# Amazon RDS

Canonical: https://inetgeek.com/databases/amazon-rds/

AWS managed relational database service running PostgreSQL, MySQL, MariaDB, Oracle, SQL Server and Db2 on provisioned DB instances.

## Who it suits

Teams already inside AWS, where the database sitting in the same VPC as everything else is worth more than any single feature on this page. Six engines, up to 35 days of point-in-time recovery, and read replicas you create and delete yourself.

Consider something else if You want a database per pull request. RDS documents no branching, and replicas are manual — AWS states outright that it does not autoscale them.

## What the documentation says

### Execution

- Managed connection pooling: Supported ([source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/rds-proxy.html), read 2026-09-09)

### Data

- Engine: PostgreSQL, alongside MySQL, MariaDB, Oracle, SQL Server and Db2. Each engine is a separate RDS product with its own version list and its own feature support, so a capability documented for one is not a capability of RDS as a whole. ([source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html), read 2026-09-09)
- Connection limit: Not a fixed number: RDS for PostgreSQL sets max_connections by formula from the instance's memory — LEAST({DBInstanceClassMemory/9531392}, 5000) — so a bigger instance class gets more connections and the ceiling is 5,000 however large it is. The parameter can be set by hand anywhere from 6 to 262,143, which is a limit on what you may configure rather than what an instance will serve. Other engines use different divisors: MySQL is memory/12582880 with no cap. ([source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_Limits.html), read 2026-09-09)
- Point-in-time recovery: Any point inside the configured backup retention period, so up to 35 days. Transaction logs are uploaded to S3 every five minutes, which is what bounds how close to now the latest restorable time can be. ([source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_PIT.html), read 2026-09-09)
- Read replicas: Supported — 15 per primary, raisable on request ([source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_Limits.html), read 2026-09-09)
- Backup retention: Between 0 and 35 days, set per DB instance; 0 disables automated backups entirely. The default depends on how the instance was created — one day via the API or CLI, seven days via the console — so there is no single default to quote. Multi-AZ DB clusters cannot be set below 1 day. ([source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithAutomatedBackups.BackupRetention.html), read 2026-09-09)

## Compared with

- [Amazon RDS vs Amazon Aurora](https://inetgeek.com/compare/amazon-rds-vs-amazon-aurora/)