mysql

This post explains why the mysql.sys@localhost user exists and what it is used for. The mysql.sys@localhost user is a system user used as the definer for view, procedures, and functions in the sys schema. It was added in MySQL 5.7.9 to avoid issues if the DBA renames the root@localhost user. See also MySQL sys Schema in the Reference Manual. The following applies to the mysql.sys@localhost user: 1. It is a required user as long as the sys schema is installed. Please do not drop the … [Read more...] about What is the purpose of “mysql.sys@localhost” user

The primary function of the MySQL authorization system is to associate an authenticated user with privileges on a database, such as SELECT, INSERT, UPDATE, and DELETE. The authorization system’s functionality includes the ability to have anonymous users and to enable specific functions such as LOAD DATA INFILE and various administrative operations. This authorization ensures that users can perform only the operations for which they have been granted appropriate privileges. Determining … [Read more...] about Understanding MySQL Privileges

MySQL supports a number of authentication mechanisms that are available through pluggable authentication. MySQL uses a number of algorithms to encrypt passwords stored in the user table: The mysql_native_password plugin implements the standard password format, a 41-byte-wide hash. The mysql_old_password plugin implements an older format that is less secure, being 16 bytes wide. The sha256_password plugin implements the SHA-256 hashing algorithm widely used in secure computing. The … [Read more...] about Understanding MySQL Pluggable Authentication

Managing users in MySQL gives you the ability to control what users can and cannot do. Create user accounts with different privileges that are appropriate to their function. Avoid using the root account - Constrain compromised applications and protect against mistakes during routine maintenance. Ensure data integrity by proper assignment of individual user privileges. Permit authorized users to do their work. Prevent unauthorized users from accessing data beyond their privileges. User … [Read more...] about Beginners Guide to MySQL User Management

OS error 11 is "Resource temporarily unavailable". The most common cause of receiving this error when trying to create a new thread is having hit the process's kernel enforced a limit on open file descriptors. The second most common cause is having hit the process's kernel enforced limit on the number of processes/threads. Here are the factors involved: The system-wide limits: sysctl -e fs.file-max && sysctl -e kernel.threads-max The per-process limits (in a *new* shell): ulimit -n, grep … [Read more...] about MySQL Server Error – “Can’t Create A New Thread (errno 11)”