THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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In a CREATE TABLE statement, creating a primary key constraint will alter the columns nullability according to
If the <unique specification> specifies PRIMARY KEY, then for each <column name> in the explicit or implicit <unique column list> for which NOT NULL is not specified, NOT NULL is implicit in the <column definition>.
In alter statements if a users says to create a primary key on a nullable column the operation should fail.
Usage of primary key information for sources and sinks
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