There are two tabs on the heading of the exchange that shows your trading activity:

My orders

Entering "My orders" page you'll get a special browsing mode that will include all the orders you've created no matter their state. You can edit open/paused orders and have a look at closed ones (these aren't visible on the standard filters).

 When you cancel an order that isn't filled, it is completely deleted from history. If the order has at least one transaction, it will be kept for records but it will be removed from the listings.

My trades

This page is similar to the transactions browser on the Portfolio, but has two differences:

• The Portfolio transactions browser only lists entries for the coin you're actually seeing in the dashboard.
  On "My trades", entries for all coins are shown, and you can filter them out.
• The Portfolio transactions browser shows a total at the end of the page.
  On "My trades", they are shown only when you apply a coin filter.