On 06/17/2013 07:51 PM, Zardosht Kasheff wrote: > +1 on the optimizer tracing. I have found it useful. We've had a > couple of instances where we looked at where an InnoDB query plan and > TokuDB query plan diverge for some query, and it showed us bugs in our > engine. > But as an engine developer you could look into the debug trace as well. The debug trace contains much more info. We noticed that with >4-way joins optimizer trace becomes absolutely useless as one has to look through a huge amount of lines, while with <4-way joins the optimizer related info can be easily extracted from the debug trace. The most important: the optimizer trace does not actually explain WHY the chosen alternative is REALLY better than rejected ones: the calculation of the costs remains under the cover.
Regards, Igor. > Just my $.02. > > -Zardosht > > On Mon, Jun 17, 2013 at 10:37 PM, Igor Babaev <i...@askmonty.org> wrote: >> On 06/17/2013 04:24 PM, Roberto Spadim wrote: >>> hi guys, i was reading mysql 5.6 and 5.7 manual >>> i know that mariadb is very different (a bit) than mysql internally >>> there's a mysql merge issue or something like that i can see what will >>> be merged and what not? >>> >>> i like the partition lock prune, memcache and optimizer tracer of mysql >>> 5.6, but today i'm not using it in mariadb (not a problem, but it's nice >>> features) >> Roberto, >> >> Why do you NEED the optimizer tracer? >> >> Regards, >> Igor. >> >>> >>> -- >>> Roberto Spadim >>> >>> >>> >>> _______________________________________________ >>> Mailing list: https://launchpad.net/~maria-developers >>> Post to : maria-developers@lists.launchpad.net >>> Unsubscribe : https://launchpad.net/~maria-developers >>> More help : https://help.launchpad.net/ListHelp >> >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~maria-developers >> Post to : maria-developers@lists.launchpad.net >> Unsubscribe : https://launchpad.net/~maria-developers >> More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
