It is important to set up your Kentico site according to best practices. Failure to do so may cause headaches since you aren't using Kentico to it's full potential. In this post I will cover a case study that will highlight the importance of only getting the data that you need. Failure to properly filter / limit the data that is returned to repeaters can cause your site to run painfully slow, especially while you are editing.
Recently, a new client was complaining that their site was running very slowly and it would take forever to reload and preview a page after editing it in the CMS. After a review of their site, I found that it had not been optimized according to Kentico best practices. Here are just three things that I did to greatly improve their sites performance.
Problem: View state was enabled in all of the web parts. This results in additional overhead on page load.
Solution: Each web part allows you to disable the ViewState in the web part configuration, you can also disable ViewState for the entire web part zone.
Problem: SQL queries in repeaters were returning over a hundred columns in some cases. Pulling all of this unnecessary data from the database will slow things down.
Solution: Enter the column names into the repeater / data source web part so you only pull the content that you are using on the page.
Problem: Hierarchical viewer / navigation repeater was getting all of the pages in the content tree, even pages that weren't showing up in the nav. This client had hundreds of additional pages in a folder from an old site, and from folders in the content tree where they had been saving images and PDFs.
Solution: Ideally, old sites aren't saved in the same site and additional site files are stored in the media library. However, in this instance we had to implement a quick fix to speed things up, so we added in a condition to omit pages that were in the site files and old site path.
These are just a few ways to optimize and speed up your Kentico site, and you will sometimes find that only one or two of these things are necessary. There are numerous other ways to enhance your sites performance, learn more by reviewing Optimizing website performance in the Kentico documentation.