This summary provides a comprehensive overview of improving SQL indexing by effectively ordering columns in queries. It highlights the importance of considering trade-offs and understanding how indexes help find value ranges and sort results. The article explains various techniques for optimizing indexing, including creating efficient indexes for each table that is accessed, using column ordering to ensure retrieval of only necessary data, and leveraging index scan capabilities such as skip scans and partial indexes. The summary also emphasizes the need to evaluate benefits when creating a new index or adding a column to an existing index and to consider trade-offs between selective predicates and sorting operations.