104 lines
3.2 KiB
SQL
104 lines
3.2 KiB
SQL
-- ================================================
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-- 系统性能诊断脚本
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-- ================================================
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USE study;
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-- ================================================
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-- 1. 检查当前正在运行的查询
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-- ================================================
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SELECT '检查当前运行的查询...' AS info;
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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 AS '执行时间(秒)',
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state AS '状态',
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LEFT(info, 100) AS 'SQL语句'
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FROM information_schema.processlist
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WHERE db = 'study'
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ORDER BY time DESC;
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-- ================================================
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-- 2. 检查表的索引数量（索引过多会导致INSERT/UPDATE变慢）
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-- ================================================
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SELECT '检查索引数量...' AS info;
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SELECT
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TABLE_NAME AS '表名',
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COUNT(DISTINCT INDEX_NAME) AS '索引数量',
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GROUP_CONCAT(DISTINCT INDEX_NAME) AS '索引列表'
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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', 'sys_user_role')
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GROUP BY TABLE_NAME
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ORDER BY COUNT(DISTINCT INDEX_NAME) DESC;
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-- ================================================
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-- 3. 检查表大小和行数
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-- ================================================
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SELECT '检查表大小...' AS info;
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SELECT
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TABLE_NAME AS '表名',
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TABLE_ROWS AS '行数',
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ROUND(DATA_LENGTH/1024/1024, 2) AS '数据大小(MB)',
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ROUND(INDEX_LENGTH/1024/1024, 2) AS '索引大小(MB)',
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ROUND((DATA_LENGTH+INDEX_LENGTH)/1024/1024, 2) AS '总大小(MB)'
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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', 'sys_user_role', 'study_class')
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ORDER BY (DATA_LENGTH+INDEX_LENGTH) DESC;
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-- ================================================
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-- 4. 检查是否有锁表
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-- ================================================
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SELECT '检查表锁...' AS info;
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SHOW OPEN TABLES WHERE In_use > 0;
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-- ================================================
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-- 5. 测试简单查询的性能
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-- ================================================
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SELECT '测试查询性能...' AS info;
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-- 测试1：简单SELECT
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SET @start_time = NOW(6);
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SELECT COUNT(*) FROM sys_user;
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SET @end_time = NOW(6);
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SELECT TIMESTAMPDIFF(MICROSECOND, @start_time, @end_time)/1000 AS '查询耗时(ms)';
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-- ================================================
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-- 6. 查看慢查询日志状态
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-- ================================================
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SELECT '慢查询配置...' AS info;
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SHOW VARIABLES LIKE 'slow_query%';
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SHOW VARIABLES LIKE 'long_query_time';
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-- ================================================
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-- 7. 检查数据库连接数
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-- ================================================
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SELECT '检查连接数...' AS info;
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SHOW STATUS LIKE 'Threads_connected';
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SHOW STATUS LIKE 'Max_used_connections';
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SHOW VARIABLES LIKE 'max_connections';
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-- ================================================
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-- 8. 详细查看 sys_user 表的所有索引
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-- ================================================
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SELECT '详细索引信息 - sys_user' AS info;
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SHOW INDEX FROM sys_user;
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-- ================================================
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-- 9. 详细查看 student_class 表的所有索引
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-- ================================================
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SELECT '详细索引信息 - student_class' AS info;
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SHOW INDEX FROM student_class;
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