Ruby on Rails

On Aug 11, 11:07 am, Robert Walker <li...@ruby-forum.com> wrote:
>
> > So the first query is legit -- but second query is cached, and so
> > forth.  Every subsequent query ends up being a cached value, forever.
>
> > How can I make the above method *not* look at a cache?
>
> Not forever! Subsequent queries are cached until an update changes the
> underlying data. Isn't it good to read from the cache if the underlying
> database hasn't changed?
>
> I am assuming that "processed?" reads from a column in your
> pending_orders table. If something in your application changes that
> value then the query cache should be cleared automatically. However, if
> that database change were to happen outside of your Rails application I
> could see that your code could end up blocking forever.
>
It's more than that - the cache is in memory, so the cache won't be
cleared if a different rails instances touches the data

Something like

PendingOrder.uncached do
...
end

should do the trick

Fred
> In any case I would recommend adding some "circuit breaker" code to your
> method to prevent blocking forever. Maybe some sort of timeout/watchdog
> to limit the amount of time this method could block.
> --
> Posted viahttp://www.ruby-forum.com/.

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