- developers - lists.mariadb.org

[Maria-developers] ALTER ONLINE TABLE syntax
by Sergei Golubchik 18 Aug '13

18 Aug '13

Hi, You've added this ALTER ONLINE TABLE syntax, where ONLINE de facto means "without copying the data". Now, after 5.6 merge we also have ALGORITHM=COPY|INPLACE and LOCK=NONE|SHARED|EXCLUSIVE. I've mapped ONLINE to ALGORITHM=INPLACE, because that's what it means. But it's confusing, one can have an "inplace" operation under an exclusive lock, if the engine wants it that way. And it won't be "online" by any stretch of imagination. One can also technically have a "copy" operation with a very permissive write-allow-write lock, and it'll be as online as one can get it. I mean, logically ONLINE should mean LOCK=NONE, not ALGORITHM=INPLACE. But that would change the existing behavior and the test results too. For example, *any* ALTER on the temporary table would always be "online", because, well, it wouldn't take any lock on that table. Alternatively, we can keep ONLINE as ALGORITHM=INPLACE, and deprecate it, issue a warning, suggesting to use the new 5.6 syntax. Opinions? Regards, Sergei

5 7

[Maria-developers] MDEV-4916
by Roberto Spadim 18 Aug '13

18 Aug '13

Patch uploaded, and test work (but i didn't add a unit test yet :/ sorry i don't know yet how to write it) -- Roberto Spadim

1 0

[Maria-developers] Joining the team
by Esteban Orduno 17 Aug '13

17 Aug '13

Hi, all: I would like to contribute to the maria-db team. Who can I talk iniatially to get some type of orientation about it? Esteban Orduno

2 1

[Maria-developers] More Secure Kill Command
by Roberto Spadim 17 Aug '13

17 Aug '13

Hi guys i was mailing at maria-discuss, but i think it a new feature, and want some view point from developers... check this problem: connection 1) big select... connection 2) show processlist connection 1) other query connection 2) kill connection 1 id (i take +- 1 second between show processlist and this command) connection 1) killed the problem? the kill connection 1 (KILL thread_id) killed the wrong query could we implement something like: KILL [CONNECTION | QUERY] thread_id [QUERY "some relative unique query id in this database"] the relative unique query id, could be: substr(sha1 or md5 of (thread_id + query start time),0,6) (6 hex numbers is good?) it's like a git small hash commit id, maybe we could make it more unique... but since i will not use it very often, i think a less intensive work is nice here... a global query id could add more one lock for every query... example: KILL 1 QUERY "abcdef" the "abcdef" = substr(MD5( thread id + query start time ),0,6) we could add client ip or others unique information about this query, but something that don't increase (ok just a little) the load of a show processlist / select * from information_schema thanks -- Roberto Spadim

4 7

[Maria-developers] MariaDB 10.0.4 Release Prep
by Daniel Bartholomew 16 Aug '13

16 Aug '13

All, I've begun prep work for the MariaDB 10.0.4 release. Draft Release Notes and Changelogs are here: - https://kb.askmonty.org/en/mariadb-1004-release-notes/ - https://kb.askmonty.org/en/mariadb-1004-changelog/ Please let me know ASAP if anything needs to be added/changed/etc... Thanks. -- Daniel Bartholomew Google+ - http://gplus.to/dbart Twitter - http://twitter.com/daniel_bart MariaDB: An Enhanced Drop-in Replacement for MySQL Website - http://mariadb.org Twitter - http://twitter.com/mariadb Google+ - http://google.com/+mariadb Facebook - http://fb.com/MariaDB.dbms Knowledgebase - http://kb.askmonty.org

3 4

[Maria-developers] RFC - query cache insert
by Roberto Spadim 16 Aug '13

16 Aug '13

Hi guys! I was reading (again) the query cache source code of 10.0.3 ... please tell me if i understood right when we insert at query cache... thread put a lock in query cache (no one can result from query cache) thread read all data and write to network (caching the result to query cache) after end of thread real the query cache is unlocked.. my doubts are... what happen if the query is too slow? the query cache is disabled while executing the query? what happen if two equal queries (same SELECT) execute? the first one is locked until the second one end the query and get the result from query cache? or the first lock query cache and the second runs without query cache? the last one there's any query cache changes in mind? i was reading the sql_cache.cc of old mysql servers and there's a todo list (very old i think) that didn't changed from old mysql to today mariadb 10.0.3, this todo list is inside mysql bug tracker? or mariadb jira? thanks guys! -- Roberto Spadim

2 11

[Maria-developers] doubt about workaround on MDEV-4903
by Roberto Spadim 16 Aug '13

16 Aug '13

hi guys, could anyone help me with a workaround to this MDEV? https://mariadb.atlassian.net/browse/MDEV-4903 basically the problem is a (more than one column primary key) IN ( (a primary key const value), (a primary key const value), (a primary key const value), (a primary key const value) ) it runs a table scan instead of using the primary key index using OR = OR = OR =, use the index but i want a easier way to write this query thanks -- Roberto Spadim

1 0

[Maria-developers] RFC - query cache using storage engine
by Roberto Spadim 15 Aug '13

15 Aug '13

Hi guys, i was thinking about ideas for query cache... there's an mdev about partitioning query cache ( https://mariadb.atlassian.net/browse/MDEV-4454) instead of this, why not use a HEAP storage engine (with partitioning), or maybe a myisam or aria or innodb as "backend", and write a "frontend" (query cache) that execute commands over this storage engine? i'm talking about, changing the query/table/result blocks of query cache, to query/table/result tables when start mysqld truncate these tables when add new query "insert" to these tables when a table prune occur, "delete" from these tables when flush, optimize these tables when reset query cache, truncate this tables these tables could be at mysql schema, if they don't exists create as ENGINE=MEMORY for example since we must have a MAX SIZE for query cache, we could add a MAX SIZE for HEAP engine and a LOW MEMORY algorithm ( https://mariadb.atlassian.net/browse/MDEV-4675) at high level, what you think about this idea? -- Roberto Spadim

2 3

Re: [Maria-developers] Fwd: [Commits] Rev 3674: MDEV-4645: Incorrect reads of frozen binlog events; FDE corrupted in relay log in file:///home/bell/maria/bzr/work-maria-10.0-base-MDEV-4645/
by Kristian Nielsen 15 Aug '13

15 Aug '13

Oleksandr Byelkin <sanja(a)montyprogram.com> writes: > Could you review this? > > (it is https://mariadb.atlassian.net/browse/MDEV-4645 ) Ok, but it will be at least a couple more days before I will have time to start. If urgent, you can also ask Sergei Golubchik, IIRC this is the patch from Jeremy Cole that he asked me about, and I already looked at once and accepted the general idea? - Kristian.

2 1

Re: [Maria-developers] Review of patch for MDEV-4820
by Kristian Nielsen 15 Aug '13

15 Aug '13

Vilho Raatikka <vilho.raatikka(a)skysql.com> writes: > Is this documented profoundly already? Should be because probably we'll see > at least some users as ignorant as I am asking the same questions soon. I wrote up some comprehensive documentation in the knowledgebase, and also wrote a series of articles about in on my blog: https://kb.askmonty.org/en/global-transaction-id/ http://kristiannielsen.livejournal.com/ But this is complex stuff, I am sure it can be improved. Any help improving the documentation would be greatly appreciated. I fear that I have spent too much time on the details of the design to clearly see how to explain the high-level picture in a way suitable for new users. - Kristian.

1 0