Thread: Speed when pulling data from database

Hi,
I have created an offline system which normally runs very quickly.
But when it comes to displaying more and more information in a table it starts slowing down.

Eg. Only 1 item gets displayed. People can click + or - images and it adds an addition # of item 1. (still only 1 record showing)

As people add more items, (item 2, 3, 4, 5) it now shows 5 items in the table. When people click + or - images it now slows down. It seems sluggish.

When people click + and - it changes database entry and then redirects them. When it redraws the new page it responds slower (people cant spam click + and - anymore)
Is there anyway to display the items in the table faster? or to speed up the page creation?

I think I know one way I can change it but I'm not sure about the code. At the moment its split between 2 functions. Pulling data from 2 database tables.

This is how I pull data from the database. How do I pull from multi tables in same SELECT?

PHP Code:

$sql_text = "SELECT id, minsize, maxsize FROM ".$this->TABLES[$type]." WHERE id = '$unitid' ORDER BY id"; 


By making this 1 function would it speed everything up?

has the id in every table an index? every field that is used in a where clause schould have an index, that mean these fields should defined as a key for this table...

an other break is when the indexes for the keys are so big that they couldn't stored in the RAM...