This article deals with removing primary key, unique keys and foreign key constraints from a table. Please refer to Creating Indexes to understand the different treatment of indexes/constraints in Redshift.
To remove a constraint from a table, use the ALTER TABLE.. DROP CONSTRAINT command:
-- If you don't know the name of the constraint, you can look it up using:SELECT constraint_name, constraint_type
-- Then drop the constraint using the ALTER TABLE command:ALTERTABLEDROPCONSTRAINT constraint_name;