In this web content, the author discusses SQL query optimizers and their importance in database optimization. They mention their conversation with Mr. Chi about his project called “optd” at CMU, which is a query optimizer library. The author decides to launch a series of articles covering everything about query optimizers. They explain the definition and concept of a query optimizer and introduce the concept of Intermediate Representation (IR) in compilers. They discuss the components and structure of SQL AST and its connection to relational algebra. They also mention the importance of engineering practices in software development and provide examples of SQL IR design using Rust as the programming language. They conclude by introducing the concept of property derivation and its role in optimizing the IR.
https://xuanwo.io/2024/02-what-i-talk-about-when-i-talk-about-query-optimizer-part-1/