The data gets copied multiple times among the disk, kernel buffer, and user buffer before it is finally delivered to the application.

数据在被最终传入到应用程序前，在磁盘、内核缓冲区和用户缓冲区中被拷贝了多次。

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The compressed data is kept both on disk and memory and DB2 also compresses user data stored in log files, thereby reducing log file size.

被压缩的数据同时存放在磁盘上和内存中，DB2 还压缩存储在日志文件中的用户数据，以便减少日志文件大小。

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The I/O might involve reading data from a disk, or a database, or a web service, or even from a user.

I/O 可能涉及到从一个磁盘、一个 web 服务或甚至是一名用户读取数据。

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The flash memory in the Fusion Drive moves data and applications frequently accessed by the user to the flash memory and move less frequently used data to the hard disk drive as the flash memory becomes full.

FORBES: Will A Fusion Drive Approach Become Widespread in Computers?

Perhaps the biggest gain may be in dual storage computers where a flash memory device is used for storing operating systems, software and frequently accessed content (and maybe even for write caching) while a hard disk drive provides much less expensive mass storage of user data.

FORBES: New Flash Memory Devices Will Lead to 128 GB Consumer Products and More Flash in Computer Systems