client_min_messages

Definition PG 18 manual

Controls which message levels are sent to the client. Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, LOG, NOTICE, WARNING, and ERROR. Each level includes all the levels that follow it. The later the level, the fewer messages are sent. The default is NOTICE. Note that LOG has a different rank here than in log_min_messages.

INFO level messages are always sent to the client.

How it works

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.

Operational considerations

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.

Workload guidance

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.

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.

SMALL: Leave the default NOTICE unless client chatter is measured as a problem; suppressing messages does not materially increase server capacity.