# client_min_messages

> client_min_messages is the PostgreSQL setting that defines the message levels that are sent to the client.
---

> [!NOTE]
> **Fact — official short description:** “Sets the message levels that are sent to the client.”

## Identity {#identity}

| Field | Value | Meaning |
| --- | --- | --- |
| Type | `enum` | Upstream pg_settings type |
| Context | `user` | Settable by an ordinary user |
| Unit | — | Raw unit |
| Range | — | Raw limits in the last observed version |
| Enum values | `debug5`, `debug4`, `debug3`, `debug2`, `debug1`, `log`, `notice`, `warning`, `error` | — for non-enum types |
| Category | Client Connection Defaults / Statement Behavior | Upstream classification |
| Latest boot value | `notice` | notice |
{.fields meta="-"}

## Lifecycle {#lifecycle}

| Fact | Value |
| --- | --- |
| First observed | PG9.0 (research boundary) |
| Present in | PG9.0–19 Beta 3 |
| Removed in | No |
| Introduction commit | Not asserted: predates the PG9.0 research boundary |
| Commit date | — |
| Discussion | — |

## Default history {#default-history}

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

## How it works {#mechanism}

client_min_messages sets the message levels that are sent to the client. Each level includes all the levels that follow it. The later the level, the fewer messages are sent. The threshold governs messages returned to the client, not messages written to the server log, and INFO is delivered regardless of the chosen threshold.

client_min_messages 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.

It affects the client protocol's diagnostic stream, while log_min_messages and log_min_error_statement independently control server-side records; INFO remains a special always-sent level.

## Tuning advice {#tuning-advice}

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

| Workload | Guidance |
| --- | --- |
| OLTP | Set client_min_messages from the application's diagnostic contract. Keep actionable warnings visible and change the threshold per role or session rather than muting an entire cluster. |
| OLAP | Analytical and interactive users may prefer NOTICE output, but batch pipelines should explicitly choose the messages they can parse without treating notices as result rows. |
| Small nodes | Leave the default NOTICE unless client chatter is measured as a problem; suppressing messages does not materially increase server capacity. |
{.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: PG9.0–19 Beta 3 unmodified; OLAP: PG9.0–19 Beta 3 unmodified; CRIT: PG9.0–19 Beta 3 unmodified; TINY: PG9.0–19 Beta 3 unmodified. No Pigsty-specific rationale is inferred from an absent override.

## Common pitfalls {#common-pitfalls}

- Changing client_min_messages in one session and assuming role defaults, database defaults, or other pooled sessions changed with it.
- Copying severity expectations from log_min_messages even though the client ordering treats LOG differently and always sends INFO.
- Suppressing warnings globally and hiding deprecations or operational guidance that applications should surface.
- Changing client_min_messages globally without a rollback plan and a client or operational compatibility test.

## Related parameters {#related-parameters}

[`log_min_messages`](/parameters/log-min-messages/) · [`log_min_error_statement`](/parameters/log-min-error-statement/) · [`log_min_duration_statement`](/parameters/log-min-duration-statement/) · [`log_min_duration_sample`](/parameters/log-min-duration-sample/) · [`log_statement_sample_rate`](/parameters/log-statement-sample-rate/) · [`log_transaction_sample_rate`](/parameters/log-transaction-sample-rate/)

## References {#references}

- [PostgreSQL 19 Beta 3 — client_min_messages](https://www.postgresql.org/docs/19/runtime-config-client.html#GUC-CLIENT-MIN-MESSAGES)
- [PostgreSQL 19 release notes](https://www.postgresql.org/docs/19/release-19.html)
- [Machine-readable GUC export](/data/guc.jsonl)