SQL Server有哪些隐藏特性?

例如,没有文档的系统存储过程,做一些非常有用但没有足够文档的事情的技巧?


答案

感谢大家的精彩回答!

存储过程

sp_msforeachtable: Runs a command with '?' replaced with each table name (v6.5 and up) sp_msforeachdb: Runs a command with '?' replaced with each database name (v7 and up) sp_who2: just like sp_who, but with a lot more info for troubleshooting blocks (v7 and up) sp_helptext: If you want the code of a stored procedure, view & UDF sp_tables: return a list of all tables and views of database in scope. sp_stored_procedures: return a list of all stored procedures xp_sscanf: Reads data from the string into the argument locations specified by each format argument. xp_fixeddrives:: Find the fixed drive with largest free space sp_help: If you want to know the table structure, indexes and constraints of a table. Also views and UDFs. Shortcut is Alt+F1

片段

Returning rows in random order All database User Objects by Last Modified Date Return Date Only Find records which date falls somewhere inside the current week. Find records which date occurred last week. Returns the date for the beginning of the current week. Returns the date for the beginning of last week. See the text of a procedure that has been deployed to a server Drop all connections to the database Table Checksum Row Checksum Drop all the procedures in a database Re-map the login Ids correctly after restore Call Stored Procedures from an INSERT statement Find Procedures By Keyword Drop all the procedures in a database Query the transaction log for a database programmatically.

功能

哈希字节() EncryptByKey 枢轴命令

Misc

Connection String extras TableDiff.exe Triggers for Logon Events (New in Service Pack 2) Boosting performance with persisted-computed-columns (pcc). DEFAULT_SCHEMA setting in sys.database_principles Forced Parameterization Vardecimal Storage Format Figuring out the most popular queries in seconds Scalable Shared Databases Table/Stored Procedure Filter feature in SQL Management Studio Trace flags Number after a GO repeats the batch Security using schemas Encryption using built in encryption functions, views and base tables with triggers


当前回答

Persisted-computed-columns

计算列可以帮助您将运行时计算成本转移到数据修改阶段。计算列与行其余部分一起存储,当计算列上的表达式与查询匹配时,将透明地使用它。您还可以在PCC上构建索引,以加快表达式的过滤和范围扫描。

Link

其他回答

如果您想删除数据库中的所有过程-

SELECT  IDENTITY ( int, 1, 1 ) id, 
        [name] 
INTO    #tmp 
FROM    sys.procedures 
WHERE   [type]        = 'P' 
    AND is_ms_shipped = 0 

DECLARE @i INT 

SELECT   @i = COUNT( id ) FROM #tmp 
WHILE    @i > 0 
BEGIN 
   DECLARE @name VARCHAR( 100 ) 
   SELECT @name = name FROM #tmp WHERE id = @i 
   EXEC ( 'DROP PROCEDURE ' + @name ) 
   SET @i = @i-1 
END

DROP TABLE #tmp

跟踪旗帜!“1204”在SQL Server 2000上的死锁调试中是无价的(2005有更好的工具)。

强制参数化

参数化允许SQL Server利用查询计划重用,并避免后续执行类似查询时的编译和优化开销。然而,由于这样或那样的原因,仍然有许多应用程序存在特殊的查询编译开销。对于查询编译次数较多、降低CPU利用率和响应时间对工作负载至关重要的情况,强制参数化可以提供帮助。

Link

一个不太为人所知的TSQL技术,以随机顺序返回行:

-- Return rows in a random order
SELECT 
    SomeColumn 
FROM 
    SomeTable
ORDER BY 
    CHECKSUM(NEWID())

删除到数据库的所有连接:

Use Master
Go

Declare @dbname sysname

Set @dbname = 'name of database you want to drop connections from'

Declare @spid int
Select @spid = min(spid) from master.dbo.sysprocesses
where dbid = db_id(@dbname)
While @spid Is Not Null
Begin
        Execute ('Kill ' + @spid)
        Select @spid = min(spid) from master.dbo.sysprocesses
        where dbid = db_id(@dbname) and spid > @spid
End