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    <p>Is it acceptable to apply a scheme used by banking, where you process all account operations once a day? Every object may have a set of (future) operations, like freeze periods, and every day the object has to make a simple decision, like: "should I expire today or not?"</p> <p>The good part is, that such daily processing is very simple to program. Also a strange renewal rules (in case you would want them) are simple to design: "is it Friday? is it the last one in this month? If yes, mark me as renewed, add some amount to required payment, or do anything".</p> <p>That would be very costly (in terms of computing power) to calculate the status dynamically, every time the object is asked. If you store the current "account", you only need more complex calculations when you want to predict future state.</p> <p>Consider it a pseudo-code:</p> <pre><code>def process(day) raise "Already processed or missed a day" unless day == last_processed_day + 1 check_expiration day check_frozen day check_anything day #... self.last_processed_day = day self.save! end </code></pre> <p>RESPONSE:</p> <blockquote> <p>Specifically, I'm wondering how your concept would deal with the recurring payment situation I've described in my original question, and in the comment that I just left on Kris Robison's answer. If I have set up a schedule of recurring payments for a given purchase, and a freeze event is scheduled for right in the middle of the payments, would the schedule of payments remain unchanged until the date of the freeze became the current date, at which time the freeze would be instituted and the payments would move forward?</p> <p>This strikes me as perhaps a great way to simplify my application, but I am wondering how users would perceive it. How would I indicate to them that the schedule of payments they were looking at when a freeze has been scheduled is no longer an accurate schedule, but will change once the freeze takes place?</p> </blockquote> <p>The "daily processing" scheme helps you with providing quick responses for questions which require complex calculations.</p> <p>You have three "groups": current state (asked often), history (almost never changing, asked relatively rarely), and future.</p> <p>Your daily processing procedure is not constrained to only update "current" state. If some event is scheduled for the processed day, the procedure probably needs to add "history" records.</p> <p>If your users will often ask questions about future (and as you said, they will), the "processing" may also create a kind of cache for these questions. For example: find (calculate) the next payment date, and write it in a helper table (a schedule).</p> <p>The main thing you need to do is to decide which questions will be asked by users, and whether you are able to calculate the responses on-the-fly or you need to have the answer prepared.</p> <p>In a bank (it varies, of course) if you ask about your current balance, they may give you the answer which was true at the beginning of the day. "Better" banks will tell you that you had X$ at the morning, but now there are also Y$ waiting for accounting.</p> <p>So, if you put a freeze record into the event queue, you may call a method, which will update the schedule at once. The same procedure (or a very similar) will or may be called in the daily processing routine.</p>
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    1. POdifficult architectural problem involving recurring payments and future events
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    1. POdifficult architectural problem involving recurring payments and future events
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    1. COI've edited my question to respond to your answer (not enough room in the comment box).
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    2. COJust wanted to thank you quickly for this - in the last couple of weeks I finally dived into this and developed a solution, and your comments were quite helpful. Between you and Kris neither are "right" but you were both helpful, and I appreciate you taking the time to answer this. Kris, if you read this, I didn't choose your answer simply because it doesn't look like you use the site any more!
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