https://dev.mysql.com/custom-benchmarks.html
Most of the time, these problems would be much easier to fix if the systems were not already in production. Benchmark your application and database to find out where the bottlenecks are. After fixing one bottleneck (or by replacing it with a ...
https://dev.mysql.com/data-dictionary-object-cache.html
The stored_program_cache option sets a soft upper limit for the number of cached stored procedures or functions per connection, and the limit is checked each time a connection executes a stored procedure or function. The dictionary object cache is ...
https://dev.mysql.com/data-dictionary-schema.html
Generally, the difference between MySQL data dictionary tables and system tables is that data dictionary tables contain metadata required to execute SQL queries, whereas system tables contain auxiliary data such as time zone and help information.
https://dev.mysql.com/data-lock-waits-table.html
Use the data_lock_waits table to help diagnose performance problems that occur during times of heavy concurrent load. The data_lock_waits table implements a many-to-many relationship showing which data lock requests in the data_locks table are ...
https://dev.mysql.com/date-calculations.html
To determine how many years old each of your pets is, use the TIMESTAMPDIFF() function. DATE_ADD() enables you to add a time interval to a given date. MySQL provides several functions that you can use to perform calculations on dates, for example, ...
https://dev.mysql.com/dbug-package.html
Here are some example debug control strings as they might be specified on a shell command line: --debug=d:t --debug=d:f,main,subr1:F:L:t,20 --debug=d,input,output,files:n --debug=d:t:i:O,\\mysqld.trace For mysqld, it is also possible to change DBUG ... The MySQL server and most MySQL clients are compiled with the DBUG package originally created by Fred ...
https://dev.mysql.com/ddl-rewriter-options.html
If values specified at startup time are incorrect, the ddl_rewriter plugin may fail to initialize properly and the server does not load it. This section describes the command options that control operation of the ddl_rewriter plugin. To control ...
https://dev.mysql.com/debugging-server.html
If mysqld starts to eat up CPU or memory or if it “hangs,” you can use mysqladmin processlist status to find out if someone is executing a query that takes a long time. If you are using some functionality that is very new in MySQL, you can try ...
https://dev.mysql.com/delete-optimization.html
The time required to delete individual rows in a MyISAM table is exactly proportional to the number of indexes. To delete rows more quickly, you can increase the size of the key cache by increasing the key_buffer_size system variable. To delete all ...
https://dev.mysql.com/derived-tables.html
For information about lateral derived tables preceded by the LATERAL keyword, see Section 13.2.11.9, “Lateral Derived Tables”. A derived table is an expression that generates a table within the scope of a query FROM clause. For example, a ...
