Glacier.Sql 1.0.0

Glacier.Sql

Glacier.Sql is a high-performance C# SQL query execution engine built directly on top of the Glacier.Polaris columnar, memory-efficient Arrow-backed DataFrame engine. It translates T-SQL queries into optimized Polaris LazyFrame expression pipelines, enabling low-overhead SQL access to columnar files on disk.

Features

• T-SQL Parser: A custom Pratt/recursive-descent tokenizer and parser implementing standard SELECT, INSERT, UPDATE, DELETE, CREATE, ALTER, and DROP statements.
• Transactional Storage: SQL-native transactions (BEGIN TRANSACTION, COMMIT, ROLLBACK) with crash-recovery mechanisms via shadowed table file logging.
• Native Triggers: Persistent, automated SQL-native triggers (AFTER and INSTEAD OF for INSERT, UPDATE, and DELETE events) with virtual inserted and deleted context resolution.
• Relational View Engine: Fully persisted relational view definitions in the catalog, recursively inlined into query execution plans.
• Correlated Subqueries: Support for scalar subqueries, list membership (IN), and correlated/uncorrelated existential qualifiers (EXISTS / NOT EXISTS) mapped to optimized Semi/Anti relational joins.
• Schema Alterations: Schema modifications (ALTER TABLE ADD/DROP COLUMN) with automatic Arrow IPC file rewrites and null-padding.
• Data Integrity Constraints: Robust column-level constraints including PRIMARY KEY, UNIQUE, NOT NULL, and CHECK expressions with transaction rollbacks on violation.
• Concurrency & Locking: Async-friendly, thread-independent reader-writer locking mechanism to ensure serializable write isolation and non-blocking shared reads.
• Information Schema: Transient system metadata querying via INFORMATION_SCHEMA.TABLES and INFORMATION_SCHEMA.COLUMNS.

Project Structure

Glacier.Sql/
│
├── Glacier.Sql.slnx               # Visual Studio Solution model
│
├── src/
│   ├── Glacier.Sql/               # Main engine assembly
│   │   ├── Catalog/               # Metadata catalog & async-friendly table locking
│   │   ├── Engine/                # Query compilation (Planner), Execution handlers & SQL Engine
│   │   ├── Parser/                # Lexer, AST Nodes, Pratt Statement/Expression Parsers
│   │   └── Storage/               # Arrow IPC reading and writing wrappers
│   │
│   └── Glacier.Sql.Host/          # Stdio-based JSON-RPC MCP Server host
│
├── tests/
│   └── Glacier.Sql.Tests/         # Extensively covered XUnit test suite
│
└── MANUAL.md                      # Comprehensive User & Developer SQL reference manual

Getting Started

Prerequisites

• .NET 10.0 SDK

Build the Solution

Run the following command in the solution root directory to compile:

dotnet build

Run Tests

To execute the test suite validating transactions, triggers, view inlining, subqueries, concurrency locking, and constraint enforcement:

dotnet test

For more detailed information on syntax, design patterns, and internal architecture, see MANUAL.md.