PHP vs mySQL

[NancyJ]

Which is faster PHP or mySQL?

Now before you get all knotted ;) hear me out.

If you can do something in PHP that you can do in mySQL - should you? Which is faster, which uses more resources?

For example, is it faster or more efficient to select count() or to select and then count the result with a loop in PHP?

How about max or distinct?

Just because you can, does that mean you should?

[Phill]

For example, is it faster or more efficient to select count() or to select and then count the result with a loop in PHP?

Database. Databases have indexes on those things, there are far more efficient ways to count the number of rows in a database table then iterate all the way through in a for loop (or similar).

Also, all the data doesn't have to go through IPC (inter process communication i.e. via a socket), it can just be done in one process, which I believe speeds up the process.

How about max or distinct?

Ditto.

In general, I'd say data filtering should be done at the database level. That's what they're designed for :D

[guelphdad]

I'd agree. Do your work in your database, display your results with your application language.

[NancyJ]

I do use the db for everything possible but it seems to use a lot of CPU when I do(yes they're all indexed) - I've never actually tested to time the result - wondered if anyone had.

[cubsfan]

I would test your queries using explain and make sure they are using the appropriate index.

http://mysql.com/doc/refman/5.0/en/explain.html

I've had instances I've had to use a force index to make it use the right one.

YMMV, can't really speak to the original question, haven't tested :)

[gsnedders]

Any interpreted language (eg. PHP) will normally be slower than a compiled language (eg. C++, which MySQL is coded in).

[marek_mar]

This is actually interesting. PHP is the name of the language aswell as the interpretor of the language. The PHP intrepretor is written in c++ just like MySQL. MySQL interprest SQL which is not compiled just like PHP code.