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