EmbeddingGemma 2: an open, lightweight multimodal embedding model
deepmind.google·6d ago
AI Engineering
Lobsters·Aug 13·5 min read
Write a SQL Optimizer using Egg (2023)
TL;DR
A small SQL optimizer was built using the Egg framework in Rust, implementing classic optimization techniques to enhance query efficiency. It supports both rule-based and cost-based optimization, demonstrating its capability with actual TPC-H queries.
✦ Why It Matters
Explore the SQL Optimizer Labs to implement similar optimization techniques in your projects today.
Key Takeaways
- Implement classic optimization techniques like constant folding.
- Utilize the Egg framework for custom SQL optimizers.
- Explore rule-based and cost-based optimization strategies.
- Analyze query plans to improve execution efficiency.
How It Works
The optimizer uses an e-graph data structure to represent expressions and their equivalences, allowing for efficient rewriting and optimization. By defining SQL expressions as algebraic data types in Rust, developers can create transformation rules that simplify and optimize queries.
The Egg framework's ability to dynamically manage equivalence classes enables the optimizer to explore multiple equivalent forms of an expression, ultimately selecting the most efficient one based on defined cost functions.