Hi Everyone!

I'm designing a database for a company and I came across the following dilemma. Almost every table I have to create must include two id's (it's some sales stuff) coworker id and costumer id and some other columns. For example there's the sales table. Which one is better for these kind of structures:

1: keep the common ids in every table like this:

sales table:
--sales id
--coworker id (foreign key)
--costumer id (foreign key)
--detail1
--detail2
--
--
--etc.

or

2: create a junction table like this:

sales table:
--sales id
--detail1
--detail2
--
--
--etc.

junction table1:
--sales_coworker_id
--sales id
--coworker id

I know that with the junction tables you have to create the joins or views if you want to get all the details of one sale and I think it's slower than keeping it in the sales table but how much. And is there any benefit of creating a junction table structure like the one above?

Thanks for the help!