Change the database default schema
If you are logged in as the admin user, the owner of a database, or as a user who has Alter privilege on the database, you can change the default schema by using the ALTER DATABASE command. The schema that you are making the default must exist in the database. You cannot be connected to either the current or new default schema when you run this command. For example:
MYDB.SCHEMA(USER)=> ALTER DATABASE mydb SET DEFAULT SCHEMA sch1;
ALTER DATABASE
When you change the default schema, users who have access to the database inherit access to the new default schema. If a user requires access to the previous default schema, that user must be explicitly granted access to the previous default.