You can use the following query to get all duplicated records of a MySQL table having equal values for the respective field: SELECT fieldname, COUNT(*) FROM tablename GROUP BY fieldname HAVING COUNT(*) > 1 This query will give you a list of all the entries having the same value for fieldname. It also will show […]
To get information about the currently connected user and more MySQL status information, you can call the following command if you are already logged in: This will give you an output like that: ————– mysql Ver 14.14 Distrib 5.1.73, for redhat-linux-gnu (x86_64) using readline 5.1 Connection id: 1044395 Current database: Current user: niceguy@localhost SSL: Not in […]
You can see all running queries in live time with: $> mysqladmin -u dbuser -p123 -i 2 processlist The option -i determines the number of seconds between refreshes(alias –sleep=DELAY).
To check and optimize tables of a MySQL database: $> mysqlcheck -os <db_name> -u<username> -p To achieve the same for all databases of the respective MySQL server you can run the following command: $> mysqlcheck -Aos -u<username> -p Further information about check and optimize tables in MySQL To get a few more facts about how […]
To find out where the MySQL configuration (my.cnf) is stored, you can use the strace command: $> strace mysql “;” 2>&1 | grep my.cnf You will get an output showing all the paths the MySQL deamon searches for the my.cnf upon startup like that: stat(“/etc/my.cnf”, 0x7fffecb75210) = -1 ENOENT (No such file or directory) stat(“/etc/mysql/my.cnf”, {st_mode=S_IFREG|0644, st_size=3505, […]
mytop is an mysql tool written in Perl to look at the database queries during runtime. This is how to debug queries with mytop. Installation apt-get install mytop Usage mytop -u USERNAME -pPASSWORD -d DATABASE
