Windowing functions in recursive CTE

July 13, 2019March 23, 2019 ~ afish ~ Leave a comment

Today we will see an interesting case of incompatibility between MS SQL Server 2017 and PostgreSQL 9.6 (and different versions as well). Let’s start with this code: We emulate a recursive CTE. We have two columns in source dataset, we want to sum first column for rows partitioned by second column. This gives a very … Continue reading Windowing functions in recursive CTE

Machine Learning Part 4 — Linear regression in T-SQL

November 10, 2018February 12, 2019 ~ afish ~ 2 Comments

This is the fourth part of the ML series. For your convenience you can find other parts in the table of contents in Part 1 – Linear regression in MXNet This time we are going to implement linear regression as a function. This gives us a little more flexibility in terms of debugging the code … Continue reading Machine Learning Part 4 — Linear regression in T-SQL

Machine Learning Part 2 — Linear regression in SQL

October 27, 2018August 1, 2018 ~ afish ~ 2 Comments

This is the second part of the ML series. For your convenience you can find other parts in the table of contents in Part 1 – Linear regression in MXNet Image that you have only a data warehouse with SQL capabilities to train and evaluate your models. Last time we ran Python code to calculate … Continue reading Machine Learning Part 2 — Linear regression in SQL