31 Aug 2017 Aldo Zelen Common SQL Window Functions: Positional Functions Positional SQL window functions deal with data's location in the set. In this post, we explain LEAD, LAG, and other positional functions. SQL window functions allow us to aggregate data while still using individual row values. We've already dealt with ranking functions and the use of partitions. In this post, we'll examine positional window functions, which are extremely helpful in reporting and summarizing data. Specifically, we'll look at LAG, LEAD, FIRST_VALUE and LAST_VALUE. Read more 7 Aug 2017 Aldo Zelen SQL Window Functions: Partitions and Ranking Functions You’ve started your mastery of SQL window functions by learning RANK, NTILE, and other basic functions. In this article, we will explain how to use SQL partitions with ranking functions. Mastering SQL window functions (AKA analytical functions) is a bumpy road, but it helps to break the journey into logical stages that build on each other. In the previous Common SQL Functions article, you learned about the various rank functions, which are the most basic form of window functions. Read more 17 Jul 2017 Aldo Zelen How to Use Rank Functions in SQL Want to learn how to use ranking functions in SQL? They are a good choice if you want to start using SQL window functions! Learning about SQL window functions usually comes after you’ve built a foundation in the language, but these powerful functions take your skills up a level. As you master them, you’ll find better ways to solve query problems. When used for business intelligence applications, SQL queries combine data retrieval and advanced computations. Read more 11 Jul 2017 Dejan Sarka Statistics in SQL: Measuring Spread of Distribution Besides knowing the centers of a distribution in your data, you need to know how varied the observations are. In this article, we’ll explain how to find the spread of a distribution in SQL. Are you dealing with a very uniform or a very spread population? To really understand what the numbers are saying, you must know the answer to this question. In the second part of this series, we discussed how to calculate centers of distribution. Read more