Inside SQLite’s Frontend: BETWEEN, OR, LIKE, and GLOB Optimizations

Hello, I'm Maneshwar. I'm building git-lrc, an AI code reviewer that runs on every commit. It is free, unlimited, and source-available on Github. Star Us to help devs discover the project. Do give it a try and share your feedback for improving the product. In the previous part, you saw how SQLite breaks the WHERE clause into terms and uses strict rules to decide whether indexes can be applied. Now we go deeper into specific operators that appear frequently in real queries and how SQLite optimizes them. These operators may look simple at the SQL level, but internally SQLite often rewrites them or applies special strategies to make them efficient. How SQLite Handles the BETWEEN Clause The BETWEEN clause is commonly used for range queries. For example: SELECT * FROM users WHERE age BETWEEN 18 AND 30 ; SQLite does not treat this as a special standalone operation. Instead, it rewrites it internally into two conditions: age >= 18 AND age <= 30 This transformation introduces two virtual terms