SQL CUBE+GROUP BY for Subtotals We all have used GROUP BY, but do you know CUBE? For example, if I have a table of user Travis Tang Dec 13, 2022
Python Vaex: Using an Out-of-Core Approach to Process Large Datasets Faster big-data analysis workflows with Vaex Travis Tang Dec 10, 2022 5 min read
SQL Get subtotals with ROLLUP+GROUP BY ππππππ generates extra rows that represent the subtotals. For exampleβ¦ To get the sum of spending of each user, you typically Travis Tang Dec 6, 2022 1 min read
SQL CROSS JOIN for all combinations It is the cartesian products of both tables, if you're a math nerd. π Syntax: ππ΄π»π΄π²π * π΅ππΎπΌ πππππ_π· π²ππΎππ πΉπΎπΈπ½ πππππ_πΈ Note that there is no need Travis Tang Dec 3, 2022 1 min read
SQL KNN with SQL Here's a quick implementation of supervised learning, the k-nearest neighbor (KNN) classification algorithm. To get you up to speed, the Travis Tang Nov 29, 2022 1 min read
Career 3 On-the-Job Tips for DataΒ Analysts Simple steps for better analytics Travis Tang Nov 2, 2022 5 min read