Module check_inheritance 

CHECK definition merging at CREATE and ALTER inheritance boundaries.

Functions

bind_parent_check_columns

duplicate_check

merge_inherited_check

MergeCheckConstraint: a parent’s CHECK joins the constraints the new table inherits, merging with an earlier parent’s CHECK of the same name when their expressions match, an enforced copy making the merged constraint enforced.

same_check_expression

validate_check_merge

The caller decides whether a local or inherited duplicate is eligible to merge. Existing validation and enforcement states follow PostgreSQL’s directional merge rules.