Explanation of my.ini or my.cnf configuration in MYSQL In MYSQL, the `my.ini` (commonly used on Windows systems) or `my.cnf` (commonly used on Linux/Unix systems) is the main configuration file for the MySQL server. This file contains various settings and parameters that control how the MySQL server operates. Below are some common sections and options found in these configuration files: 1. **[client]**: This section contains settings that apply to MySQL client programs. - `port`: Specifies the port number that clients use to connect to the MySQL server. - `socket`: Specifies the Unix socket file or Windows named pipe used for local connections. 2. **[mysqld]**: This section contains settings specific to the MySQL server daemon (`mysqld`). - `port`: Specifies the port number on which the server listens for TCP/IP connections. - `datadir`: Specifies the directory where data files are stored. - `socket`: Specifies the Unix socket file or Windows named pipe used for local connections. - `max_connections`: Specifies the maximum number of simultaneous client connections allowed. - `innodb_buffer_pool_size`: Specifies the size of the buffer pool used by InnoDB to cache data and indexes. - `query_cache_size`: Specifies the amount of memory allocated for caching query results. 3. **[mysql]**: This section contains settings specific to the `mysql` command-line client. - `no-auto-rehash`: Disables automatic rehashing, which can speed up startup time for the client. 4. **[mysqld_safe]**: This section contains settings for the `mysqld_safe` script, which is a wrapper around `mysqld` used to start the server safely. - `log-error`: Specifies the file to which error logs are written. - `pid-file`: Specifies the file where the server writes its process ID. These configuration files allow administrators to fine-tune the performance and behavior of the MySQL server according to their specific needs. Proper configuration can significantly improve the efficiency and reliability of the database system.

by swsw007 on 2008-12-05 22:11:53

All configurations mentioned in this article are excerpted from the *MySQL 5 Authority Guide (3rd Edition)*. Personally, I believe they are very useful for using MySQL. They are placed here for my own reference at any time, and I hope they will also be helpful to other friends. (Last updated on May 30, 2007)

**mysqld Program - Directories and Files:**

- **basedir = path**: Use the specified directory as the root directory (installation directory).

- **character-sets-dir = path**: Specify the directory where character sets are stored.

- **datadir = path**: Read database files from the specified directory.

- **pid-file = filename**: Specify a file for the mysqld program to store its process ID (only applicable to UNIX/Linux systems). The Init-V script needs to use the process ID in this file to terminate the mysqld process.

- **socket = filename**: Specify a socket file for local communication between MySQL client programs and the server (only applicable to UNIX/Linux systems; the default setting is generally the /var/lib/mysql/mysql.sock file).