Decrease page load time for Trending and Leaderboard page

[raj454raj]

Important observation: We have to query submission table without any condition. Why make a db query every time compute_row is called, instead keep a dictionary and pass the list of submissions to compute_row corresponding to the user.

[raj454raj]

We prefer page load optimization over code cosmetics ;)

[raj454raj]

https://github.com/stopstalk/stopstalk-deployment/blob/master/controllers/problems.py#L303 Remove this for loop and put SQL IN in the query

[raj454raj]

Store globally trending problems in a table and run a cron to update it?

[raj454raj]

Still some scope to improve time by removing sql query in loop

[raj454raj]

As the number of users are increasing - Leaderboard is slowing down.! Optimize fast.

[raj454raj]

Why compute everything on every pageload ? Cron to update a particular db table that stores the previous rating and other stuff?

[raj454raj]

Can find a query to get streak of a user - here

[raj454raj]

Leaderboard page - This query is taking most of the time. Calculate this result in cron and create a SQL VIEW. When should we update the VIEW -

• In update-submissions.py
• After all the three submissions1, submissions2 and submissions3 have executed.

[raj454raj]

Next is to optimize LeaderBoard page, trending page done.

[raj454raj]

Deployment procedure for maintaining new columns of rating directly.