[Maria-developers] Fwd: debugging how query plans are made
Is there something similar in MariaDB? ---------- Forwarded message ---------- From: Øystein Grøvlen <oystein.grovlen@oracle.com> Date: Tue, Feb 12, 2013 at 9:11 AM Subject: Re: debugging how query plans are made To: Zardosht Kasheff <zardosht@gmail.com> Cc: "internals@lists.mysql.com" <internals@lists.mysql.com> On 02/12/13 02:54 PM, Zardosht Kasheff wrote:
Hello all,
In MySQL and/or MariaDB, are there any hooks or methods one can use to learn why a query plan is chosen over alternatives? We sometimes notice that a different query plan is chosen for us than InnoDB (which may be fine, given we are a different storage engine), and we would like to better understand why. Is there any debug parameter that gets MySQL to output decisions made in the optimizer?
MySQL 5.6 has optimizer tracing which outputs the decisions made by the optimizer. See http://dev.mysql.com/doc/internals/en/optimizer-tracing.html Hope this helps, -- Øystein
On 02/12/2013 08:10 AM, Zardosht Kasheff wrote:
Is there something similar in MariaDB?
I would recommend you to try this feature first and see how it is helpful for you. May be that after the first your experience you'll lose any interest in it. (The direct answer is: No, we don't have optimizer tracing in MariaDB) Regards. Igor.
---------- Forwarded message ---------- From: Øystein Grøvlen <oystein.grovlen@oracle.com> Date: Tue, Feb 12, 2013 at 9:11 AM Subject: Re: debugging how query plans are made To: Zardosht Kasheff <zardosht@gmail.com> Cc: "internals@lists.mysql.com" <internals@lists.mysql.com>
On 02/12/13 02:54 PM, Zardosht Kasheff wrote:
Hello all,
In MySQL and/or MariaDB, are there any hooks or methods one can use to learn why a query plan is chosen over alternatives? We sometimes notice that a different query plan is chosen for us than InnoDB (which may be fine, given we are a different storage engine), and we would like to better understand why. Is there any debug parameter that gets MySQL to output decisions made in the optimizer?
MySQL 5.6 has optimizer tracing which outputs the decisions made by the optimizer. See http://dev.mysql.com/doc/internals/en/optimizer-tracing.html
Hope this helps,
-- Øystein
_______________________________________________ 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
participants (2)
-
Igor Babaev -
Zardosht Kasheff