SQL Server調優--SQL慢查詢

查詢sql server慢查詢

SELECT creation_time  N'語句編譯時間'
        ,last_execution_time  N'上次執行時間'
        ,total_physical_reads N'物理讀取總次數'
        ,total_logical_reads/execution_count N'每次邏輯讀次數'
        ,total_logical_reads  N'邏輯讀取總次數'
        ,total_logical_writes N'邏輯寫入總次數'
        ,execution_count  N'執行次數'
        ,total_worker_time/1000 N'所用的CPU總時間ms'
        ,total_elapsed_time/1000  N'總花費時間ms'
        ,(total_elapsed_time / execution_count)/1000  N'平均時間ms'
        ,SUBSTRING(st.text, (qs.statement_start_offset/2) + 1,
         ((CASE statement_end_offset
          WHEN -1 THEN DATALENGTH(st.text)
          ELSE qs.statement_end_offset END
            - qs.statement_start_offset)/2) + 1) N'執行語句'
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st
where SUBSTRING(st.text, (qs.statement_start_offset/2) + 1,
         ((CASE statement_end_offset
          WHEN -1 THEN DATALENGTH(st.text)
          ELSE qs.statement_end_offset END
            - qs.statement_start_offset)/2) + 1) not like '%fetch%'
ORDER BY  total_elapsed_time / execution_count DESC;

View Code

找到消耗內存最多的SQL

SELECT mg.granted_memory_kb, mg.session_id, t.text, qp.query_plan 
FROM sys.dm_exec_query_memory_grants AS mg
CROSS APPLY sys.dm_exec_sql_text(mg.sql_handle) AS t
CROSS APPLY sys.dm_exec_query_plan(mg.plan_handle) AS qp
ORDER BY 1 DESC OPTION (MAXDOP 1)

 是不使用Not In，而使用Not Exists做爲替代