This is necessary to isolate the relational layer from the object layer, but this convenience comes at the cost of performance.

这对于将关系层与对象层分离是必需的，但这种便利是以牺牲性能为代价获得的。

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Moving up a layer has a cost in terms of adopting certain practices in development, build, and operations, but also has benefits.

就开发、构建和运营时所采用的具体实践来说，升级到上一层会有成本，但也会有好处。

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The inclusion of such a layer involves an additional up front development cost.

包含这样一个层涉及了额外的早期开发成本。

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Many people think employers should not be in the business of providing health insurance coverage anyway because of the added layer of complexity and cost, so this might be a good thing.

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Each layer of distribution adds to the cost of goods thus eating into their already razor-thin margins, since all consumer goods sold in India have an MSRP which is the final price a customer is willing to pay.

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That extra layer of regulation will come at a cost for many banks, particularly small ones.

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