SQL is an industry-standard query language that works with relational databases. Unlike some earlier systems, queries are performed at the server and only the results are passed to a client. This resulted in the ability to work with large databases efficiently over a network.
This competency area includes the ability to demonstrate an understanding of query optimization, data modeling, Indexing, window functions, and pivots in SQL.
- Query Optimization - This competency includes the ability to demonstrate an understanding of the order of operations performed by the database server and can minimize time and space requirements.
- Data Modeling - This competency includes the ability to create effective UML diagrams of tables and relationships.
- Indexing, window functions, pivots - This competency includes understanding the role of indexes in query optimization, design indexes with appropriate keys to assist in query optimization, use window functions to create trailing averages, running sums, and can rotate data using PIVOT.