Options- PSQL

You are allowed to change how Auto Join and other options work in the Query tab.

Auto Join:

• Primary Keys with Like Names:
  This is a field or a combination of fields that uniquely and specifically identifies a record.   Your credit card number is an example of a primary key because it specifically links to your birthday, credit history, address, etc.
  
  
• Foreign Keys:
  This is a reference from Table A to a primary key in Table B.  For example, an order form in Table A shows information on purchases that are made by a customer.  It can also show this customer's ID #.  That customer ID # refers to a record in Table B that lists a specific address, phone number, name, etc for that customer.  The customer ID # in Table A is a foreign key because it links the customer's ordering information in Table A to the customer's information in Table B.
  
  
• Like Column Names:
  This is a link between two columns in with the same name found in two different tables. 

Others:

• Show Table Names:
  This gives you the option of which table each field in the Criteria menu belongs to.
  
  
  Without Tables                    With Tables
  
  
• Show Mapping Names:
  This options allows you to see the full name of the field in the tables in the Query tab.
  
  
  Without Mappings                   With Mappings
  
  
• Prohibit Cartesian Products:
  A Cartesian Product is when tables link together with no specifications.  
  
  For example, lets say we have a Table A with 3 values, A,B and C and a Table B with 3 values, 1,2 and 3.  Value A matches with value 1, value B matches with value 2, and so on.  This is a specific match. 
  
  A Cartesian product would have value A matching with 1,2 and 3, value B matching with 1,2 and 3, and so on.  Depending on what data values you have, Cartesian products can produce a very long and messy situation since it might contain unneeded information.