How does Reddit sort query their database for "what's hot"?

Question

I want to implement something similar on my site.

Submissions have up_votes and down_votes. I'd imagine reddit does some sort of database query that takes into account the up_votes vs. total_votes and maybe factors in # of views and # of comments and limits it all by a specified time period.

What sort of query do you imagine they use to determine this?

Thanks!

The best way is to just look over their [source code](http://code.reddit.com/). — alex, May 16 '11 at 08:13
@hammar - this is exactly what i was looking for. submit it as an answer and i'll checkbox it. thanks! — goddamnyouryan, May 16 '11 at 08:39

score 6 · Accepted Answer · answered May 16 '11 at 08:52

6

For links, they use a formula based on upvotes minus downvotes combined with age of the post.
For comments, they use a confidence sort based on a Wilson score interval.

This blog post describes both formulas in greater detail.

answered May 16 '11 at 08:52

hammar

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How does Reddit sort query their database for "what's hot"?

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