Preparing to Make Resources Available Offline - Page 2

Pros and Cons of Automatic Caching

You must also take care to specify the method of making data available offline that makes the most sense for your organization. Any time you make a file or folder available for offline use, you're presented with three choices for how to do so: Automatic Caching, Manual Caching, or Automatic Caching For Programs. Each of these choices has its own advantages and disadvantages. You must carefully consider these advantages and disadvantages to determine which type of caching is most appropriate for each resource.

Automatic caching is the simplest type of caching. Any time a user opens a file that's been designated as available for offline use, the file is automatically added to the user's cache. Although this method sounds great, it has some drawbacks. For starters, automatic caching isn't good for people who tend to use a lot of different filesregardless of the file size, caches tend to fill up over time.

To illustrate why this is a problem, consider what would happen if you have a file that you need to use offline. You open the file to cache it. Now, suppose you work with several other files over the course of the day that are also designated as being available offline. As you work with these files, they are also added to the cache. Eventually, the cache may fill up. Obviously, when this happens, something has to go. To decide what stays and what goes, Windows uses an algorithm that looks at which files are used most frequently and which files were opened most recently. If the file you really needed hasn't been opened recently and you haven't done much work with it yet, there's a good chance that it could be discarded from the cache, meaning that it won't be available offline when you need it.

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The other reason automatic caching isn't good for large numbers of files is that it only caches files that you've opened. Suppose you need offline access to an entire folder or group of folders. In such a situation, you'll have to open every file in the entire folder structure to make the structure available offline, and then hope that you didn't fill up the cache along the way.

As you can see, automatic caching is best suited to users who need constant offline access to a few select documents. Later in this series, I'll explain how such users can avoid accidentally filling their caches with unwanted documents by caching only the documents that they specifically need. In the next article in the series, Part 2, I'll explain the pros and cons of manual caching and automatic caching for programs. //

Brien M. Posey is an MCSE who works as a freelance writer. His past experience includes working as the director of information systems for a national chain of health care facilities and as a network engineer for the Department of Defense. Because of the extremely high volume of e-mail that Brien receives, it's impossible for him to respond to every message, although he does read them all.