Varnish Caching based on Cookie

[Thijs Cramer]

Hey Guys,

Simple question: Will varnish' cache increase in size when we add a
specific cookie to the hash? Or will varnish see that some pages
overlap in content and (eventually) evict duplicate pages from the page
cache?

I'm asking because we segment users into 20 segments by using a cookie,
but we don't want to increase our page cache 20-fold.

Thanks in advance!

- Thijs