SQL - faster to filter by large table or small table - sql

Question

I have the below query which takes a while to run, since ir_sales_summary is ~ 2 billion rows:
select c.ChainIdentifier, s.SupplierIdentifier, s.SupplierName, we.Weekend,
sum(sales_units_cy) as TY_unitSales, sum(sales_cost_cy) as TY_costDollars, sum(sales_units_ret_cy) as TY_retailDollars,
sum(sales_units_ly) as LY_unitSales, sum(sales_cost_ly) as LY_costDollars, sum(sales_units_ret_ly) as LY_retailDollars
from ir_sales_summary i
left join Chains c
on c.ChainID = i.ChainID
inner join Suppliers s
on s.SupplierID = i.SupplierID
inner join tmpWeekend we
on we.SaleDate = i.saledate
where year(i.saledate) = '2017'
group by c.ChainIdentifier, s.SupplierIdentifier, s.SupplierName, we.Weekend
(Worth noting, it takes roughly 3 hours to run since it is using a view that brings in data from a legacy service)
I'm thinking there's a way to speed up the filtering, since I just need the data from 2017. Should I be filtering from the big table (i) or be filtering from the much smaller weekending table (which gives us just the week ending dates)?

Answer 1

Try this. This might help, joining a static table as first table in query onto a fact/dynamic table will impact query performance i believe.
SELECT c.ChainIdentifier
,s.SupplierIdentifier
,s.SupplierName
,i.Weekend
,sum(sales_units_cy) AS TY_unitSales
,sum(sales_cost_cy) AS TY_costDollars
,sum(sales_units_ret_cy) AS TY_retailDollars
,sum(sales_units_ly) AS LY_unitSales
,sum(sales_cost_ly) AS LY_costDollars
,sum(sales_units_ret_ly) AS LY_retailDollars
FROM Suppliers s
INNER JOIN (
SELECT we
,weeekend
,supplierid
,chainid
,sales_units_cy
,sales_cost_cy
,sales_units_ret_cy
,sales_units_ly
,sales_cost_ly
,sales_units_ret_ly
FROM ir_sales_summary i
INNER JOIN tmpWeekend we
ON we.SaleDate = i.saledate
WHERE year(i.saledate) = '2017'
) i
ON s.SupplierID = i.SupplierID
INNER JOIN Chains c
ON c.ChainID = i.ChainID
GROUP BY c.ChainIdentifier
,s.SupplierIdentifier
,s.SupplierName
,i.Weekend