Why aren't in memory databases commonly used?

为什么不在内存数据库常用的？

youdao

The virtual database coordinates the execution of the queries on the physical databases and post-processes the results of the individual query in memory to prepare a consolidated result.

此虚拟数据库会协调这些查询在物理数据库上的执行，并会在内存内置后处理各个查询的结果用以准备一个合并结果。

youdao

He adds that "the fastest databases have direct access to a piece of information, in memory, if possible."

他还补充道：“最快的数据库能够尽可能直接从内存中访问信息块。”

youdao

Rather than memories that have to go to a specific address and step and fetch it, they can address databases in memory through similar content methods.

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As the name suggests, databases are held in memory, not on disk, which significantly reduces the read time.

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According to those familiar with the technology, the initial, primary use of 64-bit computing will be driving large, enterprise-level applications that require more than 4GB of memory -- applications most commonly found in large databases.

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