Overview

DropDB is a fully-featured database written in Go, designed as an educational project inspired by Edward Sciore's Database Design and Implementation. The project extends beyond the book's implementation with enhanced features, optimizations, and additional capabilities.

The goal is to implement a fairly feature-complete database while exploring database internals, including storage management, query processing, transaction handling, and optimization techniques.

Core Features

Implemented

• Disk and File Management

  • Efficient storage and retrieval with optimized disk layout
  • Byte alignment optimization for improved performance

• Memory Management

  • Intelligent memory allocation for data and metadata
  • Statistics tracking for query planning optimization

• Transaction Management

  • ACID compliance with atomicity and durability
  • Robust transaction processing and recovery

• Record and Metadata Management

  • Efficient record access and updates
  • Comprehensive schema and table definition management

• Query Processing

  • SQL parsing and execution
  • Materialization and sorting capabilities
  • Support for complex queries with multiple clauses

• Indexing

  • B-tree index implementation
  • Performance optimization for data retrieval

In Development

• Buffer Management

  • Smart buffer pool management
  • I/O optimization strategies

• Query Optimization

  • Cost-based query planning
  • Execution plan optimization

Data Types and Operations

Supported Types

• int, short, long
• string
• bool
• date

Query Capabilities

• Comparison Operators: =, !=, >, <, >=, <=
• Aggregation Functions:
  • COUNT, SUM, AVG, MIN, MAX
  • Note: AVG and SUM results use integer casting due to current floating-point limitations
  • Precision issues may occur with 64-bit integers on 32-bit machines

Query Features

• Aggregations
• GROUP BY clauses
• HAVING clauses
• ORDER BY (currently ascending only)

SQL Support

Supported Commands

SELECT

-- Basic query with conditions
SELECT name
FROM users
WHERE id = 1

-- Join query
SELECT name, dept_name
FROM users,
     departments
WHERE users_dept_id = dept_id

-- Aggregation with grouping
SELECT dept, avg(salary)
FROM employees
GROUP BY dept

-- Complex query
SELECT category, date, sum (amount)
FROM orders
WHERE amount > 500
GROUP BY category, date
HAVING sum (amount) > 2000
ORDER BY total asc

Data Definition

• CREATE TABLE - Define new tables with specified fields and types
• CREATE VIEW - Create stored queries
• CREATE INDEX - Build indexes for performance optimization

Data Manipulation

• INSERT - Add new records
• UPDATE - Modify existing records
• DELETE - Remove records based on conditions

Project Goals

DropDB serves as both a learning platform and a practical implementation of database concepts. While primarily developed for educational purposes, it aims to provide real-world database functionality and performance.

Contributing

Contributions are welcome! Feel free to:

• Open issues for bugs or feature requests
• Submit pull requests for improvements
• Share feedback on implementation approaches

The project particularly welcomes contributions in areas like buffer management and query optimization.