issue, I mentioned that in my original email, but the >> majority case does not do this. They fire off seven >> queries, get the results, and then build a page. >> >> >> Gosh, Brian, that's a pretty good argument for an aggregating >> interface. Of course then they would have a single >> transaction and the results would even be consistent. >> >> >> I think that's missing the point a little pushing the >> transactions. :-) Not using transacions isn't just being lazy; in >> many applications most queries can be done safely without >> transactions. Spending any CPU cycles on them would just be wasted. >> >> >> Not to mention disk I/O. >> > Yup, where getting the right answer doesn't matter, non-transactional > engines are the way to go. The historically oriented might point out > that databases were invented to give consistent answers in a volatile > environment, but that was on a parallel universe somewhere.
This isn't about transactional vs. non-transactional or even about getting the wrong answer. For most of these shops, the transactional ability is useful for some of the queries - usually a very small number of them. It's the transaction isolation that's useless for a large number of the queries. (Or, to be clear, keeping the same transactional context for the purposes for isolation - I'm sure that no one wants the underlying data to change out from under a single query) So if one query gets one set of data (say, the address for "The Ivy" on that page Ask sent) and another query gets something else (say, the list of accepted payment methods) ... if someone in an admin interface changed the list of payment methods after the address query was run but before the payment methods query - NO ONE cares. Keeping context is honestly retarded. The funny thing is that some of the stuff built for the purposes of transactions (MVCC etc) are actually quite useful for these folks. (One of the main reasons no one really uses MyISAM any more) Just not all of it. Monty _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
