注1: FOR UPDATE仅适用于InnoDB,且必须在交易区块(BEGIN/COMMIT)中才能生效。 注2: 要测试锁定的状况,可以利用MySQL的Command Mode ,开二个视窗来做测试。 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 锁超时时间 原文:Mysql事物锁等待超时 innodb_lock_wait_...
这ID与INFORMATION_SCHEMA PROCESSLIST表列中显示的PROCESSLIST_ID值、Performance Schemathreads 表列中显示的CONNECTION_ID()值以及线程内函数返回的值相同。User# MySQL 用户Host# 发出语句的客户端的主机名(除了system user没有主机的 )db# 线程的默认数据库Command# 线程代表客户端执行的命令类型,或者Sleep会话是否空...
从查看进程、确认进程 ID 到最终尝试正常或强制 kill 进程,提供了具体的 SQL 语句及其解释。 四、类图示例 以下是一个简单的类图,展示了 MySQL Process 及其操作方式: MySQLProcess+int id+string user+string command+int time+kill() : void+forceKill() : void 在这个类图中,表示每个 MySQL 进程的基本属性...
sql delete command: a) DELETE works much slower than TRUNCATE b) DELETE generates a small amount of redo and a large amount of undo c) Transaction log - for each deleted record (deletes rows one at a time and records an entry in the transaction log for each deleted row) - slower exec...
下面我们一步步来介绍 delete mysql 语法。 第一步:打开 MySQL 命令行工具 在 Windows 系统中,打开 MySQL 命令行工具的方法是首先在开始 菜单中搜索“mysql”,然后在搜索结果中找到并点击“MySQL 8.0 Command Line Client”图标。如果你使用的是 Mac 或 Linux 系统,则 可以通过打开终端应用来进入 MySQL 命令行...
User# MySQL 用户 Host # 发出语句的客户端的主机名(除了systemuser没有主机的 ) db # 线程的默认数据库 Command # 线程代表客户端执行的命令类型,或者Sleep会话是否空闲。 Time# 线程处于当前状态的时间(以秒为单位)。对于副本 SQL 线程,该值是上次复制事件的时间戳与副本主机的实时时间之间的秒数。
This command deletes the cluster named cluster_name, removing it from the list of clusters managed by MySQL Cluster Manager. delete cluster does not remove any MySQL NDB Cluster binaries from hosts. However, it does remove the cluster configuration, data, and log files that reside in the MyS...
execute(this=0x7fdcec006e28, thd=0x7fdcec000bc0) at /home/Code/GitHub/stonedb/sql/sql_delete.cc:1411#4 0x00000000023cba0c in mysql_execute_command(thd=0x7fdcec000bc0, first_level=true) at /home/Code/GitHub/stonedb/sql/sql_parse.cc:3655#5 0x00000000023d175d in mysql_parse...
(Supported in all NDB releases based on MySQL 8.0) --character-sets-dir Command-Line Format--character-sets-dir=path Removed8.0.31 Directory containing character sets. --connect-retries Command-Line Format--connect-retries=# TypeInteger
I have a transaction table. Records are added regularly, perhaps 50,000 per day. When it got to 1,000,000 records, I decided to purge the 500,000 oldest. So I ran this simple command: DELETE FROM am_log WHERE id<500000 Then the fun began. It ran for 40 minutes. It caused timeout...