sql server查询IO消耗大的排查sql诊断语句

sql server查询IO消耗大的排查sql诊断语句

1425发表于2019-04-01

前段时间网站访问量增大,云服务器后台监控告警提示IOPS过大。我使用以下sql语句很快就找到sql server占用IO在的相关功能模块。


select top 50 
    (total_logical_reads/execution_count) as avg_logical_reads,
    (total_logical_writes/execution_count) as avg_logical_writes,
    (total_physical_reads/execution_count) as avg_phys_reads,
     Execution_count, 
    statement_start_offset as stmt_start_offset, statement_end_offset as stmt_end_offset,
substring(sql_text.text, (statement_start_offset/2), 
case 
when (statement_end_offset -statement_start_offset)/2 <=0 then 64000
else (statement_end_offset -statement_start_offset)/2 end) as exec_statement,  sql_text.text,plan_text.*
from sys.dm_exec_query_stats  
cross apply sys.dm_exec_sql_text(sql_handle) as sql_text
cross apply sys.dm_exec_query_plan(plan_handle) as plan_text
order by 
--(total_logical_reads + total_logical_writes) /Execution_count Desc
 (total_logical_reads + total_physical_reads) /Execution_count Desc

可以找到avg_pshs_reads比较大的行,从text字段把对应的sql语句赋值出来。

常用的两种解决办法:

1、优化对应的sql语句(比如增加索引)

2、使用缓存


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