PHP，我应该使用json而不是mysql吗？

Question

I am thinking about creating a json/xml/text when something is inserted to mysql database, so that php page will read this instead of mysql queries. When a data has updated in mysql database, it will update json/xml files too. Is this a good idea? It seems, this will has less mysql queries so I think this can be good.

Answer 1

it seems, this will has less mysql queries so i think this can be good.

It depends. Probably not.

What you plan to do is a form of caching . If the queries used on a page are really, really complex and take a long time when benchmarking, it is sometimes a good thing to store the result in a cached file, and updating that if data changes.

But having some simple SELECT queries running on every request is nothing to worry about performance-wise. If you're not seeing any actual performance issues, you're probably best off sticking with SQL queries. A properly indexed database is really, really fast.

Answer 2

What's your goal? Gain more performance?

1st rule for performance optimization: Know your bottleneck! Don't optimize a black box. Do benchmarks before and after each optimization.

I doubt, that your database is your current bottleneck. Even it is, there are better ways to improve the performance, ie avoid statements, instead of storing the results in a json/text file.

1. Use MySQL Query cache

   MySQL is really good in caching results. You shouldn't take care of caching results yourself. Important here: enough RAM. Checkout the MySQL docs for more information: http://dev.mysql.com/doc/refman/5.1/en/query-cache.html

2. Implement more cache layer

   To gain more performance you could implement a second cache layer before the MySQL database to avoid even the call to the database. You could store the initial results (at the first call you need to get the result from the DB, of course) in a non persistent, awesome fast way using memcached or other NoSQL solutions (Redis, MongoDB to name a few).

3. Know your bottleneck

   As I said before, the most important thing in performance optimization is to know where your bottleneck is, and how much you won with a optimization. At least it's a very good feeling to stat: Hey,... after we did XYZ the system is 6000% faster. :)

Maybe your database isn't the thing which needs to be speeded up right now. Perhaps installing APC will speed up your application. :)

But coming back to you question: If you really want to store those results in JSON/text file, you should store the files in a tmpfs / RAM filesystem - so that they can be written and read very fast.

Answer 3

This really depends I suppose. If you are writing a page to be loaded with AJAX, and you have settings or configurations that are very rarely changed but needed to be loaded each time, then go ahead and write it to a json file.

If the content you are loading is dynamic or you are loading it via server side scripts, then MySQL will be a must.

Beware: If you start writing settings or data to a json file, you may encounter a million issues with security and permissions.

Answer 4

Depends on your application size. If is about few things to interact with database. you can do with JSON storing.

But If database size is large and want to use RDBMS concepts then it will be difficult to manage.

I would like you to go through this article:

MySQL-vs-JSON-file-data-storing