加入收藏 | 设为首页 | 会员中心 | 我要投稿 滁州站长网 (https://www.0550zz.com/)- 科技、建站、经验、云计算、5G、大数据,站长网!
当前位置: 首页 > 站长学院 > MySql教程 > 正文

MySQL sys库常用的SQL命令整理

发布时间:2022-01-17 13:53:10 所属栏目:MySql教程 来源:互联网
导读:本篇内容主要讲解MySQL sys库常用的SQL命令整理,感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷,实用性强。下面就让小编来带大家学习MySQL sys库常用的SQL命令整理吧! 查看当前连接情况: select host, current_connections,statements from sys.h
       本篇内容主要讲解“MySQL sys库常用的SQL命令整理”,感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷,实用性强。下面就让小编来带大家学习“MySQL sys库常用的SQL命令整理”吧!
 
查看当前连接情况:
 
       select host, current_connections,statements from sys.host_summary;
 
查看当前正在执行的SQL:
 
       select conn_id, user, current_statement, last_statement from sys.session;
 
查看系统里执行最多的TOP 10 SQL:
 
select * from sys.statement_analysis order by exec_count desc limit 10 G
 
查看系统里哪张表的IO最多:
 
select * from sys.io_global_by_file_by_bytes limit 10;
 
查看系统里哪张表访问次数最多:
 
select * from sys.statement_analysis order by exec_count desc limit 10 G
 
查看哪些语句延迟比较严重:
 
select * from sys.statement_analysis order by avg_latency desc limit 10 G
 
查看系统里未使用过的索引:
 
select * from sys.schema_unused_indexes;
 
查看系统里冗余的索引:
 
select table_schema,table_name,redundant_index_name,redundant_index_columns,dominant_index_name,dominant_index_columns from sys.schema_redundant_indexes;
 
哪些SQL语句使用了磁盘临时表:
 
select db, query, tmp_tables,tmp_disk_tables from sys.statement_analysis where tmp_tables>0 or tmp_disk_tables >0 order by(tmp_tables+tmp_disk_tables) desc limit 20;
 
查看哪张表占用了最多的buffer pool:
 
select * from sys.innodb_buffer_stats_by_table order by pages desc limit 10 G
 
查看每个库占用多少buffer pool:
 
select * from sys.innodb_buffer_stats_by_schema;
 
查看每个连接分配多少内存:
 
select b.user, current_count_used,current_allocated, current_avg_alloc, current_max_alloc,total_allocated,current_statement from sys.memory_by_thread_by_current_bytes a,sys.session b where a.thread_id = b.thd_id;
 
查看MySQL内部的线程类型及数量:
 
select user, count(*) from sys.processlist group by user;
 
查看表自增ID情况:
 
select * from sys.schema_auto_increment_columns limit 10;
 
附:sys库视图和指标详解
 
视图                                                                                  说明
 
host_summary,x $ host_summary                                统计以主机为分组统计活动的语句,文件I / O,连接等信息
 
host_summary_by_file_io,x $ host_summary_by_file_io                 文件IO
 
host_summary_by_file_io_type,x $ host_summary_by_file_io_type       主机和事件类型的文件I / O
 
host_summary_by_stages,x $ host_summary_by_stages                  按照主机分类的语句阶段执行信息
 
host_summary_by_statement_latency,x $ host_summary_by_statement_latency按照主机分类的语句统计
 
host_summary_by_statement_type,x $ host_summary_by_statement_type      按照主机和SQL执行的语句信息
 
innodb_buffer_stats_by_schema,x $ innodb_buffer_stats_by_schema      按照架构统计InnoDB缓冲区信息
 
innodb_buffer_stats_by_table,x $ innodb_buffer_stats_by_table        按照schema和表统计InnoDB缓冲区信息
 
innodb_lock_waits,x $ innodb_lock_waits                                 InnoDB锁锁信息
 
io_by_thread_by_latency,x $ io_by_thread_by_latency                       线程消耗IO
 
io_global_by_file_by_bytes,x $ io_global_by_file_by_bytes                文件IO消耗大小信息
 
io_global_by_file_by_latency,x $ io_global_by_file_by_latency            文件IO延迟信息
 
io_global_by_wait_by_bytes,x $ io_global_by_wait_by_bytes              按照大小(字节)的全局I / O消耗
 
io_global_by_wait_by_latency,x $ io_global_by_wait_by_latency          IO消耗的延迟信息
 
latest_file_io,x $ latest_file_io                                      最近使用文件I / O信息
 
memory_by_host_by_current_bytes,x $ memory_by_host_by_current_bytes    主机使用内存信息
 
memory_by_thread_by_current_bytes,x $ memory_by_thread_by_current_bytes线程使用内存信息
 
memory_by_user_by_current_bytes,x $ memory_by_user_by_current_bytes         用户使用内存信息
 
memory_global_by_current_bytes,x $ memory_global_by_current_bytes             内存使用分配的类型
 
memory_global_total,x $ memory_global_total                                   内存统计信息
 
指标说明                                                                                                            
 
processlist,x $ processlist                                                Processlist进程信息
 
ps_check_lost_instrumentation                                                 丢失的性能模式工具的信息
 
schema_auto_increment_columns                                                   AUTO_INCREMENT自增长列信息
 
schema_index_statistics,x $ schema_index_statistics                         索引统计信息
 
schema_object_overview                                                         每个模式的对象类型
 
schema_redundant_indexes                                                       重复/冗余的索引
 
schema_table_lock_waits,x $ schema_table_lock_waits                             等待MDL的会话
 
schema_table_statistics,x $ schema_table_statistics                            表统计信息
 
schema_table_statistics_with_buffer,x $ schema_table_statistics_with_buffer表统计信息,包含InnoDB缓冲池统计信息
 
schema_tables_with_full_table_scans,x $ schema_tables_with_full_table_scans全表访问的表
 
schema_unused_indexes                                                           没有使用的索引
 
session,x $ session                                                          用户会话的Processlis信息
 
session_ssl_status                                                                SSL连接信息
 
statement_analysis,x $ statement_analysis                                      SQL语句汇总信息统计
 
statements_with_errors_or_warnings,x $ statements_with_errors_or_warnings       含有错误和警告的SQL
 
statements_with_full_table_scans,x $ statements_with_full_table_scans            执行时候全表扫描的语句
 
statements_with_runtimes_in_95th_percentile,X $ statements_with_runtimes_in_95th_percentile平均运行时间很长的SQL
 
statements_with_sorting,x $ statements_with_sorting                                       排序的SQL语句
 
statements_with_temp_tables,x $ statements_with_temp_tables                         使用临时表的SQL玉溪
 
user_summary,x $ user_summary                                                       用户语句和活动连接信息
 
user_summary_by_file_io,x $ user_summary_by_file_io                                 用户相关文件I / O信息
 
user_summary_by_file_io_type,x $ user_summary_by_file_io_type                         用户相关文件FI / O类型信息
 
user_summary_by_stages,x $ user_summary_by_stages                                     用户阶段事件和延迟信息
 
user_summary_by_statement_latency,x $ user_summary_by_statement_latency            以统计的SQL语句信息
 
user_summary_by_statement_type,x $ user_summary_by_statement_type                  按照用户和事件(事件)已执行的SQL语句信息
 
wa_ wait_classes_global_by_avg_latency                                              事件类型分类的平均延迟
 
wait_classes_global_by_latency,x $ wait_classes_global_by_latency                  事件类型的延迟统计
 
waits_by_host_by_latency,x $ waits_by_host_by_latency                              按照主机分类的事件系想你
 
waits_by_user_by_latency,x $ waits_by_user_by_latency                              按用户统计的事件
 
waits_global_by_latency,x $ waits_global_by_latency                              按事件统计的事件信息
 
到此,相信大家对“MySQL sys库常用的SQL命令整理”有了更深的了解,不妨来实际操作一番吧!

(编辑:滁州站长网)

【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容!

    热点阅读