189 lines
5.4 KiB
SQL
189 lines
5.4 KiB
SQL
-- ================================================
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-- 导入性能优化SQL
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-- 功能：添加必要的索引，提升导入速度
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-- 执行前：备份数据库
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-- ================================================
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USE study;
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-- ================================================
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-- 1. 检查现有索引
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-- ================================================
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-- 查看 sys_user 表的索引
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SHOW INDEX FROM sys_user;
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-- 查看 student_class 表的索引
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SHOW INDEX FROM student_class;
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-- ================================================
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-- 2. 添加索引
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-- ================================================
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-- 为 sys_user 表添加索引
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-- 用于快速按信息编号（user_name）查询用户
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-- 如果索引已存在会报错，可以忽略
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ALTER TABLE sys_user ADD INDEX idx_user_name (user_name);
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-- 用于快速按用户名（nick_name）查询
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ALTER TABLE sys_user ADD INDEX idx_nick_name (nick_name);
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-- 用于快速按监区查询
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ALTER TABLE sys_user ADD INDEX idx_prison_area (prison_area);
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-- 为 student_class 表添加索引
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-- 用于快速按学员ID查询班级
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ALTER TABLE student_class ADD INDEX idx_student_id (student_id);
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-- 用于快速按班级ID查询学员
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ALTER TABLE student_class ADD INDEX idx_class_id (class_id);
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-- 用于快速按状态查询
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ALTER TABLE student_class ADD INDEX idx_status (status);
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-- 复合索引：学员ID + 状态（常用查询组合）
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ALTER TABLE student_class ADD INDEX idx_student_status (student_id, status);
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-- ================================================
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-- 3. 优化已有索引（如果需要）
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-- ================================================
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-- 检查唯一键是否已优化
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SHOW INDEX FROM student_class WHERE Key_name = 'uk_student_class';
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-- 如果唯一键不包含 status，可能需要重建
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-- 注意：重建索引前请先备份数据！
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-- ALTER TABLE student_class DROP INDEX uk_student_class;
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-- ALTER TABLE student_class ADD UNIQUE INDEX uk_student_class (student_id, class_id);
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-- ================================================
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-- 4. 分析表统计信息
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-- ================================================
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-- 更新表统计信息，帮助查询优化器选择更好的执行计划
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ANALYZE TABLE sys_user;
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ANALYZE TABLE student_class;
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ANALYZE TABLE study_class;
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-- ================================================
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-- 5. 验证索引效果
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-- ================================================
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-- 测试查询1：按user_name查询（应该使用idx_user_name）
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EXPLAIN SELECT * FROM sys_user WHERE user_name = '201';
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-- 测试查询2：按student_id查询班级（应该使用idx_student_id）
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EXPLAIN SELECT * FROM student_class WHERE student_id = 234;
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-- 测试查询3：按student_id和status查询（应该使用idx_student_status）
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EXPLAIN SELECT * FROM student_class WHERE student_id = 234 AND status = 1;
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-- ================================================
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-- 6. 清理慢查询日志（可选）
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-- ================================================
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-- 查看慢查询日志设置
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SHOW VARIABLES LIKE 'slow_query%';
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SHOW VARIABLES LIKE 'long_query_time';
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-- 临时设置慢查询阈值为1秒（用于监控）
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SET GLOBAL long_query_time = 1;
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-- 清空慢查询日志（可选）
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-- TRUNCATE mysql.slow_log;
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-- ================================================
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-- 7. 检查表碎片（可选）
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-- ================================================
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-- 查看表信息
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SELECT
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table_name,
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table_rows,
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data_length,
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index_length,
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data_free
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FROM information_schema.TABLES
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WHERE table_schema = 'study'
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AND table_name IN ('sys_user', 'student_class');
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-- 如果data_free较大，可以优化表
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-- OPTIMIZE TABLE sys_user;
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-- OPTIMIZE TABLE student_class;
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-- ================================================
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-- 8. 检查并优化字段类型（可选）
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-- ================================================
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-- 查看字段定义
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DESCRIBE sys_user;
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DESCRIBE student_class;
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-- 建议：
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-- 1. user_name (信息编号) 建议使用 VARCHAR(50) 而不是 VARCHAR(255)
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-- 2. 日期字段使用 DATE 而不是 DATETIME（如果不需要时间）
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-- 3. 状态字段使用 TINYINT 而不是 INT
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-- ================================================
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-- 9. 性能监控查询
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-- ================================================
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-- 查看当前正在执行的查询
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SELECT
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id,
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user,
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host,
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db,
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command,
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time,
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state,
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info
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FROM information_schema.processlist
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WHERE command != 'Sleep'
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ORDER BY time DESC;
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-- 查看慢查询统计
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SELECT
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count(*) as slow_query_count,
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sql_text
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FROM mysql.slow_log
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GROUP BY sql_text
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ORDER BY slow_query_count DESC
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LIMIT 10;
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-- ================================================
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-- 10. 导入性能测试
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-- ================================================
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-- 测试前记录时间
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SELECT NOW() as test_start_time;
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-- 执行导入操作...
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-- 测试后记录时间
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SELECT NOW() as test_end_time;
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-- 查看慢查询
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SELECT * FROM mysql.slow_log
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WHERE start_time > '2025-12-05 14:00:00'
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ORDER BY query_time DESC
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LIMIT 20;
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-- ================================================
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-- 完成！
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-- ================================================
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-- 验证索引已创建
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SELECT
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TABLE_NAME,
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INDEX_NAME,
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COLUMN_NAME,
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SEQ_IN_INDEX
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FROM information_schema.STATISTICS
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WHERE TABLE_SCHEMA = 'study'
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AND TABLE_NAME IN ('sys_user', 'student_class')
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ORDER BY TABLE_NAME, INDEX_NAME, SEQ_IN_INDEX;
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-- 显示优化建议
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SELECT 'Indexes added successfully! Please test import performance.' AS result;
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