The SQL Query Roadtrip

The SQL Query Roadtrip

6 articles in this series •

Posts

  1. 1

    Overview

    • 11 min read

    Ever wonder what happens when you type SELECT * FROM users WHERE id = 42; and hit Enter? That simple query triggers a fascinating journey through PostgreSQL’s internals—a complex series of …

  2. 2

    Connections and Communication

    • 9 min read

    In the previous article , we explored the complete journey a SQL query takes through PostgreSQL—from parsing to execution. But before any of that can happen, your application needs to establish a …

  3. 3

    Parsing and Analysis

    • 12 min read

    In the previous article , we explored how PostgreSQL establishes connections and communicates using its wire protocol. Once your connection is established and the backend process is ready, you can …

  4. 4

    Query Rewriting

    • 11 min read

    In the previous article , we explored how PostgreSQL transforms SQL text into a validated Query tree through parsing and semantic analysis. By the end of that journey, PostgreSQL knows that your …

  5. 5

    The Query Planner

    • 19 min read

    In the previous article , we explored how PostgreSQL’s rewriter transforms queries—expanding views, applying security policies, and executing custom rules. By the end of that phase, your query …

  6. 6

    The Execution Engine

    • 15 min read

    In the previous article , we explored how PostgreSQL’s planner chooses the optimal execution strategy. The planner produces an abstract plan tree—nodes like “Sequential Scan,” …