DE

↑ ↓ select, Enter open, Esc close

Analyze the slow query log for the slowest queries

harmless rootMySQL and MariaDBdebian, ubuntu
Adjust the values, the command updates live
root@server
mysqldumpslow -s t -t 10 /var/log/mysql/mariadb-slow.log

Groups queries that differ only in their concrete values and sorts them by total runtime (-s t). It shows the ten most expensive patterns with count, average time and a sample query. This allows targeted optimization instead of chasing individual outliers.

Note: -s c sorts by frequency. SHOW VARIABLES LIKE 'slow_query_log_file'; shows the current log path.

Open question before approval: Prüfen, ob mysqldumpslow bzw. mariadb-dumpslow auf Debian 12 mit MariaDB 10.11 im Paket mariadb-server enthalten ist und welcher Logpfad tatsächlich gesetzt ist.

Also searched as

  • analyze mysql slow query log
  • which queries are the slowest
  • mysql performance analysis

Related one-liners

All in MySQL and MariaDB

Enable the slow query log at runtime

#mysql -e 'SET GLOBAL slow_query_log = 1; SET GLOBAL long_query_time = 2; SHOW VARIABLES LIKE "slow_query_log_file";'
cautionMySQL and MariaDB

Back up a single database consistently as gzip

$mysqldump --single-transaction --quick -u dbuser -p wp_example | gzip > /var/www/vhosts/example.com/wp_example.sql.gz
harmlessMySQL and MariaDB

Back up all databases into one gzipped file

#mysqldump --single-transaction --quick --all-databases --routines --events | gzip > /root/all-databases.sql.gz
harmlessMySQL and MariaDB

Back up each database into its own gzipped file

#for db in $(mysql -NBe 'SHOW DATABASES' | grep -Ev '^(information_schema|performance_schema|sys)$'); do mysqldump --single-transaction --quick "$db" | gzip > "/root/db-backup/$db.sql.gz"; done
harmlessMySQL and MariaDB

Check all MySQL tables for errors

#mysqlcheck --all-databases --check --silent
harmlessMySQL and MariaDB

Compare max connections with the peak so far

#mysql -e "SHOW GLOBAL STATUS LIKE 'Max_used_connections'; SHOW GLOBAL VARIABLES LIKE 'max_connections';"
harmlessMySQL and MariaDB

Read first, then run.

The commands on myline.de act directly on servers, files and databases. A wrong path or placeholder can delete data irreversibly or make a server unreachable.

  • All commands are provided without warranty and are not tested on every system.
  • Understand what a command does before running it, and check every placeholder.
  • Make a backup first and, if possible, try it on a test system.
  • You run commands at your own risk. Liability for damages is excluded to the extent permitted by law.