ursitesion提出的问题 -dba

ursitesion

Asked: 2014-10-02 07:37:57 +0800 CST

Os threads no cache ainda usam memória?

1

Eu estava estudando sobre como e quanta memória alocada para cada thread de conexão e encontrei abaixo o tutorial do MySQL:

http://dev.mysql.com/doc/refman/5.1/en/memory-use.html

Há um ponto mencionado abaixo que não consigo entender.

Quando um thread não é mais necessário, a memória alocada para ele é liberada e retornada ao sistema, a menos que o thread volte para o cache de threads. Nesse caso, a memória permanece alocada.

Minhas preocupações são as seguintes:

Isso significa que o thread ocupou a memória mesmo que o sistema esteja usando threads do cache?
Um cache no thread ainda usa memória?

ursitesion

Asked: 2014-09-04 22:17:59 +0800 CST

MongoDB: como criar um novo banco de dados

2

Após a instalação, teste adminsão localo banco de dados padrão. Conforme o tutorial do MongoDB, quando inserimos dados na coleção, um banco de dados será listado no show dbscomando. Para uma finalidade específica, desejo criar um novo banco de dados, mas não encontrei nenhuma informação sobre como criar um novo banco de dados. Eu executei um comando como create db dbnameou create database dbname. Para ambas as declarações, recebi o erro abaixo: SyntaxError: Unexpected identifier

Posso saber quais são os passos para criar um banco de dados?

ursitesion

Asked: 2014-08-05 00:22:47 +0800 CST

MySQL: Qual junção é melhor entre a junção externa esquerda e a junção interna

14

Qual junção tem melhor desempenho se todas elas fornecerem o mesmo resultado? Por exemplo, eu tenho duas tabelas employees(emp_id,name, address, designation, age, sex)e work_log(emp_id,date,hours_wored). Para obter alguns resultados específicos tanto inner joine left joindá o mesmo resultado. Mas, ainda tenho algumas dúvidas que não se limitam apenas a esta questão.

qual junção é mais eficiente, qual deve preferir no caso de valores de resultados iguais?
Quais são os outros fatores que devem ser considerados no momento da aplicação da associação?
Existe alguma relação entre junção interna e junção cruzada?

ursitesion

Asked: 2014-07-23 04:12:32 +0800 CST

É possível desinstalar o MySQL-5.6 e instalar o MySQL-5.1 no RHEL 5

0

Instalei o MySQL-5.6.x community edition no RHEL5. Estava funcionando bem. Desde então, é meu servidor de teste. Para encontrar as diferenças no tempo de execução, tenho que instalar o MySQL-5.1 community edition novamente. Então, decidi desinstalar o MySQL-5.6 primeiro. Para fazer isso, segui os passos abaixo:

1. uninstall MySQL server and client
# sudo yum erase mysql
2. Uninstall mysql libraries
# sudo yum remove mysql-libs
3. clean db cache
# sudo yum clean dbcache
4. find each and every instance of MySQL
# sudo find / -name mysql*;
5. remove each and every instance of MySQL and Even libmysqlclient.so too.
# sudo rm -r /directory path
6. install shared library
 # sudo rpm -ivh /u000/mysql_installer/MySQL-shared-community-5.1.73-1.rhel5.x86_64.rpm
Result: successful 100%
6. install shared compat if you face any issue  
# sudo rpm -ivh /u000/mysql_installer/MySQL-shared-compat-5.1.73-1.rhel5.x86_64.rpm
Result: successful 100%
7. install mysql server
# sudo rpm -ivh /u000/mysql_installer/MySQL-server-community-5.1.73-1.rhel5.x86_64.rpm

Mas, estou recebendo muitos erros de conflito, como abaixo:

     file /etc/init.d/mysql from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
 file /etc/logrotate.d/mysql from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/innochecksum from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/my_print_defaults from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/myisam_ftdump from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/myisamchk from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/myisamlog from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/myisampack from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_convert_table_format from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_fix_extensions from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_install_db from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_secure_installation from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_setpermission from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_tzinfo_to_sql from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_upgrade from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysql_zap from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysqlbug from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysqld_multi from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysqld_safe from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysqldumpslow from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysqlhotcopy from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/mysqltest from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/perror from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/replace from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/resolve_stack_dump from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/bin/resolveip from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/sbin/mysqld from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/sbin/mysqld-debug from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/innochecksum.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/my_print_defaults.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/myisam_ftdump.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/myisamchk.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/myisamlog.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/myisampack.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql.server.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_convert_table_format.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_fix_extensions.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_install_db.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_secure_installation.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_setpermission.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_tzinfo_to_sql.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_upgrade.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysql_zap.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysqlbug.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysqld_multi.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysqld_safe.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysqldumpslow.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysqlhotcopy.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/mysqltest.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/perror.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/replace.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/resolve_stack_dump.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man1/resolveip.1.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/man/man8/mysqld.8.gz from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/SELinux/RHEL4/mysql.fc from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/SELinux/RHEL4/mysql.te from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/Index.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/armscii8.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/ascii.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/cp1250.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/cp1256.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/cp1257.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/cp850.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/cp852.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/cp866.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/dec8.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/geostd8.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/greek.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/hebrew.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/hp8.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/keybcs2.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/koi8r.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/koi8u.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/latin1.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/latin2.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/latin5.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/latin7.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/macce.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/macroman.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/charsets/swe7.xml from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/czech/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/danish/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/dutch/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/english/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/estonian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/fill_help_tables.sql from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/french/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/german/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/greek/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/hungarian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/italian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/japanese/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/korean/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/mysql-log-rotate from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/mysql.server from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/mysql_system_tables.sql from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/mysql_system_tables_data.sql from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/mysql_test_data_timezone.sql from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/norwegian-ny/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/norwegian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/polish/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/portuguese/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/romanian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/russian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/serbian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/slovak/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/spanish/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/swedish/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server-5.6.19-1.rhel5.x86_64
        file /usr/share/mysql/ukrainian/errmsg.sys from install of MySQL-server-community-5.1.73-1.rhel5.x86_64 conflicts with file from package MySQL-server

Finalmente o servidor MySQL não foi instalado. Não sei que erro cometi?

ursitesion

Asked: 2014-05-01 12:39:44 +0800 CST

O mecanismo InnoDB não está carregando após ajustar os parâmetros

2

Depois de instalar o MySQL-5.1.73, coloquei o padrão my-huge.cnf em /etc/my.cnf e iniciei o serviço mysql. Estava rodando sem nenhum problema. Agora, ajustei alguns parâmetros no arquivo /etc/my.cnf. Abaixo estão os parâmetros que alterei.

[mysqld]
key_buffer_size = 298M
max_allowed_packet = 1M
table_open_cache = 64
sort_buffer_size = 2M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 64M
thread_cache_size = 50
query_cache_size = 32M
query_cache_limit = 1M
# Try number of CPU's*2 for thread_concurrency
thread_concurrency = 2

e descomentei essas variáveis para o InnoDB. No arquivo padrão, foi comentado mesmo que o INNODB estivesse ativo.

# Uncomment the following if you are using InnoDB tables
innodb_data_home_dir = /var/lib/mysql
innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend
innodb_log_group_home_dir = /var/lib/mysql
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
innodb_buffer_pool_size = 1127M
innodb_additional_mem_pool_size = 20M
# Set .._log_file_size to 25 % of buffer pool size
innodb_log_file_size = 256M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50

Agora, para verificar se o InnoDB está disponível ou não, executei o show enginescomando. Mas o InnoDB não está listado nisso. Em seguida, executei o comando abaixo do comando:

mysql> show variables like '%innodb%';
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| have_innodb           | NO    |
| ignore_builtin_innodb | OFF   |
+-----------------------+-------+
2 rows in set (0.00 sec)

mysql> show engines;
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine     | Support | Comment                                                        | Transactions | XA   | Savepoints |
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
| MyISAM     | DEFAULT | Default engine as of MySQL 3.23 with great performance         | NO           | NO   | NO         |
| MRG_MYISAM | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| BLACKHOLE  | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| CSV        | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| MEMORY     | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| FEDERATED  | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
| ARCHIVE    | YES     | Archive storage engine                                         | NO           | NO   | NO         |
+------------+---------+----------------------------------------------------------------+--------------+------+------------+
7 rows in set (0.00 sec)

Eu não consigo encontrar onde eu fiz o erro? Você pode por favor ajudar?

Adicionando o caminho, o problema foi resolvido, mas não sei se o caminho está correto ou não!:

Verificar o log de erros certamente ajudou aqui. Com base no log de erros:

InnoDB: Error: data file /var/lib/mysql/ibdata1 is of a different size
InnoDB: 133760 pages (rounded down to MB)
InnoDB: than specified in the .cnf file 128000 pages!
InnoDB: Could not open or create data files.
Then, I commented - #innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend

Depois disso, recebi a mensagem de erro abaixo no arquivo de log de erros:

InnoDB: Error: log file /var/lib/mysql/ib_logfile0 is of different size 0 5242880 bytes
InnoDB: than specified in the .cnf file 0 268435456 bytes!
140430 17:13:37 [ERROR] Plugin 'InnoDB' init function returned error.
140430 17:13:37 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
Then, I commented #innodb_log_file_size = 256M By default #innodb_log_file_size = 5M.

Agora, iniciei novamente o serviço mysql e descobri que o Innodb foi carregado como mecanismo padrão.

ursitesion

Asked: 2014-04-28 07:48:36 +0800 CST

Existe algum comando para otimizar todas as tabelas do MySQL uma a uma automaticamente?

11

Eu executo a instrução de linha de comando abaixo para otimizar uma tabela: optimize table tablename;

Existe algum comando ou instrução que possa otimizar todas as tabelas uma a uma do banco de dados selecionado?

ursitesion

Asked: 2014-04-28 03:45:39 +0800 CST

Diferença entre [mysql] e [mysqld] no arquivo de configuração do MySQL

3

Existem várias seções no arquivo de configuração do MySQL:

[mysql]
[mysqld]
[myisamchk]
[mysqld_safe]
[mysqlhotcopy]
[mysqldump]
[cliente]

Descobri que as mesmas variáveis com valores diferentes foram definidas nessas seções.

Qual é o propósito específico por trás da definição dessas seções?
É necessário definir tudo?
Como o MySQL interpreta essas variáveis?

ursitesion

Asked: 2014-04-24 22:36:06 +0800 CST

O que isso significa - ~/.my.cnf

2

Quando corro $ mysqld --verbose --help | less, recebo informações como

Default options are read from the following files in the given order:
/etc/mysql/my.cnf /etc/my.cnf ~/.my.cnf

Pelo que entendi, na inicialização, o mysql primeiro procura my.cnf dentro /etc/mysql/my.cnf, depois dentro /etc/my.cnfe, finalmente, ~/.my.cnf.

Estou correcto?
Qual diretório isso significa - ~/.my.cnf?
Se uma variável x has value 100em /etc/mysql/my.cnfe novamente a mesma variável x has value 200em etc/my.cnf, qual valor realmente será aplicado?

ursitesion

Asked: 2014-04-24 09:43:56 +0800 CST

Existe alguma diferença entre essas duas versões do MySQL - 5.1.73-community-log Vs 5.1.73-community

3

Eu instalei o MySQL 5.1.73 no servidor Oracle LINUX 5 . Logo após a instalação do RPM, verifiquei as variáveis do sistema e descobri que a versão é 5.1.73-community. Quando copiei /usr/share/doc/MySQL-server-community-5.1.73/my-medium.cnf to /etc/my.cnf , obtive 5.1.73-community-log como valor da variável de versão. Estou curioso para saber qual é a diferença entre 5.1.73-community e 5.1.73-community-log

ursitesion

Asked: 2014-02-12 09:06:59 +0800 CST

Diferentes estados de thread na execução da consulta

1

Meu sistema de intranet baseado em MySQL 5.1 está enfrentando um desempenho muito ruim durante a carga alta. Quando observado através do MonYog, encontrei os estados de thread abaixo:

Estados de discussão

Podemos simplesmente entender os diferentes estados do thread por seu nome. Alguém pode fornecer o

diferenças entre esses estados?
Por que "enviar dados" está levando 76%?

ursitesion

Asked: 2013-12-14 03:32:38 +0800 CST

Por que usar WHERE 1 ou WHERE 1=1?

61

Normalmente, se as condições não forem exigidas em nossas instruções de consulta, não usamos uma WHEREcláusula. Mas eu vi uma WHERE 1cláusula sendo usada em muitos lugares, mesmo onde outras condições não estão presentes.

Por que isso é feito?
Existem benefícios específicos para o tempo de execução?
Permite outras funcionalidades?
O uso é WHERE 1=1semelhante a isso?

ursitesion

Asked: 2013-12-14 03:16:33 +0800 CST

MySQL: busca vários status globais e variáveis de sistema em uma única consulta

1

Quando executamos SHOW global status;ou SHOW variables;obtemos lista de 291 e 278 registros no resultset. Para a perspectiva de desempenho, apenas alguns deles são muito importantes. Eu tenho que buscar essas variáveis muitas vezes durante o desempenho. Por exemplo, podemos escrever abaixo várias declarações em uma?

show global status like 'Threads_cached';
show global status like 'Threads_connected';
show global status like 'Threads_created';
show global status like 'Threads_running';
show global status like 'Select_scan';

Se buscarmos essas variáveis em uma única declaração, será realmente uma grande ajuda...

ursitesion

Asked: 2013-12-04 03:46:26 +0800 CST

Diferença entre mostrar status e mostrar status global no mysql

5

Quando executo "mostrar status" e "mostrar status global" no MySQL em um intervalo de 5 segundos, recebo um conjunto de 291 resultados de cada vez. Mas, o valor de alguns parâmetros é diferente. Abaixo está a lista desses parâmetros:

Status Variable_name Valor Status global Variable_name Valor
Aborted_clients 2350 Aborted_clients 2347
Binlog_cache_use 1494076 Binlog_cache_use 1493386
Bytes_received 180 Bytes_received 14514902897
Bytes_sent 8124 Bytes_sent 73596494244
Com_admin_commands 0 Com_admin_commands 847561
Com_alter_table 0 Com_alter_table 478
Com_begin 0 Com_begin 1009
Com_change_db 1 Com_change_db 8127737
Com_commit 0 Com_commit 1004
Com_create_table 0 Com_create_table 235
Com_create_trigger 0 Com_create_trigger 25
Com_create_view 0 Com_create_view 4
Com_delete 0 Com_delete 417012
Com_delete_multi 0 Com_delete_multi 218
Com_drop_table 0 Com_drop_table 239
Com_drop_view 0 Com_drop_view 8
Com_insert 0 Com_insert 109750
Com_insert_select 0 Com_insert_select 14
Com_kill 0 Com_kill 104
Com_lock_tables 0 Com_lock_tables 233
Com_optimize 0 Com_optimize 1
Com_rollback 0 Com_rollback 4
Com_select 0 Com_select 4955791
Com_set_option 1 Com_set_option 9473284
Com_show_collations 0 Com_show_collations 3109
Com_show_create_table 0 Com_show_create_table 1181
Com_show_create_trigger 0 Com_show_create_trigger 25
Com_show_databases 0 Com_show_databases 5
Com_show_engine_status 0 Com_show_engine_status 9538
Com_show_fields 0 Com_show_fields 516
Com_show_function_status 0 Com_show_function_status 4
Com_show_grants 0 Com_show_grants 4
Com_show_keys 0 Com_show_keys 60
Com_show_open_tables 1 Com_show_open_tables 26714
Com_show_plugins 0 Com_show_plugins 2
Com_show_procedure_status 0 Com_show_procedure_status 4
Com_show_processlist 0 Com_show_processlist 27338
Com_show_status 2 Com_show_status 16508
Com_show_table_status 0 Com_show_table_status 940
Com_show_tables 0 Com_show_tables 7
Com_show_triggers 0 Com_show_triggers 235
Com_show_variables 0 Com_show_variables 3135
Com_stmt_close 0 Com_stmt_close 279
Com_stmt_execute 0 Com_stmt_execute 284
Com_stmt_prepare 0 Com_stmt_prepare 284
Com_unlock_tables 0 Com_unlock_tables 233
Com_update 0 Com_update 967361
Com_update_multi 0 Com_update_multi 2272
Conexões 8132537 Conexões 8129927
Created_tmp_disk_tables 0 Created_tmp_disk_tables 349226
Created_tmp_files 63684 Created_tmp_files 63645
Created_tmp_tables 1 Created_tmp_tables 3893159
Handler_commit 0 Handler_commit 7480404
Handler_delete 0 Handler_delete 75596
Handler_prepare 0 Handler_prepare 2151290
Handler_read_first 0 Handler_read_first 29815473
Handler_read_key 0 Handler_read_key 1217425496
Handler_read_next 0 Handler_read_next 3826008161
Handler_read_prev 0 Handler_read_prev 2418519
Handler_read_rnd 0 Handler_read_rnd 9075133
Handler_read_rnd_next 81 Handler_read_rnd_next 3683107601
Handler_rollback 0 Handler_rollback 21610
Handler_update 0 Handler_update 17784530
Handler_write 80 Handler_write 591666282
Innodb_buffer_pool_pages_dirty 58 Innodb_buffer_pool_pages_dirty 67
Innodb_buffer_pool_pages_flushed 1161267 Innodb_buffer_pool_pages_flushed 1160463
Innodb_buffer_pool_read_requests 2863173268 Innodb_buffer_pool_read_requests 2855722562
Innodb_buffer_pool_write_requests 47910334 Innodb_buffer_pool_write_requests 47904489
Innodb_data_fsyncs 284362 Innodb_data_fsyncs 284205
Innodb_data_writes 3562289 Innodb_data_writes 3560356
Innodb_data_write 3802343424 Innodb_data_write 3774550528
Innodb_dblwr_pages_write 1161267 Innodb_dblwr_pages_write 1160463
Innodb_dblwr_writes 38015 Innodb_dblwr_writes 37994
Innodb_log_write_requests 7780429 Innodb_log_write_requests 7778131
Innodb_log_writes 2336822 Innodb_log_writes 2335731
Innodb_os_log_fsyncs 208319 Innodb_os_log_fsyncs 208204
Innodb_os_log_write 98765824 Innodb_os_log_write 97323008
Innodb_pages_write 1161267 Innodb_pages_write 1160463
Innodb_row_lock_time 137380 Innodb_row_lock_time 137349
Innodb_row_lock_waits 5392 Innodb_row_lock_waits 5386
Innodb_rows_deleted 75654 Innodb_rows_deleted 75596
Innodb_rows_inserted 7773757 Innodb_rows_inserted 7773709
Innodb_rows_read 3816403633 Innodb_rows_read 3808082321
Innodb_rows_updated 916125 Innodb_rows_updated 915711
Key_blocks_unused 422872 Key_blocks_unused 422915
Key_read_requests 320523319 Key_read_requests 320497057
Key_reads 6024194 Key_reads 6024151
Key_write_requests 7668445 Key_write_requests 7668386
Last_query_cost 10.499 Last_query_cost 0
Tabelas_abertas 194 Tabelas_abertas 193
Opened_files 1628563 Opened_files 1628148
Opened_table_definitions 0 Opened_table_definitions 5639
Tabelas_abertas 0 Tabelas_abertas 490561
Qcache_free_blocks 58892 Qcache_free_blocks 60662
Qcache_free_memory 240024696 Qcache_free_memory 245087632
Qcache_hits 30351231 Qcache_hits 30338589
Qcache_inserts 3605606 Qcache_inserts 3602774
Qcache_not_cached 1339432 Qcache_not_cached 1338776
Qcache_queries_in_cache 77058 Qcache_queries_in_cache 75273
Qcache_total_blocks 213544 Qcache_total_blocks 211643
Consultas 62827552 Consultas 62802229
Dúvidas 5 Dúvidas 62659646
Select_full_join 0 Select_full_join 63072
Select_full_range_join 0 Select_full_range_join 31
Select_range 0 Select_range 378850
Select_scan 1 Select_scan 2750215
Slow_queries 0 Slow_queries 26778
Sort_merge_passes 0 Sort_merge_passes 33570
Sort_range 0 Sort_range 366065
Sort_rows 0 Sort_rows 8796695
Sort_scan 0 Sort_scan 449489
Table_locks_immediate 19683336 Table_locks_immediate 19666285
Threads_cached 196 Threads_cached 193
Threads_connected 7 Threads_connected 10
Tempo de atividade 205696 Tempo de atividade 205606
Uptime_since_flush_status 205696 Uptime_since_flush_status 205606

Como ambas as consultas são iguais, por que tantos parâmetros têm valores diferentes? Observe que estou usando o MySQL 5.1 community edition. Eu tenho apenas um banco de dados ativo neste servidor de banco de dados Windows 2008 dedicado. Por favor, deixe-me saber se você precisar de qualquer outra informação.

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