index.md

Prequel

Prequel is a query engine capable of querying any data source using common SQL syntax.

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This project was originally inspired by Apache Data Fusion. The intent of this project is to demonstrate how query engines work while bringing a user-friendly SQL query engine to the .NET community

The code in this project uses the SqlParser C# SQL grammar parser project to parse SQL statements and, in turn, transform the statements into a series of executable read operations against any number of backing data sources.

This project’s documentation outlines every step involved in building a generic query engine.

Table of Contents

1. Data Types
2. Data Sources
3. Logical Plans
4. Physical Plans
5. Query Planning
6. Query Optimization
7. Query Execution
8. Async Enumeration
9. Rows vs. Columns
10. SQL Dialect