render-postgres

# Render Managed PostgreSQL This skill covers **Managed Postgres on Render**: how to connect, what cannot change after creation, storage behavior, limits, HA, replicas, and safe deletion. Deep dives live under `references/`. ## When to Use Apply this skill when the user: - Configures **Postgres** for an app on Render (URLs, TLS, pooling) - Creates or changes a **database**, **plan**, **disk**, or **replicas** - Asks about **backups**, **PITR**, **exports**, or **deleting** a database - Hits **connection limits**, **SSL errors**, or **latency** between services and DB - Authors **Blueprint** `databases` / `readReplicas` or wires `fromDatabase` For deploy flows and Blueprint basics, see **render-deploy** and **render-blueprints**. For private networking between services, see **render-networking**. For env var patterns, see **render-env-vars**. ## Connection Patterns Render exposes **two connection URLs** for the same logical database: | URL | Use when | TLS | |-----|----------|-----| | **Internal** | App or service on Render in the **same region and workspace** | Not required (private network) | | **External** | Local development, CI, or tools outside Render | **Required** (TLS 1.2+) | **Always prefer the internal URL for Render-hosted apps** so traffic stays on Render’s network and avoids extra latency and public egress patterns. - **IP allow list** applies to **external** access only. Same-region Render services use the **internal** URL regardless of the allow list. - **External** clients must use TLS; misconfigured clients often show SSL handshake or `sslmode` errors. URL formats, Dashboard locations, Blueprint `fromDatabase`, pooling, and common mistakes: `references/connection-guide.md`. ## Creation and Setup - **Instance display name**: Can be changed later (where the Dashboard allows renaming the resource). - **Immutable after creation**: `databaseName`, database **user**, **region**, **PostgreSQL major version**. Plan these before create; changing them requires a new database and migration. - **Storage size**: **1 GB** or **multiples of 5 GB** when provisioning. Wire apps with Blueprint `fromDatabase` using `property: connectionString` (or `host`, `port`, `user`, `password`, `database` individually). See **render-blueprints**. ### Multiple logical databases You can run `CREATE DATABASE new_db;` in `psql` on the same instance. **Host, port, and credentials stay the same**; only the **database name in the URL path** changes (e.g. `.../myapp` vs `.../new_db`). ## Storage Management - **Autoscaling**: When disk use reaches roughly **~90%**, Render can grow storage by about **~50%**, rounded up to the **next 5 GB multiple**, up to **16 TB** max. - **Cannot shrink** disk after an increase. - **Cooldown**: After a storage increase, you **cannot increase again for 12 hours**. - **Over limit / unhealthy**: If disk is over the configured limit, the database can become **unhealthy**; Render may **suspend** it until resolved. Monitor disk and plan exports or cleanup before you hit hard limits. Backup and restore options: `references/backup-and-recovery.md`. ## Connection Limits Maximum connections depend on **instance RAM** (current-generation plans): | RAM | Max connections (typical) | |-----|---------------------------| | Under 8 GB | 100 | | 8 GB | 200 | | 16 GB | 300 | | 32 GB and above | 500 | **Legacy** database plans may have **lower** limits; confirm in the Dashboard or API for the specific plan. Render does **not** provide a built-in pooler; use **application-side pooling** (framework pools, PgBouncer, pgpool, etc.). Limits are **hard**—exhausting them causes connection errors. More detail: `references/connection-guide.md` and `references/performance-tuning.md`. ## High Availability **High availability (HA)** is available when: - Workspace is **Professional** or higher, **and** - Database plan is **Pro** or higher, **and** - **PostgreSQL 13+** **Instance type changes** cause **brief downtime**. With HA, downtime is typically **less** than **without HA** (often on the order of **minutes** without HA—exact duration depends on plan and operation). **One-way migration off legacy types**: After moving to current-generation instance types, you **cannot** move back to **legacy** instance types. ## Read Replicas - Up to **5 read replicas** per database. - In Blueprints, declare replicas under **`readReplicas`** as a **list of names**. - **CAUTION — declarative sync**: - An **empty** `readReplicas` list can **destroy all** existing replicas. - **Name mismatches** between the Blueprint and live replicas can **create** new replicas and **remove** replicas whose names are no longer listed. Always treat `readReplicas` as **authoritative** desired state, not additive-only. ## Useful MCP Commands Use the Render MCP tools (names may vary slightly by integration; align with your server’s tool list): | Goal | Tool / pattern | |------|----------------| | List databases | `list_postgres_instances` | | Instance details | `get_postgres` with `postgresId` | | Read-only SQL | `query_render_postgres` with `postgresId` and `sql` | | Connection load | `get_metrics` with `resourceId` (Postgres ID) and `metricTypes: ["active_connections"]` | `query_render_postgres` runs in a **read-only** transaction and opens a **new connection per query**—do not use it as a substitute for app pooling. Shorthand (same tools): `list_postgres_instances()`, `get_postgres(postgresId)`, `query_render_postgres(postgresId, sql)`, `get_metrics(resourceId, metricTypes: ["active_connections"])`. ## Deleting and Data Safety - **Backups and snapshots are not retained** after you **delete** the database. **Export first** (`pg_dump`, Dashboard restore workflow from existing backups, etc.). - Before destructive actions, confirm retention and recovery paths in `references/backup-and-recovery.md`. ## References | Document | Contents | |----------|----------| | `references/connection-guide.md` | Internal vs external URLs, SSL, allow list, Blueprint wiring, pooling, multi-database URLs, troubleshooting | | `references/backup-and-recovery.md` | Snapshots, PITR, `pg_dump` / `pg_restore`, restore flows, deletion, cross-region | | `references/performance-tuning.md` | `pg_stat_statements`, indexes, bloat, `EXPLAIN ANALYZE`, metrics, scaling | ## Related Skills - **render-deploy** — End-to-end deploy, services, and MCP/Dashboard flows - **render-blueprints** — `databases`, `fromDatabase`, `readReplicas`, immutable fields - **render-networking** — Private services, regions, and how traffic routes between resources - **render-env-vars** — Storing `DATABASE_URL` and secret wiring patterns