https://plumephp.com/tags/%E9%94%81/Recent content in 锁 on PlumePHPHugozh-CNFri, 14 Aug 2026 16:06:00 +0800https://plumephp.com/database-locking/Fri, 14 Aug 2026 16:06:00 +0800https://plumephp.com/database-locking/<h2 id="1-锁粒度">1. 锁粒度</h2> <table> <thead> <tr> <th>锁类型</th> <th>粒度</th> <th>并发度</th> <th>开销</th> <th>代表</th> </tr> </thead> <tbody> <tr> <td><strong>表锁</strong></td> <td>整张表</td> <td>最低</td> <td>最低</td> <td>MyISAM</td> </tr> <tr> <td><strong>页锁</strong></td> <td>一页（通常 4KB/8KB）</td> <td>中等</td> <td>中等</td> <td>BDB</td> </tr> <tr> <td><strong>行锁</strong></td> <td>单行记录</td> <td>最高</td> <td>最高</td> <td>InnoDB</td> </tr> </tbody> </table> <blockquote> <p>InnoDB 默认使用<strong>行锁</strong>，但在特定场景下会退化为表锁（如未命中索引的全表扫描）。</p>