Large array in database won't load in rails view

Question

I am trying to pull in data from an array into a view to form a chart. The array is stored in a database field and is very large. The array contains around 70k+ smaller arrays that look like this, [1234567890, 5]. Every time I try to render the data in a view it gets cut off. It never loads the full array so the page does not render. No errors are given. Any ideas of what may be causing this?

I am running Ruby 2.0.0-p195, Rails 3.2.13, Postgres 9.2

Answer 1

It's a pretty weird problem. It could be something timing out during fetching and just returning part of the data, depending on where it timed out.

What I'd check:

• How is the memory usage doing? Does the result improves when I add ram?
• Does it always gets cut off at the same point?
• Do you get data in batch (find_each)? Try playing with the batch size.
• Can the request itself be improved ?
• If the rails logs are fine, try looking at nginx (or whatever you use)

If all options fail try loading this asynchronously by batch by doing multiple ajax calls.