debug_raw_expression_coverage_test — PostgreSQL configuration parameter

Enabling this forces all raw parse trees for DML statements to be scanned by raw_expression_tree_walker(), to facilitate catching errors and omissions in that function.

At a glance

What it does

Enabling this forces all raw parse trees for DML statements to be scanned by raw_expression_tree_walker(), to facilitate catching errors and omissions in that function. The default is off.

This parameter is only available when DEBUG_NODE_TESTS_ENABLED was defined at compile time (which happens automatically when using the configure option –enable-cassert).

(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 debug_raw_expression_coverage_test; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'debug_raw_expression_coverage_test';.

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 — debug_raw_expression_coverage_test.