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MySQL 8.0 Reference Manual  /  ...  /  mysqldumpslow — Summarize Slow Query Log Files

6.6.10 mysqldumpslow — Summarize Slow Query Log Files

The MySQL slow query log contains information about queries that take a long time to execute (see Section 7.4.5, “The Slow Query Log”). mysqldumpslow parses MySQL slow query log files and summarizes their contents.

Normally, mysqldumpslow groups queries that are similar except for the particular values of number and string data values. It abstracts these values to N and 'S' when displaying summary output. To modify value abstracting behavior, use the -a and -n options.

Invoke mysqldumpslow like this:

mysqldumpslow [options] [log_file ...]

Example output with no options given:

Reading mysql slow query log from /usr/local/mysql/data/mysqld80-slow.log
Count: 1  Time=4.32s (4s)  Lock=0.00s (0s)  Rows=0.0 (0), root[root]@localhost
 insert into t2 select * from t1

Count: 3  Time=2.53s (7s)  Lock=0.00s (0s)  Rows=0.0 (0), root[root]@localhost
 insert into t2 select * from t1 limit N

Count: 3  Time=2.13s (6s)  Lock=0.00s (0s)  Rows=0.0 (0), root[root]@localhost
 insert into t1 select * from t1

mysqldumpslow supports the following options.

Table 6.24 mysqldumpslow Options

Option Name Description
-a Do not abstract all numbers to N and strings to 'S'
-n Abstract numbers with at least the specified digits
--debug Write debugging information
-g Only consider statements that match the pattern
--help Display help message and exit
-h Host name of the server in the log file name
-i Name of the server instance
-l Do not subtract lock time from total time
-r Reverse the sort order
-s How to sort output
-t Display only first num queries
--verbose Verbose mode

  • --help

    Command-Line Format --help

    Display a help message and exit.

  • -a

    Do not abstract all numbers to N and strings to 'S'.

  • --debug, -d

    Command-Line Format --debug

    Run in debug mode.

    This option is available only if MySQL was built using WITH_DEBUG. MySQL release binaries provided by Oracle are not built using this option.

  • -g pattern

    Type String

    Consider only queries that match the (grep-style) pattern.

  • -h host_name

    Type String
    Default Value *

    Host name of MySQL server for *-slow.log file name. The value can contain a wildcard. The default is * (match all).

  • -i name

    Type String

    Name of server instance (if using mysql.server startup script).

  • -l

    Do not subtract lock time from total time.

  • -n N

    Type Numeric

    Abstract numbers with at least N digits within names.

  • -r

    Reverse the sort order.

  • -s sort_type

    Type String
    Default Value at

    How to sort the output. The value of sort_type should be chosen from the following list:

    • t, at: Sort by query time or average query time

    • l, al: Sort by lock time or average lock time

    • r, ar: Sort by rows sent or average rows sent

    • c: Sort by count

    By default, mysqldumpslow sorts by average query time (equivalent to -s at).

  • -t N

    Type Numeric

    Display only the first N queries in the output.

  • --verbose, -v

    Command-Line Format --verbose

    Verbose mode. Print more information about what the program does.