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This is the second course in our Specialization in Teradata and Data Analysis. In the first course, we set up the concepts, principles, and practical basics to install software, load data, and design a logical and physical data model. In this second course, we'll improve our techniques for data analysis, with an eye on efficiency and storage for your real-world applications on the job. In Module 1, we鈥檒l grow your SQL Toolkit with multi-table, aggregate functions like SUM, AVG, MAX and COUNT. We鈥檒l also expand your concept of primary and foreign keys, so you can make your first JOIN commands in SQL and define relationships between tables. Our second module is focused on SQL subqueries. We鈥檒l start with single-row subqueries, comparing them to JOIN commands. Then we鈥檒l examine multiple-row subqueries, which allow you to compare a value against multiple values returned from a subquery. In Module 3, we鈥檒l examine SQL Techniques. We鈥檒l recognize use cases and strategies to use windowed functions in SQL. We鈥檒l define the structure of hierarchical queries in SQL. And we鈥檒l identify for using indexes, so we can optimize our tables for data retrieval.