本文将向大家讲解一下怎样缩小 SQL Server 的数据库日志文件，比较简单，一看就能明白。
问：我的数据库实际大小为600MB，日志文件实际大小为33MB，但日志文件占用空间为2.8GB！我曾经试了几种方式，SHIRNK DATABASE，TRUNCATE LOG FILE， 都没办法将文件缩小。
答：你可以把下面的代码COPY到查询分析器里，然后修改其中的3个参数(数据库名，日志文件名，和目标日志文件的大小)，运行即可。
以下是引用片段：
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SET NOCOUNT ON
DECLARE @LogicalFileName sysname,
@MaxMinutes INT,
@NewSize INT
USE Marias
-- 要操作的数据库名
SELECT @LogicalFileName = 'Marias_log'
-- 日志文件名
@MaxMinutes = 10,
-- Limit on time allowed to wrap log.
@NewSize = 100
-- 你想设定的日志文件的大小(M)
-- Setup / initialize
DECLARE @OriginalSize int
SELECT @OriginalSize = size
FROM sysfiles
WHERE name = @LogicalFileName
SELECT 'Original Size of ' + db_name() + ' LOG is ' +
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' +
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'
FROM sysfiles
WHERE name = @LogicalFileName
CREATE TABLE DummyTrans
(DummyColumn char (8000) not null)
DECLARE @Counter INT,
@StartTime DATETIME,
@TruncLog VARCHAR(255)
SELECT @StartTime = GETDATE(),
@TruncLog = 'BACKUP LOG '
+ db_name() + ' WITH TRUNCATE_ONLY'
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)
AND (@OriginalSize * 8 /1024) > @NewSize
BEGIN -- Outer loop.
SELECT @Counter = 0
WHILE ((@Counter < @OriginalSize / 16)
AND (@Counter < 50000))
BEGIN -- update
INSERT DummyTrans VALUES ('Fill Log')
DELETE DummyTrans
SELECT @Counter = @Counter + 1
END
EXEC (@TruncLog)
END
SELECT 'Final Size of ' + db_name() + ' LOG is ' +
CONVERT(VARCHAR(30),size) + ' 8K pages or ' +
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB'
FROM sysfiles
WHERE name = @LogicalFileName
DROP TABLE DummyTrans
SET NOCOUNT OFF
