Hi again all, I've been thinking about plans for implementing this and think there are some decisions to make first...
If I understand the spec correctly in that we need to know how many ratings have been made for each app at each step of 1,2,3,4 and 5, this information isn't currently returned to us by the server (review_stats() gives us appname, package name, ratings total and rating average). We need to make changes to the server for this, and my thoughts about how we approach this have come up with a few options. Option 1: maintain a field against each app on the server with the current ELR number. This would mean every time someone submits, modifies, deletes or hides a rating for that app, the server would need to re-calc the ELR at the time. The benefit of this is we can simply return the ELR to the client whenever the client asks for ratings. Because we often ask for alot of these in one hit (e.g. updates last X days) this would be a benefit performance wise where it counts. However, it would come at the cost of some time for every action that affects ratings for the app, because we need to re-calc every time. Option 2: maintain 5 fields against each app on the server, with the total ratings for each step. This would be a much simpler calculation at the time of submit/delete/modify/hide but a performance hit upon retrieval of ratings in a bulk fashion because somewhere we need to do the ELR calc for every app that has changes in ratings This could either be done by calculating the ELR on the server before returning it or just returning the 5 integers* and having the client work out the ELR. Option 3: Don't maintain any additional fields for this purpose on the server, but when asked for ratings, the server then needs to trawl through the DB to count the number of ratings at each step, before then returning either (a) the 5 integers or (b) the calculated ELR. This would be the worst performance hit at the time of retrieving ratings and is probably not viable. *We need to keep in mind, that if we go down the path of showing a distribution of ratings for each package, then we will probably need the 5 integers to be returned to the client in order to work out the distribution. With this in mind, I'd suggest we need to go with option 2 and have the server return the 5 integers to the client, who then uses them to calculate the ELR and work out the distribution of ratings for display. Thoughts? Other options? cheers Aaron _______________________________________________ Mailing list: https://launchpad.net/~software-store-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~software-store-developers More help : https://help.launchpad.net/ListHelp
