# gss_accept_delegation

> gss_accept_delegation is the PostgreSQL setting that defines whether GSSAPI delegation should be accepted from the client.
---

> [!NOTE]
> **Fact — official short description:** “Sets whether GSSAPI delegation should be accepted from the client.”

## Identity {#identity}

| Field | Value | Meaning |
| --- | --- | --- |
| Type | `bool` | Upstream pg_settings type |
| Context | `sighup` | Takes effect after configuration reload |
| Unit | — | Raw unit |
| Range | — | Raw limits in the last observed version |
| Enum values | — | — for non-enum types |
| Category | Connections and Authentication / Authentication | Upstream classification |
| Latest boot value | `off` | off |
{.fields meta="-"}

## Lifecycle {#lifecycle}

| Fact | Value |
| --- | --- |
| First observed | PG16 |
| Present in | PG16–19 Beta 3 |
| Removed in | No |
| Introduction commit | [`9c0a0e2ed92a`](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=9c0a0e2ed92a1a94ec30d36f8ea1ab12c928292b) — rename "gss_accept_deleg" to "gss_accept_delegation". |
| Commit date | 2023-05-20 |
| Discussion | [thread 1](https://postgr.es/m/ZGdnEsGtNj7+fZoa@momjian.us) |

## Default history {#default-history}

| Versions | Raw `boot_val` | Unit | Human value |
| --- | --- | --- | --- |
| PG16–19 Beta 3 | `off` | — | off |
{.full-width caption="Measured PG9.0–19 Beta 3 boot defaults"}

## How it works {#mechanism}

gss_accept_delegation sets whether GSSAPI delegation should be accepted from the client. Accepting delegated credentials lets server-side code act with the client's GSS identity, so it expands trust beyond ordinary authentication.

gss_accept_delegation is a SIGHUP-context setting: a configuration reload activates the new server value without a restart; subsequent operations that consult it use the refreshed value.

The final authentication path combines this setting with pg_hba.conf, role attributes, credential material, client capabilities, and sometimes operating-system identity services.

## Tuning advice {#tuning-advice}

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

| Workload | Guidance |
| --- | --- |
| OLTP | Set gss_accept_delegation from the authentication architecture and security policy, not workload throughput. Test every driver, identity mapping, failover path, and credential-rotation procedure. |
| OLAP | Apply the same security baseline to analytical access; isolate any legacy client exception to a dedicated role and a dated migration plan. |
| Small nodes | Prefer the current secure default for gss_accept_delegation. Avoid weakening authentication to save marginal CPU on a small node; reduce connection churn with pooling instead. |
{.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: PG16–19 Beta 3 unmodified; OLAP: PG16–19 Beta 3 unmodified; CRIT: PG16–19 Beta 3 unmodified; TINY: PG16–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

## Common pitfalls {#common-pitfalls}

- Editing gss_accept_delegation without reloading configuration and verifying the effective value and subsequent behavior.
- Changing one authentication setting without testing pg_hba.conf ordering, existing secrets, mappings, and every client library.
- Weakening identity policy to solve connection churn or CPU cost that should be addressed with pooling and capacity planning.
- Changing gss_accept_delegation globally without a rollback plan and a client or operational compatibility test.

## Related parameters {#related-parameters}

[`password_encryption`](/parameters/password-encryption/) · [`scram_iterations`](/parameters/scram-iterations/) · [`md5_password_warnings`](/parameters/md5-password-warnings/) · [`authentication_timeout`](/parameters/authentication-timeout/) · [`oauth_validator_libraries`](/parameters/oauth-validator-libraries/) · [`krb_server_keyfile`](/parameters/krb-server-keyfile/)

## References {#references}

- [PostgreSQL 19 Beta 3 — gss_accept_delegation](https://www.postgresql.org/docs/19/runtime-config-connection.html#GUC-GSS-ACCEPT-DELEGATION)
- [PostgreSQL 19 release notes](https://www.postgresql.org/docs/19/release-19.html)
- [Machine-readable GUC export](/data/guc.jsonl)