(I think Justin forgot to cc the list, so I'm doing so)... On Thu, Jul 30, 2009 at 2:32 PM, Justin Swanhart<[email protected]> wrote: > With a cost based optimizer, there is always the risk that the stats won't > match the data. > > Are there any plans for a "plan cache"? It would be great to be able to > serialize a plan on my master for a particular query pattern then enforce > that plan for queries that match that pattern on a slave by forcing the > slave to use the plan cache from the master. An analyze on the master would > then provide good plans for all the slaves without having to analyze each > slave. > > Also, storing the statistics in a real I_S metadata table and replicating > them might be an interesting idea too. > > --Justin > > > > > On Thu, Jul 30, 2009 at 10:14 AM, Sheeri K. Cabral <[email protected]> wrote: >> >> On Thu, Jul 30, 2009 at 12:27 PM, Morgan Tocker<[email protected]> wrote: >> >> What experiences have people had with ANALYZE TABLE? Tinkering around >> >> with >> >> it I am wondering if anyone ever uses this with Innodb with any >> >> satisfaction. >> > >> > The unsatisfying thing is that (as Jeremy suggested) the limited >> > sampling makes it error prone. >> > >> > I've met quite a few customers who want to disable automatic >> > resampling because InnoDB keeps switching to sub optimal plans. >> > They'd rather run ANALYZE TABLE manually (or schedule a cron job), so >> > they can be on hand when it screws up. >> > >> > See http://bugs.mysql.com/bug.php?id=26598 and >> > http://www.bigdbahead.com/?p=135 >> > >> > Perhaps the real solution would be to improve the sampling ;) >> >> >> This. ANALYZE TABLE would be great if it actually *worked*. And >> maybe if you could give it options so you could give it some sampling >> information -- we've had issues with different EXPLAIN plans on a >> master and slave, even though we've checked and the data, schema, etc >> is exactly the same. >> >> -- >> - Sheeri K. Cabral >> >> http://tinyurl.com/mysqlbook will take you to the Amazon.com page for >> my book, "MySQL Administrator's Bible". >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~drizzle-discuss >> Post to : [email protected] >> Unsubscribe : https://launchpad.net/~drizzle-discuss >> More help : https://help.launchpad.net/ListHelp > >
-- - Sheeri K. Cabral http://tinyurl.com/mysqlbook will take you to the Amazon.com page for my book, "MySQL Administrator's Bible". _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
