From the course: SQL for Statistics Essential Training

Unlock the full course today

Join today to access over 22,600 courses taught by industry experts or purchase this course individually.

Summary of correlations

Summary of correlations - PostgreSQL Tutorial

From the course: SQL for Statistics Essential Training

Start my 1-month free trial

Summary of correlations

“

- [Narrator] Relational databases are designed so that the order of rows usually does not matter. We can do things like ordering rows when we need to, but sometimes we need to know more about the relation between values within a row and values across rows. We've seen three functions that can help what these kinds of relations. The correlation function measures how two variables change with respect to each other. The row number function allows us to provide a rank order to a row but in a way that does not depend on the sort order of the query. The mode function tells us about the most frequently occurring value in a group of rows. All three of these functions are useful for helping us understand how data within a row and across a row relate to each other.

Contents