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copied!<p>As Assaf said, I wouldn't worry about storing duplicated articles if they come from different feeds, for now at least. The complication it would add doesn't benefit the few kilobytes of space you'd save..</p> <p>I suppose if you take a sha1 hash of the content, do <code>SELECT id FROM articles WHERE hash = $hash</code> and if something exists, simply have a "article_content_id" which if set points the articles content at another row... but, what if you have two articles:</p> <pre><code>id: 1 title: My First Post! feed: Bobs site content: Hi! hash: abc link: no content_link_id: id:2 title: My First Post! feed: Planet Randompeople Aggregator content: hash: abc content_link_id: 1 </code></pre> <p>..this works fine, and you've saved 3 bytes by not duplicating the article (obviously more if the article was longer)</p> <p>..but what happens when Bob decides to add adverts to his RSS feed, changing the content from <code>Hi!</code> to <code>Hi!<p><img src='...'></p></code> - but Planet Randompeople strips out all images. Then to update a feed item, you have to check each row that <code>content_link_id</code>-links against the article you are updating, check if the new item has the same hash as the articles that link against it - if it is different, you have to break the link and copy the old data to the linking-item, then copy the new content to the original item..</p> <p>There's possibly neater ways to do that, but my point is that it can get very complicated, and you will probably only save a few kilobytes (assuming the database engine doesn't do any compression itself) on a very limited subset of posts..</p> <p>Other than that, having a table of <code>feeds</code> and <code>items</code> seems sensible, and is how most other RSS-storing databases I've seen dealt with it..</p>

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