Rails%203%20In%20Action

This chapter covers
� Implementing pagination for resources with the
Kaminari gem
� Improving database query speeds with Active Record
features
� Caching pages and fragments of pages
� Using the Delayed Job gem with background workers
Basic performance
enhancements
When an application is written, it may be done in such a way that it will not perform
ideally. A common situation is that an application with a small database will perform
quickly because there is less data to retrieve, but starts to slow as the database
grows larger. This problem can be fixed in many different ways.
The first way is to limit the amount of data retrieved in any one call to a fixed
limit, a process known as pagination. At the moment, for example, you’re not limiting
the number of tickets shown in the show action of the ProjectsController. The
more tickets that get added to a project, the slower the page that shows this data is
going to perform because it will have to retrieve more data from the database and
render it out to the page. By breaking the data down into a set of pages, you can
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