I don't claim we will necessarily need it! :-) I was only asking. No more comments at the moment. I will update here if I think I have a reason to!
Thanks for considering! -- Peter On Sun, Sep 30, 2012 at 7:13 PM, Igor Babaev <i...@askmonty.org> wrote: > Peter, > > You are right that EXPLAIN in any format has nothing to do with the > optimizer. Looking at the piece of the MySQL code that forms the strings > for the EXPLAIN anyone could easily come up with the patch providing > JSON format for the EXPLAIN (even with the extensions of MySQL 5.6) and > it would take him/her 2-3 days at most (maybe even a few hours). > > That's why we are reluctant to pull the existing implementation of JSON > format from MySQL 5.6 into MariaDB. The patch is huge and overburdened > with unneeded complexities. Besides it contains a lot of "restructuring" > code that has nothing to do with the feature itself. > > Personally I think that the content in the current EXPLAIN (including > the content of the EXPLAIN EXTENDED) is so shallow that any graphical > representation hardly can help it (compare it, for example, with the > info provided by MS SQL server). > > If, nevertheless, you badly need the feature and is ready to co-sponsor > the feature (together with MP AB) we could discuss the details of the > possible simple implementation. And of course we will support it in > MariaDB if anybody else provide us with a patch for such an implementation. > > Regards, > Igor. > > On 09/30/2012 04:23 AM, Peter Laursen wrote: > > I do not see why this should be a concern for the optimizer team. > > > > The output from EXPLAIN (in any format) does not affect optimizer's > > operation but only provides information of *optimizer result*. The > > format chosen is (?) applied is *after* not *before* or *during* the > > optimization process. > > > > TRADITIONAL EXPLAIN returns the result as an **array**. JSON EXPLAIN > > returns the result as a single (Json-formatted) **string** (not unlike > > SHOW ENGINE INNODB STATUS, btw). But both should have exactly the same > > information - and if they don't it is a bug with JSON EXPLAIN in MySQL > > 5.6 IMO. > > > > But as I am not well-versed in server internals, I could have > > ovelooked/misunderstood something, of course. > > > > -- Peter > > > > On Fri, Sep 28, 2012 at 5:18 PM, Peter Laursen <peter_laur...@webyog.com > > <mailto:peter_laur...@webyog.com>> wrote: > > > > @wlad is completely right! > > > > Workbench introduced a Visual Explain based on JSON EXPLAIN as > > Blogged here: > > http://www.arubin.org/blog/2012/09/26/mysql-visual-explain/ > > > > The very reason why JSON EXPLAIN was introduced in MySQL 5.6 could > > be that Oracle develops the server and tools (WB, Enterprirse > > Monitor primarily) in parallel. Some recently introduced features > > in the server could be introduced for the primary reason that they > > should be 'exploited' by MEM and/or WB. JSON EXPLAIN is one. > > Another example is the Performance_Schema table introduced in 5.6.6 > > (I don't remember the table name) that records an 'aggregated > > summary' of queries' performance. Actually this table has about the > > same information as what MONyog 'Query Analyzer' module displays in > > its most simple display mode (but MONyog can be 'drilled down' to a > > more detailed view). > > > > So Oracle *thinks* the server and their most important tools *as a > > whole*, I think. We/Webyog cannot ignore this, as we compete with > > Oracle (SQLyog <-> WB, MONyog <-> MEM). We have to consider to > > implement a more intuitive and advisory way of displaying EXPLAIN > > results (for non-expert users primarily of course). The JSON format > > is interesting for us in the context. > > > > -- Peter > > > > > > > > > > > > On Fri, Sep 28, 2012 at 4:50 PM, Vladislav Vaintroub > > <w...@montyprogram.com <mailto:w...@montyprogram.com>> wrote: > > > > > > > > > -----Original Message----- > > > From: maria-discuss- > > > bounces+wlad=montyprogram....@lists.launchpad.net > > <mailto:montyprogram....@lists.launchpad.net> [mailto:maria- > > <mailto:maria-> > > > discuss-bounces+wlad=montyprogram....@lists.launchpad.net > > <mailto:montyprogram....@lists.launchpad.net>] On Behalf > > > Of Michael Widenius > > > Sent: Freitag, 28. September 2012 16:04 > > > To: Peter Laursen; i...@askmonty.org > > <mailto:i...@askmonty.org>; tim...@askmonty.org > > <mailto:tim...@askmonty.org>; > > > pser...@askmonty.org <mailto:pser...@askmonty.org> > > > Cc: Maria Discuss; Maria Developers > > > Subject: Re: [Maria-discuss] [Maria-developers] Json Explain > > > > > > > > > For the moment we don't have a plan for that. > > > > > > The main reason is that the MariadB optimizer people don't > > like the > > > implementation and we are not sure how useful the current > output > > > really is. > > > > > > > I guess json is not for normal people to read , it is for > > programs to > > analyze and ,for example, display in a visually pleasing > > fashion. I believe > > this is the reason why Peter asks, and (I guess) the reason why > > Workbench > > has visual explain feature now for 5.6+. > > http://www.arubin.org/blog/2012/09/26/mysql-visual-explain/ > > > > > > > >
_______________________________________________ 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