Problem with long site load time and database

[coco_jambo]

Hi.

 

I have a problem with my prestashop site regarding load times.

It's very long, varying between 7 to 10 seconds, apperently the thing that takes the longest is "time to first byte".

 

The site is working on a shared hosting.

 

Here are the webpage tests:

http://gtmetrix.com/reports/diagnostykakominowa.pl/LTgyWl5I

http://www.webpagetest.org/result/131202_73_K1S/

 

I also noticed that my database has over 150 000 + entries why's that? I have about 80 products on the site?

I added CDN "cloud flare" to the site but nothing really improved, and I can't use memcached because of the hosting's "custom" cache. Also I tried to set "expires" in my .htaccess but as seen in those tests the command seems to be completely ignored.

 

What can I do to improve my site's performance?

 

Best regards.

 

edit: I should mention that I use the default theme slightly modified here and there <mostly regarding colors> and prestashop's version is 1.5.1.0.

Edited December 2, 2013 by coco_jambo (see edit history)

[coco_jambo]

Can anyone please help? I can provide more details if needed...