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https://dev.mysql.com/doc/refman/8.4/en/mysqld.html
MySQL Server manages access to the MySQL data directory that contains databases and tables. mysqld, also known as MySQL Server, is a single multithreaded program that does most of the work in a MySQL installation. The data directory is also the ...
https://dev.mysql.com/doc/refman/8.4/en/mysqldumpslow.html
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 ...
https://dev.mysql.com/doc/refman/8.4/en/non-typed-operators.html
->> Return value from JSON column after evaluating path and unquoting the result; equivalent to JSON_UNQUOTE(JSON_EXTRACT()). / Division operator := Assign a value = Assign a value (as part of a SET statement, or as part of the SET clause in an ...
https://dev.mysql.com/doc/refman/8.4/en/numeric-functions.html
Table 14.8 Numeric Functions and Operators Name Description %, MOD Modulo operator * Multiplication operator + Addition operator - Minus operator - Change the sign of the argument / Division operator ABS() Return the absolute value ACOS() Return ...
https://dev.mysql.com/doc/refman/8.4/en/numeric-types.html
The BIT data type stores bit values and is supported for MyISAM, MEMORY, InnoDB, and NDB tables. These types include the exact numeric data types (INTEGER, SMALLINT, DECIMAL, and NUMERIC), as well as the approximate numeric data types (FLOAT, REAL, ...
https://dev.mysql.com/doc/refman/8.4/en/optimization-indexes.html
The index entries act like pointers to the table rows, allowing the query to quickly determine which rows match a condition in the WHERE clause, and retrieve the other column values for those rows. The best way to improve the performance of SELECT ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-features-to-trace.html
They are: Greedy search: With an N-table join, this could explore factorial(N) plans. Some features in the optimizer can be invoked many times during statement optimization and execution, and thus can make the trace grow beyond reason. Range ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-tracing-typical-usage.html
To perform optimizer tracing entails the following steps: Enable tracing by executing SET optimizer_trace="enabled=ON". See Section 10.15.3, “Traceable Statements”, for a listing of statements which can be traced. To examine traces for multiple ...
https://dev.mysql.com/doc/refman/8.4/en/optimizer-tracing.html
The MySQL optimizer includes the capability to perform tracing; the interface is provided by a set of optimizer_trace_xxx system variables and the INFORMATION_SCHEMA.OPTIMIZER_TRACE table.
https://dev.mysql.com/doc/refman/8.4/en/optimizing-database-structure.html
In your role as a database designer, look for the most efficient way to organize your schemas, tables, and columns. As when tuning application code, you minimize I/O, keep related items together, and plan ahead so that performance stays high as the ...