常用SQL

1.查找逻辑读取最高的查询

SELECT TOP ( 25 )
p.name AS [SP Name] ,
deps.total_logical_reads AS [TotalLogicalReads] ,
deps.total_logical_reads / deps.execution_count AS [AvgLogicalReads] ,
deps.execution_count ,
ISNULL(deps.execution_count / DATEDIFF(SECOND, deps.cached_time,
GETDATE()), 0) AS [Calls/Second] ,
deps.total_elapsed_time ,
deps.total_elapsed_time / deps.execution_count AS [avg_elapsed_time] ,
deps.cached_time
FROM sys.procedures AS p
INNER JOIN sys.dm_exec_procedure_stats AS deps ON p.[object_id] = deps.[object_id]
WHERE deps.database_id = DB_ID()
ORDER BY deps.total_logical_reads DESC;

-- 当前数据库文件的I/O 统计信息
SELECT DB_NAME(DB_ID()) AS [Database Name] ,
[file_id] ,
num_of_reads ,
num_of_writes ,
num_of_bytes_read ,
num_of_bytes_written ,
CAST(100. * num_of_reads / ( num_of_reads + num_of_writes ) AS DECIMAL(10,
1)) AS [# Reads Pct] ,
CAST(100. * num_of_writes / ( num_of_reads + num_of_writes ) AS DECIMAL(10,
1)) AS [# Write Pct] ,
CAST(100. * num_of_bytes_read / ( num_of_bytes_read
+ num_of_bytes_written ) AS DECIMAL(10,
1)) AS [Read Bytes Pct] ,
CAST(100. * num_of_bytes_written / ( num_of_bytes_read
+ num_of_bytes_written ) AS DECIMAL(10,
1)) AS [Written Bytes Pct]
FROM sys.dm_io_virtual_file_stats(DB_ID(), NULL);

---查找CPU最高消耗的10个语句

SELECT TOP ( 10 )
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) AS statement_text ,
execution_count ,
total_worker_time / 1000 AS total_worker_time_ms ,
( total_worker_time / 1000 ) / execution_count AS avg_worker_time_ms ,
total_logical_reads ,
total_logical_reads / execution_count AS avg_logical_reads ,
total_elapsed_time / 1000 AS total_elapsed_time_ms ,
( total_elapsed_time / 1000 ) / execution_count AS avg_elapsed_time_ms ,
qp.query_plan
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st
CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp
ORDER BY total_worker_time DESC