[RESOLVED] Database Caching with Codeigniter

gwerner

I know this really isn't a Codeigniter forum, but I thought I'd ask. The Codeigniter forum is hit and miss with getting replies to posts. And I never received any kind of answer on their forum.

I’m running into a situation where I need to run a query on every page load of a web site. This query really is only doing a check to see if a status has been updated. If it has, then display a message. I’d say that the status will normally be off probably 70% of the time. However, I will still need to check every page load.

Right now I have it setup to autoload the model and I do the call from MY_Controller. Is this the right opportunity to set this up as a cached query? It seems like it might, but I’m not certain when one should implement caching. My understanding is that if a status is updated, I would use that update to clear the cache. That way the next page load will create a new query a recache the data.

Does turning on caching for one query create more of a load than just loading the model and doing the query? Which method is best? Thanks for any help on this.

NogDog

My first suggestion in most such situations is to ensure it's really a performance issue before you start putting the time and effort (and dollars?) into what may be "premature optimization". Do you have any measurements or other empirical evidence that the current code is hitting any sort of performance bottleneck in this part of the app?

In any case, if you have to access the DB anyway on each page request, there's probably only a very small (relatively) performance hit if you have to run one more query -- assuming it and the associated DB tables are reasonably optimized and indexed. If you're talking about pages that otherwise would not have to hit the DB at all other than for that, then maybe you could consider CI's web page caching?

gwerner

Thanks for the reply. I really don't have any evidence one way or the other. I just wanted to get some thoughts before I moved in any direction. I will probably start with the query and see how things go. The query is really only minor. I'm just not close enough to all the ins and outs, do and don'ts and best practices when it comes to some of this. So, I thought I'd ask and see if any of the resident guru's here had advice. And, one did. Thanks again.

NogDog

It's never a bad idea to think about doing things better. 🙂 Where it gets tricky is figuring out which battles to fight. Being a typically lazy programmer, in the handful of things I've done with CI I've always ended up using the configuration option that automatically establishes a database connection on each request, so worrying about one little query usually was a relative non-issue -- it's the big queries with joins and sub-queries and un-indexed columns that should have been that were the real problems. 😉

You might find it interesting to put a bit of metering in your code just to get an idea how much time the query in question is taking you, e.g.:

$start = microtime(true);
// code to be measured
$end = microtime(true);
error_log("distinctive text here to search on: ".($end - $start)." seconds");

Then you could scan or grep your PHP error log to get a sense how much/little time that part of the code typically takes.