https://dev.mysql.com/no-login-pluggable-authentication.html
With this plugin-loading method, the option must be given each time the server starts. If you installed the plugin at runtime using an INSTALL PLUGIN statement, it remains installed across server restarts. The mysql_no_login server-side ...
https://dev.mysql.com/no-matching-rows.html
Remove one table at a time from the query until it returns some rows. If you have a complicated query that uses many tables but that returns no rows, you should use the following procedure to find out what is wrong: Test the query with EXPLAIN to ...
https://dev.mysql.com/not-enough-file-handles.html
To tell mysqld to keep open fewer files at a time, you can make the table cache smaller by reducing the value of the table_open_cache system variable (the default value is 64). If you get ERROR 'file_name' not found (errno: 23), Can't open file: ...
https://dev.mysql.com/optimization-indexes.html
Although it can be tempting to create an indexes for every possible column used in a query, unnecessary indexes waste space and waste time for MySQL to determine which indexes to use. The best way to improve the performance of SELECT operations is ...
https://dev.mysql.com/optimization.html
Sometimes you can be proactive and plan in advance for performance, while other times you might troubleshoot a configuration or code issue after a problem occurs. This chapter explains how to optimize MySQL performance and provides examples.
https://dev.mysql.com/optimize-benchmarking.html
To measure performance, consider the following factors: Whether you are measuring the speed of a single operation on a quiet system, or how a set of operations (a “workload”) works over a period of time. For benchmarking, sometimes you must ...
https://dev.mysql.com/optimize-character.html
When you use a randomly generated value as a primary key in an InnoDB table, prefix it with an ascending value such as the current date and time if possible. For character and string columns, follow these guidelines: Use binary collation order for ...
https://dev.mysql.com/optimizing-innodb-diskio.html
(Measure at a time when the server is not doing bulk inserts; it is normal during bulk inserts for the modified pages percentage to rise significantly.) Log sequence number - Last checkpoint is at less than 7/8 or ideally less than 6/8 of the total ... If you follow best practices for database design and tuning techniques for SQL operations, but your database is still slow due to heavy disk I/O activity, consider these disk I/O ...
https://dev.mysql.com/optimizing-innodb-queries.html
Follow these guidelines for InnoDB indexes: Because each InnoDB table has a primary key (whether you request one or not), specify a set of primary key columns for each table, columns that are used in the most important and time-critical queries. To ...
https://dev.mysql.com/optimizing-innodb-storage-layout.html
You may find that there are significant gains for some and not for others, or that the gains decrease over time until you next optimize the table. Once your data reaches a stable size, or a growing table has increased by tens or some hundreds of ...
