[pLog-svn] Improving performance of summary.php

[Oscar Renalias]

Let's face it, summary.php is still slow :-)

I was thinking about this and I found two possible solutions (that  
are not mutually exclusive, by the way):

- Somebody logged a feature request in mantis asking for summary  
templates that are not removed when a change in data occurs, but  
instead, that expire after a certain period of time. Something like  
15 min or so. This would confuse some users but we would only need to  
generate the front page 4 times per hour, instead of many more in  
case of busy sites.

- Instead of calculating the lists of most recent and commented  
articles, blogs, etc every time we generate the front page of  
summary.php, we should calculate these lists every time somebody  
posts, updates or deletes an article and then  store the id of these  
articles and blogs in some temporary table. This would slow down  
operations with blog articles but should theoretically speed up  
loading summary.php.

I haven't tested any of these approaches yet. But does anyone have  
any comments or further ideas?

Oscar