rds

1# AWS RDS
2 
3Amazon Relational Database Service (RDS) provides managed relational databases including MySQL, PostgreSQL, MariaDB, Oracle, SQL Server, and Aurora. RDS handles provisioning, patching, backups, and failover.
4 
5## Table of Contents
6 
7- [Core Concepts](#core-concepts)
8- [Common Patterns](#common-patterns)
9- [CLI Reference](#cli-reference)
10- [Best Practices](#best-practices)
11- [Troubleshooting](#troubleshooting)
12- [References](#references)
13 
14## Core Concepts
15 
16### DB Instance Classes
17 
18| Category | Example | Use Case |
19|----------|---------|----------|
20| Standard | db.m6g.large | General purpose |
21| Memory Optimized | db.r6g.large | High memory workloads |
22| Burstable | db.t3.medium | Variable workloads, dev/test |
23 
24### Storage Types
25 
26| Type | IOPS | Use Case |
27|------|------|----------|
28| gp3 | 3,000-16,000 | Most workloads |
29| io1/io2 | Up to 256,000 | High-performance OLTP |
30| magnetic | N/A | Legacy, avoid |
31 
32### Multi-AZ Deployments
33 
34- **Multi-AZ Instance**: Synchronous standby in different AZ
35- **Multi-AZ Cluster**: One writer, two reader instances (Aurora-like)
36 
37### Read Replicas
38 
39Asynchronous copies for read scaling. Can be cross-region.
40 
41## Common Patterns
42 
43### Create a PostgreSQL Instance
44 
45**AWS CLI:**
46 
47```bash
48# Create DB subnet group
49aws rds create-db-subnet-group \
50  --db-subnet-group-name my-db-subnet-group \
51  --db-subnet-group-description "Private subnets for RDS" \
52  --subnet-ids subnet-12345678 subnet-87654321
53…