June 2013 - developers - lists.mariadb.org

[Maria-developers] review / close MDEV-4581
by Roberto Spadim 18 Jun '13

18 Jun '13

hi guys, could review / close MDEV-4581<https://mariadb.atlassian.net/browse/MDEV-4581> ? -- Roberto Spadim

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[Maria-developers] Implementing implicit primary key in mysql server
by Lixun Peng 18 Jun '13

18 Jun '13

Hi, As we know, InnoDB has implicit primary key if a table hasn't defined a primary key. However MySQL server doesn't know this primary key, so this primary key will not apear in binlog. When we are using ROW format binlog for replication, if a table has no any indexes, that's a disaster. If a table without indexes do a DML (UPDATE/DELETE), of course it will run a long time in master, but in slave, it still need a long time. It will cause serious slave replication delay. For example: binlog_format=ROW; CREATE TABLE table1 ( col1 varchar(32), col2 int ); table1 hasn't any indexes, if table1 has 100 million rows, I do a query "UPDATE table1 SET col1='xxx' WHERE col2=100", and this query will effect 1 million rows. Then it has 1 million UPDATE events in binlog. After slave received these events, each events should scan all rows!!! It will cause serious replication delay! I saw:https://kb.askmonty.org/en/row-based-replication-with-no-primary-key/ But if no any indexes, it still a problem. I think mysql server can do the same thing as InnoDB do, if user doesn't define the primary key, mysql can add the primary key automatically. For example: If user create a table like "table1", we can do "ALTER TABLE table1 ADD __id bigint auto_increment, ADD PRIMARY KEY(__id)", so in fact, the "table1" structure is CREATE TABLE table1 ( col1 varchar(32), col2 int, __id bigint auto_increment primary key ); But when user do "SELECT * FROM table xxx" or "INSERT INTO table VALUES(xx)", we should ignore implicit primary key, "__id" will not apear in the result set. How do you think? Thanks, Lixun -- Senior Database Engineer @ Taobao.com Mobile Phone: +86 18658156856 (Hangzhou) Gtalk: penglixun(at)gmail.com Twitter: http://www.twitter.com/plinux Blog: http://www.penglixun.com

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[Maria-developers] close some mdev
by Roberto Spadim 17 Jun '13

17 Jun '13

hi guys could anyone close some opened and fixed (won't fix) mdev's ? the comment explain why to close it 1. MDEV-4571 <https://mariadb.atlassian.net/browse/MDEV-4571> 1. MDEV-4583 <https://mariadb.atlassian.net/browse/MDEV-4583> 1. MDEV-4589 <https://mariadb.atlassian.net/browse/MDEV-4589> 1. MDEV-575 <https://mariadb.atlassian.net/browse/MDEV-575> -- Roberto Spadim SPAEmpresarial

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Re: [Maria-developers] Jira new field
by Roberto Spadim 17 Jun '13

17 Jun '13

ok =) thanks 2013/6/17 Sergei Golubchik <serg(a)mariadb.org> > Hi, Roberto! > > On Jun 17, Roberto Spadim wrote: > > > > today i'm 'working around ' this, and putting the 'group information' in > > MDEV issue, example.. query cache things i put > > QUERY CACHE - some issue title > > processlist things i put > > PROCESSLIST - some issue title > > > > this works too, but well. mariadb team can change and when i lost my > memory > > (some times =) ) i need to read all issues again and find where i put the > > information > > You can certainly add labels like QUERY CACHE and PROCESSLIST. This > shouldn't be a problem. > > Regards, > Sergei > -- Roberto Spadim SPAEmpresarial

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Re: [Maria-developers] Jira new field
by Roberto Spadim 17 Jun '13

17 Jun '13

heeh sometimes i just add a label that don't have interest to mariadb team, it's just to 'group' my issues if there's a interesting and nice way to do this could be nice it's just to organize my issues and when i have time see what changed and where, not changing the work of mariadb placing the right label in the right issue 2013/6/17 Sergei Golubchik <serg(a)mariadb.org> > Hi, Roberto! > > On Jun 17, Roberto Spadim wrote: > > hi guys, could we add a Reporter Label inside jira issue? instead of only > > Label (used by mariadb team) > > it's easier to filter issues, thinking about the reporter filter not for > > mariadb team filters > > But you can add your labels to the Label field, why would one need > another list of Labels? > > Regards, > Sergei > -- Roberto Spadim SPAEmpresarial

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[Maria-developers] Jira new field
by Roberto Spadim 17 Jun '13

17 Jun '13

hi guys, could we add a Reporter Label inside jira issue? instead of only Label (used by mariadb team) it's easier to filter issues, thinking about the reporter filter not for mariadb team filters -- Roberto Spadim

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[Maria-developers] Is it possible to export last seen GTID from IO thread?
by Pavel Ivanov 15 Jun '13

15 Jun '13

Kristian, We had an idea that can make master failovers much easier, please could you tell us how feasible to do that in MariaDB. Currently when master dies and failover is necessary we have to wait while SQL thread catches up with IO thread on all replicas before we'll be able to decide which replica should be new master. Otherwise we can loose some transactions. But if IO thread could export some variable indicating which GTID it's seen last then we'll be able to understand which replica is furthest in replication stream faster, without waiting. Of course for multi-domain replication it will be more complicated and IO thread will have to synthesize gtid_slave_pos which server would have after applying all relay logs. But exporting this synthesized position will still help a lot. So what do you think? Is it possible to do this in MariaDB? Thank you, Pavel

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Re: [Maria-developers] Process suggestion for minor issues
by Elena Stepanova 14 Jun '13

14 Jun '13

(warning: it's a long one) Hi Sergei, On 6/14/2013 6:26 PM, Sergei Golubchik wrote: > Hi, Elena! > > On Jun 14, Elena Stepanova wrote: >> On 6/14/2013 2:27 PM, Rasmus Johansson wrote: >>> Here is a suggested process to handle the ever growing amount of >>> minors. If a minor issue isn't fixed after two consecutive releases >>> it's re-reviewed and either priority changed to major (or higher), >>> or the minor issue is closed with resolution Won't Fix and a >>> comment. Example of comment can be that "this is an edge case where >>> effort and benefits doesn't correlate". >> >> I don't think the algorithm is quite fair. It means that if a really >> minor bug happens to be found during a relatively slow period, it gets >> fixed, but another bug, even considerably more important (but still >> falling into "not major => minor" category), can be by this time closed >> as "not worth fixing" just because people had been busy with some other >> stuff and couldn't fix it over two previous releases; while logically, >> if somebody suddenly has time to fix a minor bug, the latter should be >> fixed first. > > This algorithm has a "re-reviewed and either priority changed to > major..." step, so it's not just the timing. Not like automatic closing > of old bugs. Yes, I got that part; but it doesn't change the potential faulty result. Lets say we have imaginary priorities 1-5 which are all "minor", 1 being the lowest. For a while you had had a bug of "priority 4". After 2 releases the reviewing force reviewed it, decided it was minor (rightly so), and closed it. A few days later you got a bug of "priority 1". A few more days later you suddenly have time to fix a bug -- you are stuck at your main task and need a distraction, or you've got a headache and can't work on anything serious, or you only have half an hour before you need to go pick up kids... whatever. Naturally, you go to the list of your open bugs, take a quick look and pick whatever fits. If you still had the bug of priority 4, you'd fix it now, but instead you fix the bug of priority 1. I don't know about others, but I do keep a bunch of open low-priority tasks, and while rarely, sometimes it happens that I can do something about a minor one. And then I look at them and pick by importance and "suitability for the moment", not by the creation time. > >> I'm fine with closing bugs as "Won't Fix", but imho it should be based >> on the merits of the bug itself, not on the bad timing of its >> creation. Since all our developers are very senior and can totally >> make such a decision on their own, I suppose anyone who a bug is >> assigned to can take a look at it and either close it as "Won't fix" >> with a proper explanation, regardless the timing (even right after >> receiving it), or keep it open. > > The main issue I didn't like - what that algorithm is making an attempt > of solving - is a growing pile of minor bugs that we aren't going to > fix. I agree, there is no point at keeping those that we are really not going to fix. But I don't see anything critically bad at preserving those that we *want* to fix, just currently don't have time to -- as long as we don't schedule them for the closest release, thus lying to users and to ourselves (more on that later). I also think it's two essentially different categories. Later here you are saying that "a closed bug can always be reopened later and fixed". If we put the "don't have resources to fix" bugs into the same trash bin as we currently use for "really won't fix" bugs, re-opening will never happen. Who will go through the whole bunch of "Won't fix" bugs, review them *again* and see if they are really not worth fixing, or if we had to close them because we didn't have resources? Certainly you can't do it when you just have little time to fix one-two small bugs, you'll spend more time searching. > > A bug is real, so it's difficult to say "won't fix", it's much easier, > psychologically, to say, "okay, I'll fix it, *when I have time*". But > really, for minor bugs this might never happen. But sooner or later somebody who's reviewing them will dare close it anyway?.. Okay, I agree that psychologically it is easier to reject a bug *together with somebody* than make such a decision on your own, group mentality and all that, I get it and have it myself; so if it's all about having some kind of committee for closing such bugs, let it be. (I don't really know who could this committee consist of. Generally, I'm a big supporter of a triage team, it makes the process less personal. But in a company where everyone is pretty much unique in his area, it's a bit strange, because at the end only the expert can bring in an educated verdict -- and this would normally be the person the bug is already assigned to anyway; others will just be there to hold his hand.) > And de-facto this leads to wrong expectations (users believe the bug > will be fixed in a specific version, but it isn't) and us lying to our > users. True, but I think the new approach will mess up more than it will fix. Now we have Fix version evolution like that: 5.5.30 => 5.5.31 => 5.5.32 => 5.5.33 => .... It's bad. I still think that we shouldn't schedule minor bugs for any particular version. We've discussed it before, and yes, I know that we do it to keep them on somebody's radar, but I would think that having it assigned to somebody should be enough, since it's already on a radar of the person who it's assigned to. But maybe I'm wrong and nobody looks at lists of bugs assigned to them -- shouldn't we try to change it instead, then? But with the new system, we will have 5.5.30 => 5.5.31 => "Won't fix, it isn't worth it". If I were a user, now I'd be mad. If it isn't worth fixing, why didn't you say so right away? Why schedule it and even move it to the next release then? That's even more of lying to users than we currently do, and in a more irritating way. > My idea is to be honest about it, and if we don't have resources to fix > a specific bug, we won't drag it forever from one release to another, > but close it eventually. I agree. But I think we shouldn't even start dragging it then. If you are going to have a committee which would regularly review bugs (those that have waited for 2 releases) and decide if they're worth fixing or not, why not do it right away -- let the same committee decide it for *new* bugs instead, so that unimportant ones don't even get scheduled and go to the trash bin immediately. It will spare users wrong expectations. > And yes, I hate closing non-fixed bugs too. > > If you can suggest another solution, please do. But "keep it open" > doesn't work, as we've seen already. Well, I'd suggest to consider adjusting yours a little, in the following way: - define who will be reviewing the bugs; - those person(s) will screen new bugs instead of those that have waited for 2 releases; - , set "Won't fix" when we really mean it (example: PBXT bugs, etc.), and create a new resolution "Don't have time to fix" or "Wishlist" or whatever, and put corresponding bugs there, while keeping them assigned. The last point is to preserve at least hypothetical possibility for the bugs to be re-opened later. So, if somebody has time to fix a minor bug, first he looks at the list of his open bugs (we already know that the committee kept only most worthy ones there). If nothing fits the moment, or (a miracle!) the list is empty, the somebody goes to the "wishlist" bugs assigned to him, and picks from there. At the same time, those bugs aren't shown as open, aren't scheduled for any particular release, the users aren't misled, etc. A couple more notes: - I think external bugs should generally have higher priority than otherwise equal ones found internally; - a different approach might be needed for bugs in new feature trees, it should be decided separately (the basic question is -- when we consider the feature good enough to be pushed to the main tree, whether it requires fixing minor bugs or not). /E > > Besides, a closed bug can always be reopened later and fixed. > > Regards, > Sergei >

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[Maria-developers] Process suggestion for minor issues
by Rasmus Johansson 14 Jun '13

14 Jun '13

Hi MariaDB Developers, This is a suggestion on how to deal with minor or lower priority bugs and tasks in JIRA, http://mariadb.org/jira . Currently, the process we use makes a clear differentiation between major or higher prioirty issues (called majors altogether after this) and minor or lower priority issues (called minors altogether after this). The majors are the ones that should be fixed for a release and the minors are rolling, meaning that they are done when the corresponding developer has finished his/her majors. This of course sounds logical, but it also leads to a growing number of minors for every consecutive release, many of them which never will be fixed but in the current process will hang around. Here is a suggested process to handle the ever growing amount of minors. If a minor issue isn't fixed after two consecutive releases it's re-reviewed and either priority changed to major (or higher), or the minor issue is closed with resolution Won't Fix and a comment. Example of comment can be that "this is an edge case where effort and benefits doesn't correlate". It should also be noted that after closing an issue in JIRA, it doesn't mean that it disappears. It will still show up in free text searches and among the issues for the version where it was closed. Please provide your thoughts. Do you think it's an OK way to deal with the minors or do you prefer some other way? Best regards, Rasmus

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Re: [Maria-developers] Review request: mdev-4635
by Alexander Barkov 14 Jun '13

14 Jun '13

Hi Sergei, On 06/14/2013 04:30 PM, Sergei Golubchik wrote: > Hi, Alexander! > > On Jun 13, Alexander Barkov wrote: >> On 06/13/2013 08:16 PM, Sergei Golubchik wrote: >>> >>>> === modified file 'mysql-test/r/strict.result' >>>> --- mysql-test/r/strict.result 2011-06-05 02:56:06 +0000 >>>> +++ mysql-test/r/strict.result 2013-06-13 12:15:43 +0000 >>>> @@ -213,11 +213,11 @@ ERROR 22007: Incorrect date value: '2004 >>>> INSERT INTO t1 (col1) VALUES(STR_TO_DATE('0.10.2004 15.30','%d.%m.%Y %H.%i')); >>>> ERROR 22007: Incorrect date value: '2004-10-00 15:30:00' for column 'col1' at row 1 >>>> INSERT INTO t1 (col1) VALUES(STR_TO_DATE('31.9.2004 15.30','%d.%m.%Y %H.%i')); >>>> -ERROR 22007: Incorrect date value: '2004-09-31 15:30:00' for column 'col1' at row 1 >>>> +ERROR HY000: Incorrect datetime value: '31.9.2004 15.30' for function str_to_date >>> >>> Hmm, I don't know. I liked the old error message more. >>> Indeed, datetime value '31.9.2004 15.30' is just fine for a function str_to_date(). >>> But '2004-09-31 15:30:00' is not fine for column 'col1' in the strict mode. >>> >>> Why did that change? >> >> Before the change the warning was generated in >> Field_timestamp::store_TIME_with_warning. >> >> Now this warning is generated much earlier, >> in Item_func_str_to_date::get_date(), >> after check_date() is called. > > Which, I think, it wrong. The date is perfectly ok, as far as > STR_TO_DATE is concerted, it's wrong for a field. > >> The problem was that Item_func_str_to_date: >> a. checked TIME_NO_ZERO_DATE >> b. did not check TIME_NO_ZERO_IN_DATE (the bug) >> c. did not check invalid dates >> >> After the patch it: >> >> a. checks TIME_NO_ZERO_DATE >> b. checks TIME_NO_ZERO_IN_DATE >> c. checks invalid dates >> >> I thought it would be good to check everything, >> for consistency. But a side effect is a different warning. > > I agree, it should check everything. But, perhaps, the field should not > pass TIME_NO_ZERO_DATE|TIME_NO_ZERO_IN_DATE down to the arg->get_date() ? It does not. The above warnings are not about zeros. They are about wrong dates: for example, there is no September 31, like in '31.9.2004 15.30'. The last version of the patch does not change the warnings. It works as follows: - str_to_date checks TIME_NO_ZERO_DATE and TIME_NO_ZERO_IN_DATE with help of check_date(), but only if the caller wants it (CONVERT_TZ wants, field does not). - str_to_date suppresses checking of invalid dates inside check_date() and leaves this responsibility to the caller (like it was before the patch). If we want check invalid dates inside check_date() in str_to_date, then this warning "Incorrect date value: '2004-09-31 15:30:00' for column 'col1' at row 1" won't be possible, because str_to_date does not know the name of the column it's being inserted into. But we could try to produce something like this: "Incorrect datetime value: '2004-09-31 15:30:00'" I.e. a better formatted value, but without the column name. > > Regards, > Sergei >

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