What is a cache?

A cache is a feature that transparently stores data so that future requests for that data can be served faster.

Your w3shop uses a number of caches to make it work as fast as possible. These include a price cache, a voucher cache, an image cache and an html cache.

If you sell designer templates, we automatically scan your w3shop six times each day to look for products which are suitable for templates. If you don't have, say, an A6 double-sided product, then we won't show any designs which are that size. Create a product, and later that day, matching designs will show up.

Why are you telling me this?

The vast majority of support queries we receive relate to changes not yet showing. If you've recently updated your products, please wait one hour before reporting missing products, missing images or incorrect prices.

What's the alternative to a cache?

We could just run queries 'live' and load images every time. If you've ever tried to compare flight prices or car insurance quotes, you'll probably have seen a "please wait while we search" message - this is an example of a database query being run live.

If we did that, your w3shop would run very slowly indeed. Instead, we pre-calculate certain things and then serve the 'saved' version to your visitors. This technique is used by many ecommerce sites.

If you're used to editing a blog or a static website, then this concept will be new to you. However, if you've build an ecommerce site or sold via third party sites, you'll know that changes don't appear 'instantly'.

What's the downsides of a cache?

Since the page might have been saved a little while ago, there could be a delay of up to one hour before changes you make to your w3shop become live. That means, if you add products, change prices, replace images, it could be one hour before your site shows them.

Why does my site feel slower after I make any changes?

Every time you change your site - adding a product, changing some text or editing images, we need to delete the 'saved' version of your page (or pages, if the change affects many things).

It doesn't matter whether you've drastically changed the page, or just fixed a typo - we need to clear the cached/saved version and create the page again.

This means the next person to view the affected page will trigger a 'redraw' and 'recalculation'. Since that person is probably you, the first time the page is viewed will be the slowest. For the second visitor onwards, the page will feel snappier.

If you make more changes, and save again, you'll be going through this cycle again. So try to make changes in 'batches'.

Why does Flyerzone feel faster than my w3shop?

The more visitors you have, the faster your site will feel. Although that sounds counter-intuitive, the more people that view a page, the less likely they're the first to view it. More visitors mean more people viewing a cached/saved version of the page.

Have you recently changed the way the cache works?

Yes. On 17th February 2014, we upgraded all our caches to run automatically when certain events triggered them. Before then, some caches had to be run manually by administrators.