Hi,
I am making a db using sqlite3 with python , but my question is pretty general I think even if you don't know this db system you can probably help me. I am trying to decide what the best key(s) are to use in a table. Here is what it might look like using the common tutorial analogy:

Customer, OrderDate
A, 2012-1-1
A, 2012-1-2
B, 2012-1-1
B, 2012-1-2

In my db there could be 50 customers but each customer could in extreme cases have 10000 OrderDates! My application will repeatedly be selecting all the orders from one customer between a date range.

Is there any way that I can set up the primary keys so that this type of query will be more efficient? Customer + OrderDate will be unique, will there be any advantage of making these combined columns the primary key since I will only query for date ranges and not specific dates?

My expectation is not that this will run in seconds but I would like to avoid taking 30 minutes if it could take 5...

Thanks so much for your help!

Switch the order of the columns, use OrderDate then Customer to get the best of both worlds!

-PatP

Thanks Pat! Could you explain why this would help?