7.6.9.1 The Locking Service MySQL distributions provide a locking interface that is accessible at two levels: At the SQL level, as a set of loadable functions that each map onto calls to the service routines. As a C language interface, callable as a plugin service from server plugins or loa...
5.5.6.1 The Locking Service MySQL distributions provide a locking interface that is accessible at two levels: At the SQL level, as a set of loadable functions that each map onto calls to the service routines. As a C language interface, callable as a plugin service from server plugins or loa...
External locking is the use of file system locking to manage contention【kənˈtenʃn(尤指争论时的)看法,观点;争论;争执;争吵;】 for MyISAM database tables by multiple processes. External locking is used in situations where a single process such as the MySQL server cannot be assumed to ...
MySQL Transactional and Locking Commands BEGIN/COMMIT/ROLLBACK Syntax By default, MySQL runs in autocommit mode. This means that as soon as you execute an update, MySQL will store the update on … - Selection from MySQL Reference Manual [Book]
Gap locking is not needed for statements that lock rows using a unique index to search for a unique row. (This does not include the case that the search condition includes only some columns of a multiple-column unique index; in that case, gap locking does occur.) --这一段话,要嘻嘻揣摩...
skip-external-locking key_buffer_size = 16K max_allowed_packet = 1M table_open_cache = 4 sort_buffer_size = 64K read_buffer_size = 256K read_rnd_buffer_size = 256K net_buffer_length = 2K thread_stack = 128K # Don't listen on a TCP/IP port at all. This can be a security enha...
MySQL manual里还有一段: http://dev.mysql.com/doc/refman/5.6/en/innodb-next-key-locking.htmlAvoiding the Phantom Problem Using Next-Key Locking To prevent phantoms,InnoDB uses an algorithm called next-key locking that combines index-row locking with gap locking.You canusenext-key locking to imp...
InnoDB支持行级锁(row-level locking)和表级锁,默认为行级锁。 行级锁,表级锁和页级锁对比: 行级锁:MySQL中锁定粒度最细的一种锁,表示只针对当前操作的行进行加锁。行级锁能大大减少数据库操作的冲突。其加锁粒度最小,但加锁的开销也最大。锁定粒度最小,发生锁冲突的概率最低,并发度也最高。
场景:版本5.6.44,[ERROR] Fatal error: Please read "Security" section of the manual to find out how to run mysqld as root!此处 mysql是出于安全考虑,默认拒绝用root账号启动mysql服务。 解决1)通过在命令后面加上--user=root 进行强制使用root账号启动 ...
因此可见。 参考文献 MySQL 官方文档——consistent read MySQL 5.7 Reference Manual: Consistent Nonlocking Reads MySQL 5.7 Reference Manual: InnoDB Multi-Versioning MySQL中MVCC的正确打开方式(源码佐证) 附:MVCC与一致性无锁读脑图