How to temporarily disable all constraints of a schema in postgresql? - sql

Question

I need to temporarily disable all constraints and triggers of a schema in order to anonymize data in several tables. As there are dependencies between tables, I prefer to disable everything and once the anonymization treatment is over I can enable all constraints and triggers one more time.
I tried SET FOREIGN_KEY_CHECKS=0; and I got this error:
ERROR: unrecognized configuration parameter "foreign_key_checks"
SQL state: 42704
I've been reading a lot about that and some people say this is not possible.
Do you know a way to do that?
Thank you!

Answer 1

To disable foreign keys and deferrable unique and primary key constraints for a table, you can use
ALTER TABLE ... DISABLE TRIGGER ALL;
To disable all such constraints for the duration of a database session, you can
SET session_replication_role = replica;
Both tricks won't work for non-deferrable constraints and check constraints.

Answer 2

I found this solution,
I created a temporal table to keep all constraints definition:
CREATE TEMPORARY TABLE temp_constraints AS
SELECT conname constraintname, conrelid::regclass tablename, pg_get_constraintdef(oid) definition, contype
FROM pg_catalog.pg_constraint;
Then I drop all constraints:
DO $$
DECLARE constraint_name TEXT;
DECLARE constraint_table TEXT;
BEGIN
FOR constraint_name, constraint_table IN
SELECT constraintname , tablename FROM temp_constraints ORDER BY contype DESC
LOOP
EXECUTE 'ALTER TABLE ' || constraint_table || ' DROP CONSTRAINT IF EXISTS ' || constraint_name || ' CASCADE;';
END LOOP;
END $$;
And after anonymizing data I restore all constraints using the definitions in the temporal table and I drop the temporal table:
DO $$
DECLARE constraint_table TEXT;
DECLARE constraint_definition TEXT;
BEGIN
FOR constraint_table, constraint_definition IN
SELECT tablename, definition FROM temp_constraints ORDER BY contype DESC
LOOP
EXECUTE 'ALTER TABLE ' || constraint_table || ' ADD ' || constraint_definition || ';';
END LOOP;
DROP TABLE IF EXISTS temp_constraints;
END $$;
I hope this can help someone else. Thank you!