CREATE DATABASE foo; GO USE foo; GO CREATE TABLE t1 (c1 INT IDENTITY, c2 CHAR (1000) DEFAULT 'a'); CREATE CLUSTERED INDEX t1c1 ON t1 (c1); GO SET NOCOUNT ON; GO INSERT INTO t1 DEFAULT VALUES; GO 10000
接下來設置填充因子為0并重建索引
復制代碼 代碼如下:
SELECT [fill_factor] FROM sys.indexes WHERE NAME = 't1c1' AND [object_id] = OBJECT_ID ('t1'); GO ALTER INDEX t1c1 ON t1 REBUILD WITH (FILLFACTOR = 100); GO
上面的代碼執行后，通過查看既定頁中的m_freeCnt列的值，也就是頁中可用空間的值:
復制代碼 代碼如下:
EXEC sp_allocationMetadata 't1'; GO DBCC TRACEON (3604); DBCC PAGE (foo, 1, 164, 3); -- the root page, from the SP output GO DBCC PAGE (foo, 1, 162, 1); -- the page ID in the DBCC PAGE output above GO
通過上面代碼可以看到值為10，也就是說業內不存在保留空間。這時一個誤區，有關上面sp_allocationMetadata的實現細節請看這篇博文:this blog post。
