轉自:http://blog.rdiframework.net/244.html
數據庫隨着使用時間,若不進行相應管理就會越來越慢,優化數據庫方法很多,在此不介紹,說一下,如何自動對其索引產生的碎片進行自動重建,索引碎片的增多,有什麼影響,在此不闡述!
直接看代碼~!節約時間。
執行此查詢需注意以下幾點:
1)、需要 VIEW DATABASE STATE 權限。
2)、在不指定數據庫名稱的情況下,指定 DB_ID 作爲第一個參數。
3)、確定當前數據庫爲80以上。
*/
USE MASTER
SET NOCOUNT ON;
DECLARE @objectid int;
DECLARE @indexid int;
DECLARE @partitioncount bigint;
DECLARE @schemaname nvarchar(130);
DECLARE @objectname nvarchar(130);
DECLARE @indexname nvarchar(130);
DECLARE @partitionnum bigint;
DECLARE @partitions bigint;
DECLARE @frag float;
DECLARE @command nvarchar(4000);
— Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function
— and convert object and index IDs to names.
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 (db_id(‘TABLE_NAME‘), 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.
WHILE (1=1)
BEGIN;
FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag;
IF @@FETCH_STATUS < 0 BREAK;
SELECT @objectname = QUOTENAME(o.name), @schemaname = QUOTENAME(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 = QUOTENAME(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
SET @command = N‘ALTER INDEX ‘ + @indexname + N‘ ON ‘ + @schemaname + N‘.‘ + @objectname + N‘ REORGANIZE‘;
IF @frag >= 30.0
SET @command = N‘ALTER INDEX ‘ + @indexname + N‘ ON ‘ + @schemaname + N‘.‘ + @objectname + N‘ REBUILD‘;
IF @partitioncount > 1
SET @command = @command + N‘ PARTITION=‘ + CAST(@partitionnum AS nvarchar(10));
EXEC (@command);
PRINT N‘Executed: ‘ + @command;
END;
— Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions;
— Drop the temporary table.
DROP TABLE #work_to_do;
GO