Performance issues

[DimitriDV]

Hi there,

 

we have a lot of performance issues on our website and we are investigating the cause. I asked one of our php developers if a high amount of mysql queries (on the same page) could be the cause of our slow website. I asked this because we have more than 100 queries on each page.

 

 

I suggested to use the JOIN statement to reduce the number of queries and this was his response:

 

The basic rule of thumb when we use mysql is -

Regardless of what back end you choose the mysql query engine is week. It only supports nested loop scan, no merge join, no hash join, nothing fancy. Further sub quires can’t even use indexes so they are near useless. The rule when using mysql is *don’t join*. So the case where mysql can be put to good use is where all your quires are over a single table, which is why it has done well for web apps I wold suspect.

 

 

 

 

Can someone AGREE or DISAGREE with this statement? Thanks!

[JonnoTheDev]

Regardless of what back end you choose the mysql query engine is week. It only supports nested loop scan, no merge join, no hash join, nothing fancy. Further sub quires can’t even use indexes so they are near useless. The rule when using mysql is *don’t join*. So the case where mysql can be put to good use is where all your quires are over a single table, which is why it has done well for web apps I wold suspect.

This is absolute garbage.

 

we have more than 100 queries on each page

You seriously need to think about redesigning your db structure and codebase.

 

I suggest you purchase a mysql 5 book for your developer.