2. Võ Duy Tuấn
Technical Director @ dienmay.com
PHP 5 Zend Certified Engineer
Mobile App Developer
Web Developer & Designer
Interest:
o PHP
o Large System & Data Mining
o Web Performance Optimization
o Mobile Development
33. PERFORMANCE EXAMPLE
• We have 1,000,000 users (customers)
• We sell 10,000 items
- Total of similarity calculating = 1,000,000 x 1,000,000 = 1,000,000,000,000
- Each similarity calculate need 0.006s (on my MacBook Pro 2.2GHz Core i7, 8G Ram)
=> We need 1,000,000,000,000 x 0.006 = 6,000,000,000(s)
≈ 70,000 days ≈ 191 years
- If store each similarity in 8 bytes, we need = 8,000,000,000,000 bytes
≈ 8,000 GB (on Memory or File)