Blake Miner's Blog

This blog post will cover the varying levels of data caching and data persistence provided by various operating systems and database systems. Cache  - A device placed in front of another storage device that is used for temporary storage of data.  The use of a hardware cache is often transparent to the end user and is generally smaller, faster, and less persistent than the backed storage device.  Rather than reading/writing from/to a slower storage device (i.e. a hard disk), we read/write from/to the cache (i.e. RAM, NVRAM, etc.). Reading from a cache is simple.  If the datum we requested is in the cache, we simply read it from the cache.  If not, we need to retrieve the datum from the storage device and place it into the cache (often a much slower operation). There are different policies when we write to the cache, though... Write-Through Cache Policy  - When using this policy, writing over the cache also writes over the data on the backed storage device... synchronously and si