Does it warrant extra cover?

是否保证了其他的保障呢？

Because each index incurs extra data updating overhead, the goal should be to create a small number of indexes to cover as many queries as possible.

因为索引会带来额外的数据更新开销，所以应该争取创建少量索引来覆盖尽可能多的查询。

The result is that many people head into retirement needing a little extra income to cover expenses and provide an adequate lifestyle or to maintain their pre-retirement lifestyle.

其结果就是许多人觉得退休后需要一些额外的收入来支付日常费用并且提供一个适当的生活方式或者维持他们退休前的生活方式。

The extra items sold must make enough profit at least to cover the cost of the additional time spent in selling them.

出售额外的商品获得的收益至少要能抵补花费的额外的销售成本。

He has asked his customers for an extra EUR 5 billion to cover his costs, but getting agreement is proving difficult.

他已经请求他的客户额外支付50亿欧元以包住他的成本，但取得一致显得很困难。