Access :: Alternative Method To The Cursor To Get The Second Part Of The List?

I have a table with 4 columns: ID, signId, storeNum, quantity with ID, SignId, and storeNum as composite primary keyif storeNum is -1, that means the quantity is the default quantity. If a store has a store-specific quantity, the storeNum is this store's number.

I need to show all rows that have specific quantity for a store, and all rows that have default quantity and of which the store does not have store-specific quantity


currently I use table-value function with storeNum as parameter to return the list. first, I get all rows that have specific quantity for a store; then, I use cursor to loop through all rows that have default quantity and check each row if the store has a specific quantity. It takes 9 seconds to run the function for a store.

The function is called within a stored procedure, which in turn is called by a function in a class, which in turn is called by a aspx code behind file. It takes about 20 seconds to load the page. 20 seconds to load a page is too long. I am trying to improve
the performance.

I wonder if there is an alternative method to the cursor to get the second part of the list.