debug_copy_parse_plan_trees — PostgreSQL configuration parameter

Enabling this forces all parse and plan trees to be passed through copyObject(), to facilitate catching errors and omissions in copyObject().

At a glance

What it does

Enabling this forces all parse and plan trees to be passed through copyObject(), to facilitate catching errors and omissions in copyObject(). 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_copy_parse_plan_trees; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'debug_copy_parse_plan_trees';.

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_copy_parse_plan_trees.