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名自己的选择索引

2016-07-25 21:31 211 查看
禁用索引:

ALTER INDEX [IX_TransactionHistory_ReferenceOrderID_ReferenceOrderLineID]
ON [Production].[TransactionHistory] DISABLE

创建索引:

CREATE NONCLUSTERED INDEX
[IX2_TransactionHistory_ReferenceOrderLineID_ReferenceOrderID]
ON [Production].[TransactionHistory]
(
[ReferenceOrderLineID] ASC,
[ReferenceOrderID] ASC

);

启用索引:

ALTER INDEX [IX_TransactionHistory_ReferenceOrderID_ReferenceOrderLineID]
ON [Production].[TransactionHistory] REBUILD;

删除索引:

drop index [IX2_TransactionHistory_ReferenceOrderLineID_ReferenceOrderID]
ON [Production].[TransactionHistory]

选择群集索引:

默认情况下,主键是和群击索引一期创建的,如果不想把主键声明为群集索引,那么在创建表时只需要添加关键字NONCLUSTERED。

例:CREATE TABLE MyTableExample(
Column1 int IDENTITY
PRIMARY KEY NONCLUSTERED,
Column2 int
)
注:一旦创建了索引,改变他的唯一方法就是删除和重建他。

创建一个过滤索引:

CREATE INDEX ix_SalesOrderDetail_ProductID_filt_SpecialOffers
ON Sales.SalesOrderDetail (ProductID)
WHERE SpecialOfferID > 1;


sys.dm_db_index_physical_stats元数据函数有助于确定数据库中的页和区段有多满:

例:

DECLARE @db_id SMALLINT;
DECLARE @object_id INT;
SET @db_id = DB_ID(N'AdventureWorks');
SET @object_id = OBJECT_ID(N'AdventureWorks.Sales.SalesOrderDetail');
SELECT database_id, object_id, index_id, index_depth, avg_fragmentation_in_percent,
page_count
FROM sys.dm_db_index_physical_stats(@db_id,@object_id,NULL,NULL,NULL);
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