sql常用sql(查询耗时sql、还原备份等)

1、查询耗时较久的sql语句

SELECT TOP 20
    total_worker_time/1000 AS [总消耗CPU 时间(ms)],execution_count [运行次数],
    qs.total_worker_time/qs.execution_count/1000 AS [平均消耗CPU 时间(ms)],
    last_execution_time AS [最后一次执行时间],max_worker_time /1000 AS [最大执行时间(ms)],
    SUBSTRING(qt.text,qs.statement_start_offset/2+1, 
        (CASE WHEN qs.statement_end_offset = -1 
        THEN DATALENGTH(qt.text) 
        ELSE qs.statement_end_offset END -qs.statement_start_offset)/2 + 1) 
    AS [使用CPU的语法], qt.text [完整语法],
    qt.dbid, dbname=db_name(qt.dbid),
    qt.objectid,object_name(qt.objectid,qt.dbid) ObjectName
FROM sys.dm_exec_query_stats qs WITH(nolock)
CROSS apply sys.dm_exec_sql_text(qs.sql_handle) AS qt
WHERE execution_count>1
ORDER BY  total_worker_time DESC

SELECT s2.dbid, 
s1.sql_handle, 
(SELECT TOP 1 SUBSTRING(s2.text,statement_start_offset / 2+1 , 
( (CASE WHEN statement_end_offset = -1 
THEN (LEN(CONVERT(nvarchar(max),s2.text)) * 2) 
ELSE statement_end_offset END) - statement_start_offset) / 2+1)) AS sql_statement,
execution_count, 
plan_generation_num, 
last_execution_time, 
total_worker_time, 
last_worker_time, 
min_worker_time, 
max_worker_time,
total_physical_reads, 
last_physical_reads, 
min_physical_reads, 
max_physical_reads, 
total_logical_writes, 
last_logical_writes, 
min_logical_writes, 
max_logical_writes 
FROM sys.dm_exec_query_stats AS s1 
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS s2 
WHERE s2.objectid is null 
ORDER BY last_worker_time desc,s1.sql_handle, s1.statement_start_offset, s1.statement_end_offset;

2、数据库还原

USE [master]
RESTORE DATABASE ETM_Cloud FROM  DISK = N'E:DB_backupETM_Cloud_FullBackup_2018_04_08_162313.bak' WITH  FILE = 1, 
MOVE N'ETM_Cloud' TO N'D:Program FilesMicrosoft SQL ServerMSSQL11.MSSQLSERVERMSSQLDATAETM_Cloud.mdf', 
MOVE N'ETM_Cloud_log' TO N'D:Program FilesMicrosoft SQL ServerMSSQL11.MSSQLSERVERMSSQLDATAETM_Cloud_log.ldf', 
NOUNLOAD,NORECOVERY,  REPLACE,  STATS = 5

GO


--注意一定要用NORECOVERY来还原备份
USE [master]
RESTORE DATABASE [ETM_Cloud] FROM  DISK = N'E:DB_backupETM_Cloud_logBackup_2018_04_08_162313.bak' WITH  FILE = 1, 
NOUNLOAD,NORECOVERY,  REPLACE,  STATS = 5

GO

3、日志清理(alwayson_clean_log)

--备份事务日志，备份成NUL，就不用占用硬盘空间
BACKUP LOG [ECloud] TO DISK='NUL:'
USE [ECloud]
GO
--收缩数据库日志文件
DBCC SHRINKFILE(ECloud_log,10)
GO