ECE356 Lecture Notes - Lecture 14: Linear Search, Binary Search Algorithm, Prentice Hall
26 Jul 2018
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Document Summary
Bu ering and caching are important in computing, as you surely know, since you have likely learned about it in multiple scenarios before now. The most recent probably related to caching in operating systems, where you may have modelled putting things into the l1 cache of a cpu. It is, nevertheless, applicable to databases as well. Where before we were concerned about whether we needed to fetch a page from memory into cache, now it is about whether we need to fetch a block from disk into memory. As discussed, a block number is used for a read or write operation, which we can translate into an address for the disk operation. Ideally, the block is found in the bu er, because that would be faster. If the requested block is not there, we must load the block from disk, a very slow operation. Bu ers are limited in size because memory is limited and it is expensive.
