Implement database sharding for horizontal scalability. Use when scaling large databases, distributing data across multiple servers, or designing sharded architectures.
Implement horizontal data partitioning across multiple database servers. Covers sharding strategies, consistent hashing, shard key selection, and cross-shard querying patterns.
Minimal working example:
-- Define shard ranges
-- Shard 0: user_id 0-999999
-- Shard 1: user_id 1000000-1999999
-- Shard 2: user_id 2000000-2999999
CREATE TABLE users_shard_0 (
id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
user_id BIGINT NOT NULL,
email VARCHAR(255) NOT NULL,
created_at TIMESTAMP DEFAULT NOW(),
CONSTRAINT shard_0_range CHECK (user_id BETWEEN 0 AND 999999)
);
CREATE TABLE users_shard_1 (
id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
user_id BIGINT NOT NULL,
email VARCHAR(255) NOT NULL,
created_at TIMESTAMP DEFAULT NOW(),
CONSTRAINT shard_1_range CHECK (user_id BETWEEN 1000000 AND 1999999)
);
-- Function to determine shard
CREATE OR REPLACE FUNCTION get_shard_id(p_user_id BIGINT)
RETURNS INT AS $$
BEGIN
// ... (see reference guides for full implementation)
Detailed implementations in the references/ directory:
| Guide | Contents |
|---|---|
| Range-Based Sharding | Range-Based Sharding |
| Hash-Based Sharding | Hash-Based Sharding |
| Directory-Based Sharding | Directory-Based Sharding |