Learn the definition of percentiles and why they are useful.
- [Instructor] One of the most common operations on data is sorting. For example, here is a list of 10 integer values. We can sort the list so that the smallest values are at the top and the largest values are at the bottom. This helps us see the progression of values from small to large. Now, this is a short list, so it's easy to review all of the values. But as lists of values get large, it can be more difficult to see patterns, like clusters of values. This is where bucketing or grouping can help.
Here is an example of assigning each value in the list to a decile or group of 10 buckets each of the same size. In this case, the size is 10, so the first decile is from zero to nine, the second from 10 to 19, and so on. In the next few videos, we'll work with SQL functions for bucketing data into percentiles, which are groups of 100 buckets of equal size.
- Loading data into PostgreSQL
- Variance and standard deviation
- Linear models, such as linear regression