>>6
The nature of the data being processed informs which specific algorithms you design for your system. Subject to the requirements of the system, you'll need to figure out how to structure the data so that your algorithms can process a small subset of data with respect to the total dataset that your system will hold.
Let's consider the example of a business that is tracking a warehouse of items. In this scenario, it's common for the system to maintain data for hundreds of thousands of individual items. So your system would have to maintain item descriptions, names, codes, unit quantites, location, etc. Merely deciding on structure to store the data of the items is certainly going to affect the algorithms you're going to use to search for specific items. There are going to be algorithms that are suitable for your dataset-data structure, and there are going to be algorithms that are less suitable.