Actually, I rather like this idea too. I can imagine a version that's:
(1) smart enough to ignore SQL comments (some folks stick a comment at the end of the query with a unique host Id or something for stats and/or debugging) (2) configurable so the site can decide they don't care about transaction state and is willing to say that 2 queries are duplicates if the match a very small set of features (user makes sense, but not sure about tx isolation level and other "exotic stuff") The reason I suggest a "related" approach to seeing that two queries are equal is that I bet most folks doing high volumes of possibly duplicate queries are not doing much fancy in the first place. They're just hitting a bank of slaves from their webbies and hoping to repopulate the failed memcache tier without killing the DB boxes i n the process. Or am I nuts? Jeremy On Fri, Jun 25, 2010 at 3:17 PM, Roland Bouman <[email protected]>wrote: > It's an interesting idea! > > I think it could be quite hard to detect whether the same query will > in fact deliver the same result though - one would have to check to if > the query is affected by the state of the session (values of > session-scoped variables, functions returning session-dependent data > like current_user(), isolation level of an explicit transaction, > probably a lot more things). > > (of course - i am not a drizzle dev or engineer - I may be > overestimating the complexity) > > > On Fri, Jun 25, 2010 at 3:05 PM, Brian Moon <[email protected]> wrote: > > So, one common use for Gearman seems to be running SQL queries through it > so > > that a given query only ever is running once at a given time. This solves > > one big issue I have seen with a cache stampede. The application servers > all > > run the same queries at the same time. Pushing this logic down to the > > database server seems like a good idea from where I sit. The server could > > recognize that there are N connections all running the same query and not > > try and do all the work needed to send back the result. > > > > What do you guys think? Does this make sense at the database layer? Is > the > > drizzle plugin architecture able to support this type of behavior? > > > > -- > > > > Brian. > > -------- > > http://brian.moonspot.net/ > > > > _______________________________________________ > > Mailing list: https://launchpad.net/~drizzle-discuss > > Post to : [email protected] > > Unsubscribe : https://launchpad.net/~drizzle-discuss > > More help : https://help.launchpad.net/ListHelp > > > > > > -- > Roland Bouman > blog: http://rpbouman.blogspot.com/ > twitter: @rolandbouman > > Author of "Pentaho Solutions: Business Intelligence and Data > Warehousing with Pentaho and MySQL", > http://tinyurl.com/lvxa88 (Wiley, ISBN: 978-0-470-48432-6) > > Author of "Pentaho Kettle Solutions: Building Open Source ETL > Solutions with Pentaho Data Integration", > http://tinyurl.com/33r7a8m (Wiley, ISBN: 978-0-470-63517-9) > > _______________________________________________ > Mailing list: https://launchpad.net/~drizzle-discuss > Post to : [email protected] > Unsubscribe : https://launchpad.net/~drizzle-discuss > More help : https://help.launchpad.net/ListHelp >
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