Only NOT NULL is enforced in Snowflake - in ONE minute

Snowflake supports the following constraints (ANSI standard).

1. Primary Key

2. Foreign Key

3. Unique

4. Not null

A table can have only one primary key and multiple unique,foreign key and not null columns. Snowflake does not force any of these constraints except NOT NULL. These constraints can be defined on all type of tables permanent, transient, and temporary tables. Both CREATE TABLE... LIKE and CREATE TABLE... CLONE will inherit the constraints.Constraints can be defined, while creating a table, as part of column definition. Constraints can also be defined using a separate clause that defines the column. 

All constraint properties of ANSI SQL are supported like ENFORCED/NOT ENFORCED,DEFERRABLE/NOT DEFERRABLE and INITIALLY DEFERRED/IMMEDIATE.

The defaults are NOT ENFORCED, DEFERRABLE, INITIALLY DEFERRED. There are some properties ,though they are not ANSI standard, that are supported for compatibility with other DBs such as ENABLE/DISABLE , VALIDATE/NOVALIDATE and RELY/NORELY.

Note: Snowflake is a datawarehouse database not recommended for OLTP.