- discuss - lists.mariadb.org

[Maria-discuss] new mdev about better explain
by Roberto Spadim 02 Dec '14

02 Dec '14

Hi guys, any help is wellcome here the problem: why optimizer chose a "bad" index? an example about this problem is MDEV-7125 i have this EXPLAIN output: id|select_type|table|type|possible_keys|key|key_len|ref|rows|Extra 1|SIMPLE|c|const|PRIMARY,NewIndex|PRIMARY|265|const,const|1|Distinct; Using temporary 1|SIMPLE|b|range|PRIMARY,id,plano_conta_numero,cod_busca|cod_busca|265|(NULL)|49|Using index condition; Distinct *1|SIMPLE|a|ref|cfop,item,transferencias,rendimento,estoque,giro|item|6|const,19_org.b.plano_conta_id_red|3347|Using where; Distinct* 1|SIMPLE|d|eq_ref|PRIMARY,NewIndex|PRIMARY|265|19_org.a.estoque_entrada_org,const|1|Using index condition; Using where; Distinct --- check the row from table "a" 1|SIMPLE|a|ref|*cfop,item,transferencias,rendimento,estoque,giro*|item|6|const,19_org.b.plano_conta_id_red|3347|Using where; Distinct optimizer found 5 possible index, and chose the "item" index, instead of "rendimento" index, it's not the best index, but i don't know why optimizer prefer "item" instead of "rendimento" to "solve" (explain) this optimizer choise i execute force index in each index and get output from explain... example EXPLAIN SELECT ... FROM est_mov AS a FORCE INDEX (cfop) ... EXPLAIN SELECT ... FROM est_mov AS a FORCE INDEX (item) ... EXPLAIN SELECT ... FROM est_mov AS a FORCE INDEX (transferencias) ... EXPLAIN SELECT ... FROM est_mov AS a FORCE INDEX (rendimento) ... EXPLAIN SELECT ... FROM est_mov AS a FORCE INDEX (estoque) ... EXPLAIN SELECT ... FROM est_mov AS a FORCE INDEX (giro) ... and compare each output to know why it chose the index 'item' as 'best' option could be possible a better explain from optimizer? something like { 'item': {'key_len':1234, 'ref rows':'blablalba', 'filtered' 99, 'extra':'blabla'}, 'transferencias': {'key_len':1234, 'ref rows':'blablalba', 'filtered' 99, 'extra':'blabla'}, 'rendimento': {'key_len':1234, 'ref rows':'blablalba', 'filtered' 99, 'extra':'blabla'}, 'giro': {'key_len':1234, 'ref rows':'blablalba', 'filtered' 99, 'extra':'blabla'} } i don't know if optimizer have this information, but it's relevant? could we implement a better explain? what others users (dba/developer) do when they have this problem (optimizer selecting the wrong index)? thanks guys -- Roberto Spadim SPAEmpresarial Eng. Automação e Controle

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[Maria-discuss] New Question: Upgrade vom v5.5 to 10 using OpenSuse 13.1 (64bit) and Intel (no AMD)
by AskMonty KB 29 Nov '14

29 Nov '14

Hello, A new question has been asked in "MariaDB community" by thomasschulze. Please answer it at http://mariadb.com/kb/en/upgrade-vom-v55-to-10-using-opensuse-131-64bit-and… as the person asking the question may not be subscribed to the mailing list. -------------------------------- Hi, regarding the upgrade to to v10.0, I found at: http://yum.mariadb.org/10.0/ and https://downloads.mariadb.org/mariadb/repositories/#mirror=23Media&version=… that Intel processors are not support yet, is that true. I assume that installing it from source wouldn't work out as well? How are we able to upgrade to v10, using OpenSuSe 13.1 (64bit); Intel? Does anybody got an idea here? Thanks! -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/upgrade-vom-v55-to-10-using-opensuse-131-64bit-and…

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[Maria-discuss] New Question: Waiting for table metadata lock - during parallel database loads
by AskMonty KB 25 Nov '14

25 Nov '14

Hello, A new question has been asked in "MariaDB community" by stephenwerner. Please answer it at http://mariadb.com/kb/en/waiting-for-table-metadata-lock-during-parallel-da… as the person asking the question may not be subscribed to the mailing list. -------------------------------- Hi, Is there a parameter/system variable that can be set to allow multiple database loads? It seems to be a right handbrake when loading more than one database at a time. Regards, Stephen. -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/waiting-for-table-metadata-lock-during-parallel-da…

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[Maria-discuss] MariaDB 10.1 uses huge amount of memory onWndows
by Peter Laursen 23 Nov '14

23 Nov '14

Please see attached imaged - a screenshot of Windows Task manager. I have a lot of MySQL and MariaDB servers installed (all needed for application testing). It is noticeable that MariaDB 10.1 uses around twice as much as much memory as compared to MariaDB 10.0, MySQL 5.6 and 5.7 (5 GB versus 2.5 GB in rough numbers). Even more surprising to me as P_S is not running with 10.1 (as I understand). Further I have MariaDB 10.0 running virtualized in OpenSuSE 12.3 inside Virtualbox. The process for the virtual machine use only around 10% or memory as compared to MariaDB 10.0 running natively on Windows (there is also an active VM running Mint Linux - but MySQL is not running there currently) I also have a number of older MySQL servers (5.0, 5.1 and 5.5) The use much less memory. That is expected as the configuration reserves smaller buffers. Both MariaDB servers in Windows use the configuration created by the installer. MySQL 5.6 adn 57 servers use the MySQL Installer standard "developer machine" configuration. The configuraiton of MariaDB 10 in SuSE is as shipped with the distro (I did not check it actually). None of the servers have been connected to since system was restarted. System has been running for approximately 4 hours and all servers start with Windows. The VM with SuSE has been running for approxmately 2 hours. In the attached image I have framed and starred my observations. I want to emphatize, that I don't face any problems with this at all. I have 32 GB RAM and 4 CPUs each capable of processing 2 parallel threads,and I can run Windows 7 with all the servers you see (and simultaneously use the system iinteractively for Internet browsing, playing media, processing photos, document creation/editing and what else you would do with a desktop system), as well as have the two VMs (both configured with an upper resource limit of 24 GB RAM and 6 CPU threads). The memory may be released if it is required by other processes. I don't think it is a problem to use memory if it is available if it will be released when it is required elsewhere (on the opposite it was a little expensive, so it would be a shame if it was not used at all!) But still I find the find the MariaDB 10.1 number for memory use so much *off* as compared to comparable servers, that I think I should mention the observation here. IMO it should be understood **why** it happens and next it can be decided **if** a fix is necessary or not. -- Peter -- Webyog

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[Maria-discuss] (no subject)
by Pierre GOUPIL 22 Nov '14

22 Nov '14

Good morning, Is there a way to have MariaDB run in-memory? I mean, without changing the table engines. I have my production code which needs to be persisted to disk, but for my unit tests, it would be great to have an in-memory DB. I'm in the Java world and I've tried HSQLDB but its SQL implementation is way too different than that of MariaDB. Any ideas? Cheers, Zala -- NoT DeaD which can eternal live, Stranger eons death may die. (HP Lovecraft)

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[Maria-discuss] New Question: link to debugging
by AskMonty KB 21 Nov '14

21 Nov '14

Hello, A new question has been asked in "Compiling MariaDB From Source" by daniel-black. Please answer it at http://mariadb.com/kb/en/link-to-debugging/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- can a link to [[Compiling MariaDB for debugging]] be added to this page? -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/link-to-debugging/

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[Maria-discuss] New Question: how to compile tokudb engine in MariaDB 10.0.14
by AskMonty KB 20 Nov '14

20 Nov '14

Hello, A new question has been asked in "SQL Language Structure" by wenfangzhang. Please answer it at http://mariadb.com/kb/en/how-to-compile-tokudb-engine-in- mariadb-10014/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- I want to ues tokudb engine for testing in MariaDB 10.0.14, but i don't know how to compile if from source code? -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/how-to-compile-tokudb-engine-in-mariadb-10014/

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[Maria-discuss] Can't delete row in table Mariadb-galera
by Carlos R Laguna 19 Nov '14

19 Nov '14

Hello everyone i am try to delete some row from a specific table in my DB however this never take place, i though it was because galera-limitations but my table has a primary key +---------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +---------------+--------------+------+-----+---------+-------+ | id | varchar(255) | NO | PRI | NULL | | | actions | varchar(255) | NO | | NULL | | | clientip | char(15) | NO | | NULL | | | date | date | NO | MUL | NULL | | | from_address| varchar(255) | NO | MUL | NULL | | | from_domain varchar(255) | NO | MUL | NULL | | | headers | longtext | NO | | NULL | | | hostname | longtext | NO | | NULL | | | highspam | int(11) | NO | MUL | 0 | | | rblspam | int(11) | NO | | 0 | | | saspam | int(11) | NO | | 0 | | | spam | int(11) | NO | MUL | 0 | | | nameinfected| int(11) | NO | | 0 | | | otherinfected | int(11) | NO | | 0 | | | isquarantined | int(11) | NO | MUL | 0 | | | sascore | double | NO | | NULL | | | scaned | int(11) | NO | | 0 | | | size | int(11) | NO | | NULL | | | blacklisted | int(11) | NO | MUL | 0 | | | spamreport | longtext | NO | | NULL | | | whitelisted | int(11) | NO | MUL | 0 | | | subject | longtext | NO | | NULL | | | time | time | NO | | NULL | | | timestamp | datetime | NO | MUL | NULL | | | to_address | varchar(255) | NO | MUL | NULL | | | to_domain | varchar(255) | NO | MUL | NULL | | | virusinfected | int(11) | NO | | 0 | | +---------------+--------------+------+-----+---------+-------+ this is the script i am running against the db class Command(NoArgsCommand): "Archive messages and delete from messages table" help = _("Deletes records older than QUARANTINE_DAYS_TO_KEEP" " days from the messages table") def handle_noargs(self, **options): #import datetime #from baruwa.messages.models import Message #interval = datetime.timedelta(days=60) #last_date = datetime.datetime.now() - interval #Message.objects.filter(timestamp__lt=last_date).delete() days = getattr(settings, 'QUARANTINE_DAYS_TO_KEEP', 10) conn = connection.cursor() conn.execute( """DELETE FROM messages WHERE id in (SELECT id FROM archive WHERE timestamp < DATE_SUB(CURDATE(), INTERVAL %s DAY)) """ % str(days) ) conn.execute( """INSERT LOW_PRIORITY INTO archive SELECT * FROM messages WHERE timestamp < DATE_SUB(CURDATE(), INTERVAL %s DAY) """ % str(days) ) conn.execute( """DELETE LOW_PRIORITY FROM messages WHERE timestamp < DATE_SUB(CURDATE(), INTERVAL %s DAY) """ % str(days) ) conn.execute('OPTIMIZE TABLE messages') conn.execute('OPTIMIZE TABLE archive') Is this a limitation? or i am facing something else. Thanks in advance for your time. Regards ________________________________________________________________ XII Edicion del Evento Nacional de Informatica para Jovenes. INFOCLUB. Abril. 2015. Ver www.jovenclub.cu ________________________________________________________________ -- Este mensaje ha sido analizado por MailScanner en busca de virus y otros contenidos peligrosos, y se considera que est� limpio.

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[Maria-discuss] New Question: MariaDB sorting issue
by AskMonty KB 17 Nov '14

17 Nov '14

Hello, A new question has been asked in "MariaDB FAQ" by sagarlotiya. Please answer it at http://mariadb.com/kb/en/mariadb-sorting-issue/ as the person asking the question may not be subscribed to the mailing list. -------------------------------- Hi, I have one table with 4 million rows and other table with 1 million rows. When I perform join on both the table and perform the sort on the column which is not main table it is behaving really slow. I have tested with 8 GB RAM. Whole database fits in memory. I have also checked with EXPLAIN it is not creating temporary table on disk. How can I get best performance? e.g query. SELECT DISTINCT u0_.id AS id_0, a1_.created_at AS created_at_1 FROM user u0_ LEFT JOIN advertise a1_ ON (a1_.user_id = u0_.id) ORDER BY a1_.created_at DESC LIMIT 10; Also note that all the indexes are properly created so that is not he issue here. -------------------------------- To view or answer this question please visit: http://mariadb.com/kb/en/mariadb-sorting-issue/

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[Maria-discuss] pid file could not be found
by Roth, Sandro 14 Nov '14

14 Nov '14

Hi there I'm having a weird problem after a fresh installation of RHEL6 and MariaDB: [root@server ~]# yum install MariaDB-10.1.1-centos6-x86_64-server.rpm MariaDB-10.1.1-centos6-x86_64-client.rpm MariaDB-10.1.1-centos6-x86_64-compat.rpm MariaDB-10.1.1-centos6-x86_64-common.rpm [...] [root@server ~]# /etc/init.d/mysql status MySQL is not running [FAILED] [root@server ~]# /etc/init.d/mysql start Starting MySQL. [ OK ] [root@server ~]# /etc/init.d/mysql status MySQL is running but PID file could not be found [FAILED] [root@spch9140 ~]# ls -al /var/lib/mysql/server.local-recover.pid -rw-rw---- 1 mysql mysql 6 Nov 14 07:41 /var/lib/mysql/server.local-recover.pid [root@server ~]# more /var/lib/mysql/server.local-recover.pid 25071 [root@server ~]# ps aux | grep 25071 mysql 25071 0.0 2.9 795548 116980 pts/0 Sl 07:41 0:02 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/server.local.err --pid-file=/var/lib/mysql/server.local.pid --wsrep_recover --log_error=/var/lib/mysql/wsrep_recovery.U7vwNv --pid-file=/var/lib/mysql/server.local-recover.pid root 27665 0.0 0.0 103256 856 pts/0 S+ 08:30 0:00 grep 25071 Also tried version 10.0.14, same issue.. Putting 'pid-file' option into /etc/my.cnf.d/server.cnf doesn't help either :( Anyone seen this too or have a suggestion? Thanks Sandro This email message and any attachments are confidential and may be privileged. If you are not the intended recipient, please notify us immediately and destroy the original transmittal. You are hereby notified that any review, copying or distribution of it is strictly prohibited. Thank you for your cooperation. Header information contained in E-mails to and from the company are monitored for operational reasons in accordance with swiss data protection act.

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