ALTER TABLE support

[fulghum]

ALTER TABLE is commonly used in import SQL scripts. Adding foreign keys after loading data into tables appears to be one of the more common uses in import scripts.

Examples:

• Chinook_PostgreSql_utf8.sql uses ALTER TABLE to add foreign key constraints to created tables after data has been loaded.
• dellstore2-normal-1.0.sql uses ALTER TABLE to add primary key constraints as well as foreign key constraints after data has been loaded.

 
Use cases:

• Add primary key
• Add foreign key constraint
• Alter owner