Question

Suppose I have got the SQL below

How can I optimize the performance of the query ?

select product, address, quantity, 
    price, create_date, sum(no_of_photo) as no_of_photo
from
(
    SELECT customer.PROJECT_ID as project_id ,
        customer.ORDER_TYPE as order_type,  
        customer.product_name as product, 
        customer.address_name as address ,    
        customer.quantity_name as quantity,
        user.first_name || ' ' || user.last_name AS price,
        customer.create_date, customer.no_of_photo 
    FROM customer 
    INNER JOIN user 
        ON customer.creation_userid = user.userid
) master_list 
group by project_id, order_type , 
    product, address, quantity, price, 
    create_date 
having project_id = 123456 
order by product, address, quantity, price, create_date

Answer 1

A couple of things I would try:

1. Put your HAVING clause into a WHERE in the inner query
2. Select first_name and last_name on their own in inner query
3. Group by first_name, last_name in outer query (why is it called price?)
4. Do the concatenation of first_name || ‘ ‘ || last_name in outer query

Also ensure there are indexes on:

• customer.project_id
• customer.creation_userid
• user.userid