[wp-hackers] Re: WordPress Object Cache and WP Super Cache

[Mahmoud Al-Qudsi]

> So the question remains whether a file-based caching system is even
> necessary?  I ask this, because at work we instituted SQL dependent
> caching in our ASP.NET app, and that methodology makes the most
> sense.  It also apparently performs the best in terms of caching
> options, while file-based is dead last.

File-based *object* caching is relatively slow, but full-page HTML caching (the request doesn't even reach the ASP interpreter) is fastest though highly inflexible.

 
> It would be great if the business logic of WordPress went to a cache
> allocation and asks: "has this record/table been updated?"  If not,
> then retrieve it from cache and don't make a db query, if so then
> expire cache and get new data.

That's what the object cache current does.
It stores the result of database queries, and if that result hasn't changed it'll retrieve it from the cache. If the result has been invalidated or has expired, it'll get the new data, cache it, and use it.

-MQ