SQL Server性能常用语句

1. 查看各表的数据行数
   

   SELECT
   
   o.name, i. ROWS
   
   FROM sysobjects o, sysindexes i
   
   WHERE o.id = i.id  AND o.Xtype = 'U' AND i.indid < 2
   
   ORDER BY o.name;

2. 计算数据库中各个表每行记录所占用空间
   

   --SELECT * FROM Employees AS e;
   
   
   
   CREATE TABLE #tablespaceinfo
   
       (
   
         nameinfo VARCHAR(50) ,
   
         rowsinfo BIGINT ,
   
         reserved VARCHAR(20) ,
   
         datainfo VARCHAR(20) ,
   
         index_size VARCHAR(20) ,
   
         unused VARCHAR(20)
   
       )  
   
    
   
   DECLARE @tablename VARCHAR(255);  
   
    
   
   DECLARE Info_cursor CURSOR
   
   FOR
   
       SELECT  '[' + [name] + ']'
   
       FROM    sys.tables
   
       WHERE   type = 'U';  
   
    
   
   OPEN Info_cursor  
   
   FETCH NEXT FROM Info_cursor INTO @tablename  
   
    
   
   WHILE @@FETCH_STATUS = 0
   
       BEGIN 
   
           INSERT  INTO #tablespaceinfo
   
                   EXEC sp_spaceused @tablename  
   
           FETCH NEXT FROM Info_cursor  
   
       INTO @tablename  
   
       END 
   
    
   
   CLOSE Info_cursor  
   
   DEALLOCATE Info_cursor  
   
    
   
   --创建临时表
   
   CREATE TABLE [#tmptb]
   
       (
   
         TableName VARCHAR(50) ,
   
         DataInfo BIGINT ,
   
         RowsInfo BIGINT ,
   
         Spaceperrow  AS ( CASE RowsInfo
   
                            WHEN 0 THEN 0
   
                            ELSE CAST(DataInfo AS decimal(18,2))/CAST(RowsInfo AS decimal(18,2))
   
                          END ) PERSISTED
   
       )
   
   
   
   --插入数据到临时表
   
   INSERT  INTO [#tmptb]
   
           ( [TableName] ,
   
             [DataInfo] ,
   
             [RowsInfo]
   
           )
   
           SELECT  [nameinfo] ,
   
                   CAST(REPLACE([datainfo], 'KB', '') AS BIGINT) AS 'datainfo' ,
   
                   [rowsinfo]
   
           FROM    #tablespaceinfo
   
           ORDER BY CAST(REPLACE(reserved, 'KB', '') AS INT) DESC  
   
   
   
   
   
   --汇总记录
   
   SELECT  [tbspinfo].* ,
   
           [tmptb].[Spaceperrow] AS '每行记录大概占用空间（KB）'
   
   FROM    [#tablespaceinfo] AS tbspinfo ,
   
           [#tmptb] AS tmptb
   
   WHERE   [tbspinfo].[nameinfo] = [tmptb].[TableName]
   
   ORDER BY CAST(REPLACE([tbspinfo].[reserved], 'KB', '') AS INT) DESC  
   
   
   
   DROP TABLE [#tablespaceinfo]
   
   DROP TABLE [#tmptb]

3. 获取SQL语句执行时

 

　　　　

DECLARE @a DATETIME

DECLARE @b DATETIME

SELECT @a=GETDATE()

exec sp_tables;        --查看表

SELECT @b=GETDATE()

SELECT @b-@a