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[Maria-developers] MariaDB 5.5.31 Release Prep
by Daniel Bartholomew 22 May '13

22 May '13

All, I've uploaded almost all of the packages for the release (working on a fix for an error with the sol-10 package) and the mirrors will be picking them up soon. Draft Changelog and Release Notes are here: - https://kb.askmonty.org/en/mariadb-5531-release-notes/ - https://kb.askmonty.org/en/mariadb-5531-changelog/ One of the big items in this release is TokuDB. We didn't have a proper category for TokuDB yet, so I created a stub TokuDB category with some links to the Tokutek website: - https://kb.askmonty.org/en/tokudb/ If there is anything I should be sure to mention in the release notes, please let me know ASAP. My current plan is to activate the release tomorrow, 23 May 2013. 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

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Re: [Maria-developers] [Commits] Rev 3769: MDEV-4520 fix
by Sergei Golubchik 22 May '13

22 May '13

Hi, Sanja! On May 22, sanja(a)montyprogram.com wrote: > ------------------------------------------------------------ > revno: 3769 > revision-id: sanja(a)montyprogram.com-20130522125526-aw778iepj1yceskd > parent: holyfoot(a)askmonty.org-20130514213637-3uvcda98gemgiquf > committer: sanja(a)montyprogram.com > branch nick: work-maria-5.5-MDEV-4520 > timestamp: Wed 2013-05-22 15:55:26 +0300 > message: > MDEV-4520 fix. First, please, fix the changeset comment. The first line should be MDEV-<number><space><complete issue summary> For example: MDEV-4520 Assertion `0' fails in Query_cache::end_of_result on concurrent drop event and event execution Then, after an empty line, you add whatever explanations you think are necessary. Like the one below: > If there is no net.vio then query cache cant't get data via > net_real_write() so it is better just do not try to cache such > query. Also, it'd be good to record the fixed bug in the changeset metadata. This can be done either with "bzr gcommit" and my patches to it (see the article in KB), or from the command line with "bzr commit --fixes". > === modified file 'sql/sql_cache.cc' > --- a/sql/sql_cache.cc 2013-05-07 11:05:09 +0000 > +++ b/sql/sql_cache.cc 2013-05-22 12:55:26 +0000 > @@ -3977,7 +3977,8 @@ Query_cache::is_cacheable(THD *thd, LEX > if (thd->lex->safe_to_cache_query && > (thd->variables.query_cache_type == 1 || > (thd->variables.query_cache_type == 2 && (lex->select_lex.options & > - OPTION_TO_QUERY_CACHE)))) > + OPTION_TO_QUERY_CACHE))) && > + thd->net.vio) > { > DBUG_PRINT("qcache", ("options: %lx %lx type: %u", > (long) OPTION_TO_QUERY_CACHE, The fix itself looks ok. But please add a test case. And think if there can be more cases (besides events) where SELECT is executed with thd->net.vio == 0. E.g. init-file? or init-connect? Or INSERT (in the replication thread) that invokes a stored function or a trigger? Anything you can think of. Regards, Sergei

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[Maria-developers] History of table changes
by Roberto Spadim 22 May '13

22 May '13

Hi guys, i was looking git and i don't know if there's something similar to mariadb alter table command could we develop something like git for create database,alter tables, create table, drop table, drop database? a log that could be useful to update databases table definition and read changes done and 'commits' done by dba or developer or a tool to read my table and read remote table and show the create command to make they in sync (ok here history is lost) thanks guys -- Roberto Spadim

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[Maria-developers] unexpected "Duplicate entry" error
by Kazuhiko Shiozaki 21 May '13

21 May '13

Hello, We sometimes (not always, not often but sometimes) have unexpected "Duplicate entry" error on the following table and with the following query : * table CREATE TABLE `category` ( `uid` bigint(20) unsigned NOT NULL, `category_uid` bigint(20) unsigned NOT NULL DEFAULT '0', `base_category_uid` bigint(20) unsigned NOT NULL DEFAULT '0', `category_strict_membership` tinyint(1) NOT NULL DEFAULT '0', PRIMARY KEY (`uid`,`category_uid`,`base_category_uid`,`category_strict_membership`), KEY `Membership` (`category_uid`,`base_category_uid`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci * query BEGIN; (some queries for other tables) DELETE FROM category WHERE uid=14026268; INSERT INTO category VALUES (14026268, 3131502, 2074, 1),(14026268, 2992, 2992, 0),(14026268, 3133077, 191, 1),(14026268, 1212264, 2992, 1); (some queries for other tables) COMMIT; * error Duplicate entry '14026268-3131502-2074-1' for key 'PRIMARY' But this duplicate entry error should not happen because DELETE is called in the same transaction, even if similar queries are sent from another connection at the same time. We confirmed that this kind of issue happens on the following environments using MySQL_python-1.2.3 : * MariaDB 5.5.25, XtraDB * MariaDB 5.5.29, XtraDB * MariaDB 5.5.29, InnoDB plugin Since it happens SOMETIMES, I cannot reproduce this issue by small query. Do you have any idea so that we can investigate this issue further ? Thanks in advance ! -- Kazuhiko Shiozaki Nexedi: Consulting and Development of Free / Open Source Software http://www.nexedi.com/ ERP5: Full Featured High End Open Source ERP http://www.erp5.com/

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Re: [Maria-developers] MariaDB and MySQL replication
by Kristian Nielsen 21 May '13

21 May '13

Jan Lindström <jplindst(a)mariadb.org> writes: > My question is how compatible replication between > > 1) MySQL (master) -> MariaDB (slave) > 2) MariaDB (master) -> MySQL (slave) In general, it should work, though there are some limitations. It also depends on versions. I always try to make MariaDB (master) -> MySQL (slave) work. For example, when new binlog events are introduced to MariaDB, the MariaDB master will not send them to slaves that do not understand the new events (whether MySQL slave, or older version of MariaDB), it will replace them with something compatible. This is not the best tested part of the code though, so there may be bugs. MySQL (master) -> MariaDB (slave) generally has limitations. This is the same as MySQL (high version master) -> MySQL (low version master). This is due to the MySQL replication teams approach, where you need to disable new features on the master for things to work with old slaves. For example, MySQL 5.6 (master) -> MySQL 5.5 (slave) does not work out-of-the box, so MariaDB 5.5 slave is the same. Generally, when incompatibilities are introduced in new MySQL versions used as a master, we will backport to MariaDB at least to the extent that new MariaDB versions will be able to replicate as slaves from a MySQL master without needing any special configuration. Though it depends on time available and priority against other work, for example there are known incompatibilities that have not yet been fixed in 10.0 alpha but will hopefully be fixed by 10.0 GA. Officially, replicating from new master to old slave is not supported (you should upgrade slaves first). This applies mostly the same whether MySQL or MariaDB or both are involved. Unofficially, as explained above, we do try to make it work as well as reasonably possible on the MariaDB side. > Before you say they are fully compatible, I point out at least > following types at mysql_com.h that do not exist on MariaDB mysql_com.h: > > MYSQL_TYPE_TIMESTAMP2, > MYSQL_TYPE_DATETIME2, > MYSQL_TYPE_TIME2, I do not know the details of this particular point (also you did not mention any version info). Best is probably to test it and see, and then report your findings and if needed we can file a bug for fixing things. - Kristian.

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Re: [Maria-developers] Getting community to write missing test cases
by Kristian Nielsen 21 May '13

21 May '13

Elena Stepanova <elenst(a)montyprogram.com> writes: > If we start doing it, Oracle will soon realize that this activity is > based at least as much on commit comments as on the code. As a result, > they will probably start making much vaguer comments than they do now, > which in turn might make merge and related activities even more > complicated than they are now. I wouldn't worry about that. First, I do not believe day-to-day developers spend any effort to actively conceal things for outside developers. The ban on bug test cases seems to have come from a generic security team mandate, which has roots some years back where Oracle were hit quite hard with countless vulnerabilities after their "can't break it - can't break in" campain. Second, even if they did, anything that makes Oracle close down more benefits the adoption of the forks. But most importantly, we must not get into the mentality that we let what Oracle might or might not do influence how we work. We need to go in whatever direction we believe is best for the project. Oracle has made it plain that they do not want to participate in the community, and we should just ignore them until such time as they might decide otherwise. - Kristian.

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[Maria-developers] Feature Request - Working auto_increment on BlackHole Engine
by Gordan Bobic 20 May '13

20 May '13

How difficult would be be to implement working auto-increment functionality on the BlackHole engine? This would be really useful for what I'm trying to do at the moment. Since it is not available and there are no sequences in MariaDB and MySQL, I have to resort to a hack such as a single-int-field table doing the auto-increment, and an insert trigger on the blackhole table to insert a null into the auto-increment tracking table, get LAST_INSERT_ID() to set the value in the auto-increment table, and then delete the record. Even with InnoDB log files and tablespace on tmpfs this makes the performance nosedive by a factor of 4 if the trigger doesn't bother cleaning up the auto-increment table, and a factor of 13 if it deletes the record immediately after inserting it. The actual times I tested with 24 inserter threads on a 24-thread server are 8m vs. 30m vs. 105m, i.e. a massive drop. Is there an better place than this list for a feature request? Gordan

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[Maria-developers] Ogg vorbis based table
by Roberto Spadim 18 May '13

18 May '13

Hi guys, i was listening some musics, and i had a idea... let's me explain Some systems are based in time and value, an example of scada systems. In this kind of system we have an 'channel' (like right or left sound channel) a timestamp and a value, normally a table like CREATE TABLE history( Channel int not null default 0, Datetimestamp decimal(22,7) not null default 0, Value decimal(22,5) default NULL, Primary key (channel,datetimestamp) ) Some explanations and features that scada systems use... Value can be NULL, in this case we could think like MUTE function on audio files Datetime normally are gmt, or unixtimestamp values with microsecond precision, they could be fixed interval or not, example... 1 2 3 4 5... (q second interval), in audio it's fixed sample rate, or not fixed interval (variable sample rate), like 1 3 4 9... Well what i'm thinking... today mariadb 10.0.2 started the CONNECT table type (please correct me if i'm wrong), that can 'connect' to a xml,txt,csv and others kinds of files to read and write it's values... Could we implement mp3, wave, ogg vorbis, file type type? This is a really nice 'table compression' for scada systems, and allow a new era of table type, think about... Select datetimestamp from someaudiofile where someniceaudiofunction()>1 In this example we could check date time where some scada value get over a fixed level, or where a frequency get higher and start a alarm condition, it could be used to get more information using statistics functions... i'm talking now about a new table type and new functions... but thats the idea... Anyone intested in this? About table compression think about compressing tax values in nasdaq for example, and execute a statistic analyse with this information... Well just some uses... Thanks for the space to show my idea and your time to read it Maybe a video table in future, or image based... just to use jpeg compreesion (x,y,color values) and others kinds of files... Bye

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[Maria-developers] Empty_queries vs Com_empty_queries
by Ian Gilfillan 18 May '13

18 May '13

I'm documenting the status variables at the moment, and have a question about Empty_queries vs Com_empty_queries. Com_empty_queries is not incremented when an empty result is returned, and appears to be incremented only when an empty query is sent to the server, eg: mysql --comments -e '-- sql comment' Empty_queries appears to match the empty queries returned with SHOW USER_STATISTICS. It increments each time a query is performed that returns an empty result. Currently the documentation on the user statistics page at https://kb.askmonty.org/en/user-statistics/ says that EMPTY_QUERIES (and therefore the Empty_queries status variable) is "The number of times this user's connections sent empty queries to the server", which would describe Com_empty_queries rather than Empty_queries, and would need to be corrected. The documentation on https://kb.askmonty.org/en/server-status-variables/ is what I've just written based on the above. Have I understood this correctly, or is there something else to it? thanks, ian

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[Maria-developers] To Sergei:
by Samarth Mathur 16 May '13

16 May '13

Hi Sergei.. just a few questions. Hope not to bother too much! does the .so file of two_questions exist in the mariadb 10.0.2 source code or was that just an example? Also, if I'm looking to implement pluggable authentication for LDAP, does the version of mariadb, i'm doing this on matter? if it does, which version would you recommend? I'm currently on v10.0.2.. What is the advantage of going for a pluggable authentication over say a module made for the PAM plugin in mariadb? Regards Sam

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