有关日志压缩

SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS OFF
GO

CREATE PROCEDURE strink_logspace
 AS
   SET NOCOUNT ON
   DECLARE @LogicalFileName sysname,
           @MaxMinutes INT,
           @NewSize INT

   SELECT  @LogicalFileName = rtrim(name),
           @MaxMinutes = 10,      -- 最大执行时间
           @NewSize    = 10       -- 最小空间
   from sysfiles where status & 0x40 = 0x40

   -- Setup / initialize
   DECLARE @OriginalSize int
   SELECT @OriginalSize = size -- in 8K pages
     FROM sysfiles
     WHERE name = @LogicalFileName

   SELECT db_name() +'日志原始大小' + 
           CONVERT(VARCHAR(30),@OriginalSize) + ' pages/ 8K 或 ' +
           CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'
     FROM sysfiles
     WHERE name = @LogicalFileName

   CREATE TABLE DummyTrans
     (DummyColumn char (8000) not null)

   -- Wrap log and truncate it.
   DECLARE @Counter   INT,
           @StartTime DATETIME,
           @TruncLog  VARCHAR(255)
   SELECT  @StartTime = GETDATE(),
           @TruncLog = 'BACKUP LOG ['+ db_name() + '] WITH TRUNCATE_ONLY'
   -- Try an initial shrink.
   DBCC SHRINKFILE (@LogicalFileName, @NewSize)

   EXEC (@TruncLog)

   -- Wrap the log if necessary.
   WHILE     @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired
         AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName)  -- the log has not shrunk   
         AND (@OriginalSize * 8 /1024) > @NewSize  -- The value passed in for new size is smaller than the current size.
     BEGIN -- Outer loop.
       SELECT @Counter = 0
       WHILE  ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))
         BEGIN -- update
           INSERT DummyTrans VALUES ('Fill Log')  -- Because it is a char field it inserts 8000 bytes.
           DELETE DummyTrans
           SELECT @Counter = @Counter + 1
         END   -- update
       EXEC (@TruncLog)  -- See if a trunc of the log shrinks it.
     END   -- outer loop

   DBCC SHRINKFILE (@LogicalFileName, @NewSize)

   SELECT db_name() +'日志最后大小' +
           CONVERT(VARCHAR(30),size) + ' pages/ 8K 或  ' +
           CONVERT(VARCHAR(30),(size*8/1024)) + 'MB'
     FROM sysfiles
     WHERE name = @LogicalFileName
   DROP TABLE DummyTrans
   PRINT '*** 数据库日志压缩成功 ***'
   SET NOCOUNT OFF

GO
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO

--used
exec strink_logspace