ignore_system_indexes — PostgreSQL configuration parameter

Ignore system indexes when reading system tables (but still update the indexes when modifying the tables).

At a glance

What it does

Ignore system indexes when reading system tables (but still update the indexes when modifying the tables). This is useful when recovering from damaged system indexes. This parameter cannot be changed after session start.

(Description quoted from the official PostgreSQL documentation.)

How to apply a change

Can be set per session with SET, per role/database with ALTER ROLE/DATABASE ... SET, or globally in postgresql.conf.

Inspect the current value and source with SHOW ignore_system_indexes; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'ignore_system_indexes';.

Tuning guidance

This is a developer and debugging aid, not a performance knob. Leave it at the default in production; enable it only temporarily, on a non-production or carefully controlled system, while diagnosing a specific problem. Several options in this group add overhead, generate large volumes of log output, or can damage data if misused — turn them off again as soon as the investigation is done.

Reference

PostgreSQL documentation — ignore_system_indexes.