# restrict_nonsystem_relation_kind

> restrict_nonsystem_relation_kind is the PostgreSQL setting that prohibits access to non-system relations of specified kinds.
---

> [!NOTE]
> **Fact — official short description:** “Prohibits access to non-system relations of specified kinds.”

## Identity {#identity}

| Field | Value | Meaning |
| --- | --- | --- |
| Type | `string` | Upstream pg_settings type |
| Context | `user` | Settable by an ordinary user |
| Unit | — | Raw unit |
| Range | — | Raw limits in the last observed version |
| Enum values | — | — for non-enum types |
| Category | Client Connection Defaults / Statement Behavior | Upstream classification |
| Latest boot value | `""` | empty string |
{.fields meta="-"}

## Lifecycle {#lifecycle}

| Fact | Value |
| --- | --- |
| First observed | PG12 |
| Present in | PG12–19 Beta 3 |
| Removed in | No |
| Introduction commit | [`79c7a7e29695`](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=79c7a7e29695a32fef2e65682be224b8d61ec972) — Restrict accesses to non-system views and foreign tables during pg_dump. |
| Commit date | 2024-08-05 |
| Discussion | — |

## Default history {#default-history}

| Versions | Raw `boot_val` | Unit | Human value |
| --- | --- | --- | --- |
| PG12–19 Beta 3 | `""` | — | empty string |
{.full-width caption="Measured PG9.0–19 Beta 3 boot defaults"}

## How it works {#mechanism}

restrict_nonsystem_relation_kind prohibits access to non-system relations of specified kinds. The supported kinds are view and foreign-table; PostgreSQL uses the restriction as a safety boundary for specialized sessions, not as general SQL authorization.

restrict_nonsystem_relation_kind is a USER-context setting. An authorized role can change it for a session, while ALTER ROLE or ALTER DATABASE can establish a default for future sessions.

Because session state can survive in pooled connections, role defaults, SET privilege, RESET behavior, and application checkout hooks are part of the control's effective boundary.

## Tuning advice {#tuning-advice}

> [!TIP]
> **Advice.** These are workload-specific starting points and must be validated with measurements.

| Workload | Guidance |
| --- | --- |
| OLTP | Do not tune restrict_nonsystem_relation_kind as a general security policy. Leave it empty unless a PostgreSQL subsystem or tightly scoped maintenance workflow explicitly requires the restriction. |
| OLAP | Do not use it to sandbox arbitrary analytical users; enforce access with privileges, schemas, and row-level policies. |
| Small nodes | Keep the default empty. Enabling relation-kind bans has no capacity benefit and can break ordinary queries unexpectedly. |
{.full-width}

## Pigsty {#pigsty}

Values use the fixed 8-vCPU, 32-GiB, 100-GiB SSD fixture and render the current Pigsty templates for PG19 Beta 3; this does not assert current Pigsty support for that historical or beta release.

| Template | Effective value | Versus upstream boot | Source expression |
| --- | --- | --- | --- |
| OLTP | Unmodified | — | — |
| OLAP | Unmodified | — | — |
| CRIT | Unmodified | — | — |
| TINY | Unmodified | — | — |
{.full-width}

> [!CAUTION]
> **Advice — pending human review.** Fact from the current Pigsty template projection: OLTP: PG12–19 Beta 3 unmodified; OLAP: PG12–19 Beta 3 unmodified; CRIT: PG12–19 Beta 3 unmodified; TINY: PG12–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

## Common pitfalls {#common-pitfalls}

- Changing restrict_nonsystem_relation_kind in one session and assuming role defaults, database defaults, or other pooled sessions changed with it.
- Granting broad SET rights to a control that can change correctness, policy enforcement, or name resolution.
- Failing to reset a security-sensitive session value before a pooled connection is reused by another request.
- Changing restrict_nonsystem_relation_kind globally without a rollback plan and a client or operational compatibility test.

## Related parameters {#related-parameters}

[`search_path`](/parameters/search-path/) · [`row_security`](/parameters/row-security/) · [`session_replication_role`](/parameters/session-replication-role/) · [`event_triggers`](/parameters/event-triggers/) · [`createrole_self_grant`](/parameters/createrole-self-grant/)

## References {#references}

- [PostgreSQL 19 Beta 3 — restrict_nonsystem_relation_kind](https://www.postgresql.org/docs/19/runtime-config-client.html#GUC-RESTRICT-NONSYSTEM-RELATION-KIND)
- [PostgreSQL 19 release notes](https://www.postgresql.org/docs/19/release-19.html)
- [Machine-readable GUC export](/data/guc.jsonl)