在一个大型数据库中，数据的更改是非常频繁的。
而建立在这些数据上的索引也是需要经常去维护的。
否则这这些数据索引就起不到起应起的作用。甚至会成为数据库本身的负担。
我们就要定期的对数据库的索引进行维护 我在MSDN上发现了这个脚本不过其中有些小问题我已经修正 大家可以使用这个脚本对数据库的索引进行日常维护
复制代码 代码如下:
SET NOCOUNT ON;
DECLARE @objectid int;
DECLARE @indexid int;
DECLARE @partitioncount bigint;
DECLARE @schemaname sysname;
DECLARE @objectname sysname;
DECLARE @indexname sysname;
DECLARE @partitionnum bigint;
DECLARE @partitions bigint;
DECLARE @frag float;
DECLARE @command varchar(8000);
DECLARE @dbId int;
-- ensure the temporary table does not exist
IF EXISTS (SELECt name FROM sys.objects WHERe name = 'work_to_do')
DROp TABLE work_to_do;
-- conditionally select from the function, converting object and index IDs to names.
set @dbId=DB_ID();
SELECt
object_id AS objectid,
index_id AS indexid,
partition_number AS partitionnum,
avg_fragmentation_in_percent AS frag
INTO work_to_do FROM sys.dm_db_index_physical_stats (@dbId, NULL, NULL , NULL, 'LIMITED')
WHERe avg_fragmentation_in_percent > 10.0 AND index_id > 0;
-- Declare the cursor for the list of partitions to be processed.
DECLARE partitions CURSOR FOR SELECt * FROM work_to_do;
-- Open the cursor.
OPEN partitions;
-- Loop through the partitions.
FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag;
WHILE @@FETCH_STATUS = 0
BEGIN;
SELECt @objectname = o.name, @schemaname = s.name
FROM sys.objects AS o
JOIN sys.schemas as s ON s.schema_id = o.schema_id
WHERe o.object_id = @objectid;
SELECt @indexname = name
FROM sys.indexes
WHERe object_id = @objectid AND index_id = @indexid;
SELECt @partitioncount = count (*)
FROM sys.partitions
WHERe object_id = @objectid AND index_id = @indexid;
-- 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding
IF @frag < 30.0
BEGIN;
SELECt @command = 'ALTER INDEX [' + @indexname + '] ON ' + @schemaname + '.[' + @objectname + '] REORGANIZE';
IF @partitioncount > 1
SELECT @command = @command + ' PARTITION=' + ConVERT (CHAR, @partitionnum);
EXEC (@command);
END;
IF @frag >= 30.0
BEGIN;
SELECT @command = 'ALTER INDEX [' + @indexname +'] ON ' + @schemaname + '.[' + @objectname + '] REBUILD';
IF @partitioncount > 1
SELECT @command = @command + ' PARTITION=' + ConVERT (CHAR, @partitionnum);
EXEC (@command);
END;
PRINT 'Executed ' + @command;
FETCH NEXT FROM partitions INTO @objectid, @indexid, @partitionnum, @frag;
END;
-- Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions;
-- drop the temporary table
IF EXISTS (SELECT name FROM sys.objects WHERe name = 'work_to_do')
DROP TABLE work_to_do;
GO
这个脚本在运行时 会建立一个表 work_to_do 整理完毕后会自动删除这个表。如果大家不喜欢这样的话也可以用 一个 临时表解决 .
