啟用 MySQL 交易支援：InnoDB 安裝配置與驗證完整流程 (Linux)

前置條件

• 下載 Max 版本 (含 InnoDB)，如 mysql-max-3.23.47-pc-linux-gnu-i686.tar.gz
• 非 RPM 安裝，採用二進位包解壓至 /usr/local

安裝關鍵步驟

1. 建立 mysql 用戶/群組
2. scripts/mysql_install_db 初始化資料目錄
3. 權限設定：chown -R mysql /usr/local/mysql/data
4. 編寫啟動腳本 startMysqld，加入 rc.local 開機自啟

啟用 InnoDB：my.cnf 關鍵參數

[mysqld]
innodb_data_home_dir = /usr/local/mysql/var/
innodb_data_file_path = ibdata1:100M
innodb_log_group_home_dir = /usr/local/mysql/var/
innodb_log_arch_dir = /usr/local/mysql/var/
innodb_mirrored_log_groups = 1
innodb_log_files_in_group = 3
innodb_log_file_size = 5M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_log_archive = 0
innodb_buffer_pool_size = 16M
innodb_additional_mem_pool_size = 2M
innodb_file_io_threads = 4
innodb_lock_wait_timeout = 50

關鍵：innodb_data_home_dir 目錄需預先建立且 mysql 可寫 (mkdir var; chown mysql.mysql var; chmod g+w var)

驗證交易是否生效

mysql> SHOW VARIABLES LIKE 'have_%';
+----------------+-------+
| Variable_name  | Value |
+----------------+-------+
| have_innodb    | YES   |  <-- 關鍵
| have_bdb       | YES   |
+----------------+-------+

mysql> CREATE DATABASE innodb;
mysql> USE innodb;
mysql> CREATE TABLE customer (a INT, b CHAR(20), INDEX(a)) TYPE=InnoDB;
mysql> SET AUTOCOMMIT=0;
mysql> INSERT INTO customer VALUES(0,'Rainman');
mysql> COMMIT;
mysql> INSERT INTO customer VALUES(1,'Rainman2');
mysql> SELECT * FROM customer;  -- 2 列
mysql> ROLLBACK;
mysql> SELECT * FROM customer;  -- 回滾後僅 1 列

看到 have_innodb = YES 且 ROLLBACK 生效，即代表交易支援已就緒。