Right. My point was that you shouldn't concern yourself with getting stale values from the database because you cached them, and they changed short of the refresh interval. I have a website that caches things for 15 minutes, and I just tell my users that they won't see changes (on certain things) until 15 minutes have passed. For example, they add a new contact, the new contact won't be shown in the list of contacts until after 15 minutes, because that contact list is huge, and having to get it from the database every time can be slow. Now they can pass around links to the new contacts if they absolutely need to share it before that 15 minutes has passed, but otherwise, if they wait it will show up. If the 15 minute wait was getting too slow for them, I can of course decrease the cache time. My site has two layer cache as well, so not only is the data cached in ram for 15 minutes, but it's also cached on the browser by setting the caching options in the header. 95% of the time, the server can just send a 304 message.
On Friday, July 13, 2012 2:12:28 PM UTC-7, Anthony wrote: > > Right, you are using a ram cache, so you would have to explicitly >> invalidate the cached items if you want to update them. I would not rely on >> the time_expire to handle that for you, unless you are really not too >> concerned about it. > > > To be clear, the cached value will reliably get updated whenever the time > since the previous save exceeds the current value of time_expire, so you > can rely on time_expire to update based on the interval it specifies. > Nevertheless, there may be times you want to update the cached value based > on something other than the time that has expired since the last update. > That is possible as well, though a separate issue. > > Anthony > --
