# YugabyteDB — Distributed SQL That Is Fully PostgreSQL Compatible

> YugabyteDB is a distributed SQL database that reuses the PostgreSQL query layer while adding horizontal scale, multi-region replication, and resilience. It is Postgres you can shard across continents.

## Install

Save as a script file and run:

# YugabyteDB — Distributed PostgreSQL

## Quick Use
```bash
# Single-node Docker quickstart
docker run -d --name yb \
  -p 7000:7000 -p 9000:9000 -p 5433:5433 -p 9042:9042 \
  yugabytedb/yugabyte:latest bin/yugabyted start --daemon=false

# Connect via psql (port 5433) — Postgres wire protocol
psql -h localhost -p 5433 -U yugabyte
```

```sql
-- Exactly like Postgres
CREATE TABLE orders (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id BIGINT NOT NULL,
  amount DECIMAL(18,2),
  created TIMESTAMPTZ DEFAULT now()
);

INSERT INTO orders (user_id, amount) VALUES (1, 99.95), (2, 150.00);
SELECT * FROM orders WHERE amount > 100;
```

## Introduction
YugabyteDB takes the PostgreSQL query layer — indexing, extensions, JSONB, stored procedures, triggers — and puts it on top of a distributed storage engine (DocDB, a fork of RocksDB). The result is a database that feels exactly like Postgres to your ORM, but scales horizontally and survives zone/region failures.

With over 10,000 GitHub stars, YugabyteDB is used by General Motors, Kroger, Fidelity, and hundreds of companies that need Postgres semantics at cloud scale. It's a practical alternative to Spanner/Cosmos when you want PostgreSQL.

## What YugabyteDB Does
YugabyteDB runs two APIs: **YSQL** (PostgreSQL wire protocol, 99% syntax compatible) and **YCQL** (Cassandra wire protocol for semi-structured). Data is sharded across nodes via consistent hashing and replicated via Raft. Distributed ACID transactions use the two-phase commit protocol with hybrid logical clocks.

## Architecture Overview
```
Clients -> YSQL (Postgres wire) or YCQL (Cassandra wire)
              |
   [Query Layer — reuses Postgres PG code]
              |
   [DocDB Storage Engine]
     Sharded tablets (Raft-replicated)
     Based on RocksDB + Raft + Hybrid Logical Clocks
              |
   +----+----+----+----+
   |    |    |    |    |
 [Node A] [Node B] [Node C] ... (tablet peers)
              |
   [Coordinator master processes]
     Metadata, leader elections, load balancing
```

## Self-Hosting & Configuration
```sql
-- Geo-distributed table: user rows co-located with user's region
CREATE TABLE user_profiles (
  user_id BIGINT,
  region  TEXT,
  data    JSONB,
  PRIMARY KEY ((region), user_id)
) SPLIT INTO 3 TABLETS;

-- Tablespaces for placement policies
CREATE TABLESPACE us_east WITH (
  replica_placement = '{"num_replicas": 3, "placement_blocks": [
    {"cloud":"aws","region":"us-east-1","zone":"us-east-1a","min_num_replicas":1},
    {"cloud":"aws","region":"us-east-1","zone":"us-east-1b","min_num_replicas":1},
    {"cloud":"aws","region":"us-east-1","zone":"us-east-1c","min_num_replicas":1}
  ]}'
);

ALTER TABLE user_profiles SET TABLESPACE us_east;
```

## Key Features
- **PostgreSQL compatible** — YSQL runs real Postgres query code
- **Distributed transactions** — ACID across rows, tablets, regions
- **Horizontal scale** — add nodes, tablets rebalance automatically
- **Raft replication** — 3 or 5 replicas per tablet for HA
- **Multi-region** — synchronous or asynchronous replication modes
- **YCQL** — Cassandra wire protocol for key-value/wide-column use cases
- **Postgres extensions** — PostGIS, pgvector, pg_cron, etc. supported
- **YugabyteDB Aeon** — managed service on AWS/GCP/Azure

## Comparison with Similar Tools
| Feature | YugabyteDB | CockroachDB | Spanner | Aurora / Cloud SQL | TiDB |
|---|---|---|---|---|---|
| SQL dialect | PostgreSQL | Postgres-like | Own | PostgreSQL / MySQL | MySQL |
| Reuses PG code | Yes | No (own parser) | No | Yes (single region) | No |
| Horizontal scale | Yes | Yes | Yes | Read replicas only | Yes |
| Multi-region | Yes | Yes | Yes | Limited | Yes |
| Extensions | Many PG exts | Limited | None | Many | Limited |
| License | Apache-2.0 (core) | BUSL | Commercial (GCP) | Commercial | Apache-2.0 |
| Best For | Postgres at scale | Postgres-like at scale | GCP-only teams | Managed Postgres | MySQL at scale |

## FAQ
**Q: YugabyteDB vs CockroachDB?**
A: Both aim for distributed SQL. Yugabyte reuses actual Postgres code for YSQL — the richest Postgres compatibility. Cockroach has Postgres-like syntax but a custom parser. For apps that rely on Postgres extensions (pgvector, PostGIS), Yugabyte wins.

**Q: Can I just run Postgres with logical replication instead?**
A: Yes, if you're OK with one primary + read replicas and asynchronous replication. Yugabyte gives you active-active writes across nodes/regions with ACID guarantees — a different scale/resilience tier.

**Q: Is Yugabyte open source?**
A: Yes, Apache-2.0 core. Some advanced management features (xCluster, security) are in the Enterprise/Aeon tiers.

**Q: How is it for workloads with complex joins?**
A: Joins across tablets incur network shuffles. Co-locate related rows (hash partition by customer_id) to keep joins fast. Yugabyte's planner handles distributed joins, but design matters for multi-region deployments.

## Sources
- GitHub: https://github.com/yugabyte/yugabyte-db
- Docs: https://docs.yugabyte.com
- Company: Yugabyte
- License: Apache-2.0

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Source: https://tokrepo.com/en/workflows/09a16401-37d2-11f1-9bc6-00163e2b0d79
Author: Script Depot