text: -- Open PostgreSQL and connect to the sqlda database
  
  C:\> psql sqlda
  
  -- Use the EXPLAIN command to return the query plan for selecting all available records within the customers table
  
  Sqlda=# EXPLAIN SELECT * FROM customers;
  
  -- Repeat the query from step 2 of this exercise, this time limiting the number of returned records to 15
  
  Sqlda=# EXPLAIN SELECT * FROM customers LIMIT 15;
  
  -- Generate the query plan, selecting all rows where customers live within a latitude of 30 and 40 degrees
  
  Sqlda=# EXPLAIN SELECT * FROM customers WHERE latitude > 30 and latitude < 40;