1. Data Storage Challenges
For either client application or small-scale server applications, you need to address a number of data storage challenges:
 Data storage location. If you are building a distributed client application and can afford to store your data on a back-end server and retrieve the data over the network, you can just use SQL Server 2005 on the back end. If you are building a mobile device or client application, you will likely need a local data store on the client to cache data when you are offline. You may also need to cache on the client to avoid retrieving large datasets, such as a product catalog, repeatedly over the network. For client applications, the data may only be needed locally, in which case storing on a back-end server does not make sense.
1. 數(shù)據(jù)存儲挑戰(zhàn)
對于客戶端應(yīng)用程序或小規(guī)模服務(wù)器應(yīng)用程序，您需要解決很多數(shù)據(jù)存儲方面的挑戰(zhàn)：
• 數(shù)據(jù)存儲位置。如果您要構(gòu)建分布式客戶端應(yīng)用程序，并且可以承擔(dān)將數(shù)據(jù)存儲于后端服務(wù)器并通過網(wǎng)絡(luò)檢索數(shù)據(jù)的費(fèi)用，完全可以在服務(wù)器上使用 SQL Server 2005。如果要構(gòu)建移動設(shè)備或客戶端應(yīng)用程序，則可能需要在客戶端建立本地數(shù)據(jù)存儲，以便在脫機(jī)時緩存數(shù)據(jù)。同時您可能還需要在客戶端進(jìn)行緩存，以避免通過網(wǎng)絡(luò)重復(fù)檢索諸如產(chǎn)品目錄的大型數(shù)據(jù)集。對于客戶端應(yīng)用程序，可能只需在本地訪問數(shù)據(jù)，在這種情況下，將數(shù)據(jù)存儲在后端服務(wù)器上是沒有意義的。
• 數(shù)據(jù)的易訪問性。生產(chǎn)效率對于在預(yù)算內(nèi)將應(yīng)用程序按時推向市場來說是非常重要的。因此您應(yīng)該選擇那些能夠輕松從存儲位置讀寫數(shù)據(jù)的數(shù)據(jù)存儲技術(shù)。
• 易查詢性。功能強(qiáng)大的數(shù)據(jù)存儲技術(shù)能夠使您便捷迅速地搜索和選擇單個記錄或記錄集合。
• 同步數(shù)據(jù)存儲的能力。對于移動客戶端應(yīng)用程序，存儲在本地的脫機(jī)數(shù)據(jù)必須要與后端數(shù)據(jù)存儲保持同步。重新編寫同步機(jī)制不僅容易出錯，并且很耗時。因此選擇的數(shù)據(jù)存儲技術(shù)應(yīng)當(dāng)能夠支持對多個數(shù)據(jù)存儲的同步。